REST APIs are the interface between clients and servers that allows for data to be shared across platforms, providing a seamless connection between applications, databases, and other resources. A REST API Developer is the programmer who helps clients connect their applications to a certain platform and ensure data is flowing between the two in an efficient, secure manner. This can help to reduce friction, improve performance & scalability, boost security, streamline website navigation, and more.

REST API Developers build and maintain custom programming to enable automated data retrieval and communication with a client’s desired application or platform. This can encompass services such as quickly integrating third-party payment systems into an existing website, minimizing manual work and improving customer experience. They may also incorporate priority systems; for example creating different APIs for handling bulk vs single requests for heavy workloads. Ultimately a REST API Developer helps clients bridge the gap between complex platforms and transform data into valuable business insights.

Here’s some projects that our expert REST API Developers made real:

  • Establishing communication between different applications
  • Creating priority systems for managing large volumes of requests
  • Integrating third-party payment systems into an existing website
  • Developing programming to seamlessly retrieve dynamic data
  • Designing secure connections to protect confidential information

Our highly-skilled REST API Developers are experts when it comes to stitching together the critical links which connect disparate platforms together. With years of experience they have been able to tackle innumerable projects which have led to successful outcomes for our clients. If you have an issue related to connecting your application with another platform or require automated data retrieval services then you can post your own project here on Freelancer.com and hire one of our experienced developers today!

Od 57,517 ocen, stranke ocenjujejo REST API Developers 4.9 od 5 zvezdic.
Najem REST API Developers

REST APIs are the interface between clients and servers that allows for data to be shared across platforms, providing a seamless connection between applications, databases, and other resources. A REST API Developer is the programmer who helps clients connect their applications to a certain platform and ensure data is flowing between the two in an efficient, secure manner. This can help to reduce friction, improve performance & scalability, boost security, streamline website navigation, and more.

REST API Developers build and maintain custom programming to enable automated data retrieval and communication with a client’s desired application or platform. This can encompass services such as quickly integrating third-party payment systems into an existing website, minimizing manual work and improving customer experience. They may also incorporate priority systems; for example creating different APIs for handling bulk vs single requests for heavy workloads. Ultimately a REST API Developer helps clients bridge the gap between complex platforms and transform data into valuable business insights.

Here’s some projects that our expert REST API Developers made real:

  • Establishing communication between different applications
  • Creating priority systems for managing large volumes of requests
  • Integrating third-party payment systems into an existing website
  • Developing programming to seamlessly retrieve dynamic data
  • Designing secure connections to protect confidential information

Our highly-skilled REST API Developers are experts when it comes to stitching together the critical links which connect disparate platforms together. With years of experience they have been able to tackle innumerable projects which have led to successful outcomes for our clients. If you have an issue related to connecting your application with another platform or require automated data retrieval services then you can post your own project here on Freelancer.com and hire one of our experienced developers today!

Od 57,517 ocen, stranke ocenjujejo REST API Developers 4.9 od 5 zvezdic.
Najem REST API Developers

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    I need a production-ready crypto exchange site that lets users trade on a live spot market with Bitcoin, Ethereum, Ripple and USDT from day one, with the option to add more pairs later. Real-time order books, depth charts, trade history and WebSocket price feeds should feel as fast as the major exchanges. Security is the main priority. The build must ship with strong account protection (2FA, email/SMS verification), cold-wallet segregation for the majority of funds, hot-wallet limits, and an architecture that can absorb DDoS spikes without downtime. Please plan for regular penetration testing and clear audit logs. A clean React (or Vue) front-end talking to a Node.js, Go or comparable back-end is preferred, but I’m open to other proven stacks if you can demonstrate equal or better ...

    €609 Average bid
    €609 Povprečna ponudba
    19 ponudb

    I’m ready to turn my working title “GoGogogogogp” into a fully-featured Android application. The project is strictly app development—no web or iOS work for now—so I need someone who can take the idea from blank screen to a polished release on Google Play. Here’s what the engagement will look like: • Collaborate with me to refine the feature set, then translate it into a clean, modern Android interface. • Build the app natively in Kotlin or Java inside Android Studio, following Material Design best practices for performance and accessibility. • Connect any required back-end services (Firebase, REST API, or a solution you recommend) and implement secure local data storage. • Run thorough functional and usability tests, fix bugs,...

    €8 / hr Average bid
    €8 / hr Povprečna ponudba
    26 ponudb

    I’m building an AI-driven personal-assistant chatbot that runs on a Node.js + Express backend with MongoDB for persistence and Groq’s API for the language layer. The goal is to give users a fast, intelligent helper that works seamlessly on both web and mobile screens. Scope of work • Architect or refine the RESTful endpoints that receive user questions, forward them to Groq, and stream answers back in real time. • Create (or polish) a responsive web interface and a companion mobile experience so the conversation feels native on any device. • Persist every message, plus metadata needed for analytics, inside MongoDB and expose a history endpoint that can be filtered by user and date. • Build two key features into the assistant itself: – Task...

    €317 Average bid
    €317 Povprečna ponudba
    50 ponudb

    Our ServiceNow instance handles the full ITSM ticket load—incidents, changes, service requests, essentially every standard IT ticket we raise. Today many of those steps are still manual, scattered across e-mails and ad-hoc approvals. I need those repetitive touches removed and replaced with robust, auditable automation built directly in ServiceNow. Scope of work • Build advanced, rules-driven workflows for Incident, Change and Service Request management using Flow Designer (or the legacy Workflow Editor where it still makes sense). • Orchestrate cross-module hand-offs so a single ticket can trigger follow-on tasks or child records automatically—no swivel-chairing across modules. • Leverage IntegrationHub and REST/Scripted APIs where outside data or externa...

    €222 Average bid
    €222 Povprečna ponudba
    11 ponudb

    I use Stripe Checkout links to sell monthly subscriptions and I run my AI video service through the Runway ML API. What I need is a small, secure webhook that listens to Stripe events, recognises the subscription tier a customer just paid for, and immediately calls the Runway ML REST endpoint to top up that customer’s usage. The flow should handle multiple subscription tiers (Basic, Pro, etc.), mapping each tier to a different credit amount in Runway ML. On a successful payment— or —the webhook must: • validate the Stripe signature • read the product / price ID to identify the tier • post the correct credit to Runway ML via its REST API • log the action to prevent double-crediting and for later auditing • return a 200 response so Stripe ...

    €505 Average bid
    €505 Povprečna ponudba
    227 ponudb
    Web Prototype for Digital Lending
    6 dni left
    Verificirano

    I already have a fully tested Spring Boot micro-service layer, a Flutter mobile app in production, and a complete set of Figma screens. What I now need is a browser-based prototype—about twenty responsive pages—built with Vibe coding so that customers can complete the digital-lending journey from any device. Scope • Core purpose: present a self-service interface for borrowers. • Key pages that must be functional in this first cut are the Loan Application Form and the personalised User Dashboard. Transaction history and other back-office views can remain stubs for now. • All data, authentication, and business rules come from the existing REST endpoints; no additional server logic is required—just clean, well-structured API wiring on the front end. As...

    €250 Average bid
    €250 Povprečna ponudba
    52 ponudb
    Angular Lending Onboarding Web UI
    6 dni left
    Verificirano

    The mobile app for this lending platform is already live, and every middleware endpoint has been built and tested in Spring Boot. Now I need the browser-based front end. Your task is to turn my finished Figma designs into a production-grade Angular application that mirrors the mobile experience and runs flawlessly on modern browsers. Around 20 screens are required to be developed based on Figma designs we have already ready You will build responsive components, hook them into our existing REST and WebSocket endpoints, implement JWT authentication (including silent refresh), and deliver a fully tested codebase. Pixel-perfect fidelity with the designs, smooth real-time updates throughout the onboarding flow, and clean, maintainable TypeScript are critical. Deliverables • Complete An...

    €223 Average bid
    €223 Povprečna ponudba
    49 ponudb

    I’m ready to turn PageVault’s lightning-fast compression API into the backbone of a multi-channel eBook storefront. The core task is to wire the existing REST endpoints so they not only shrink large publication files on the fly but also let customers purchase and download them seamlessly. Here’s what the finished solution should do: • Accept an uploader’s original EPUB, MOBI or PDF, route it through the PageVault compression service, then store the optimized asset in my cloud bucket. • Push the final, compliant files to Amazon Kindle, Apple iBooks and Google Play Books from a single dashboard, keeping each platform’s metadata requirements in mind. • Present buyers with a secure payment gateway (Stripe preferred, though I’m open to a...

    €447 Average bid
    €447 Povprečna ponudba
    111 ponudb

    I need a custom Pine Script / TradingView tool for my multi-chart setup (8-chart layout). Requirements: - I use an 8-chart synchronized layout in TradingView. - When I double-click on any candle in one chart, I want the script/tool to automatically detect that exact candle on the other 7 charts as well (same timestamp/date-time candle). - After detecting the same candle across all charts, it should automatically draw a highlighted box/zone using: - Candle Open - Candle High The box/zone should appear automatically on all 8 charts at the corresponding candle position. Detailed behavior: 1. I double-click a candle on Chart 1. 2. The script identifies the candle timestamp. 3. On the remaining 7 charts, it finds the candle with the same timestamp. 4. It automatically creates a rectang...

    €20 Average bid
    €20 Povprečna ponudba
    19 ponudb

    I'm looking for an experienced full stack developer to join our team building a multi-platform, large-scale, multi-layer, Platform leveraging REST APIs, JSON data exchange, and RBAC/Token-based User access to a backend content and process management system (CPMS). Ideal skills and experience: - Strong experience with REST APIs - Proficiency in backend technologies (Swift) - Knowledge in database management (PostgreSQL) - Experience in secure user authentication RBAC systems - Familiarity with mobile app development and integration - OOP: Swift, SwiftUI, and Embedded Swift - U.S. Citizenship & Residency (required) Please provide examples of similar projects you’ve completed. - Github - Resume

    €43 / hr Average bid
    Lokalno
    €43 / hr Povprečna ponudba
    49 ponudb

    Quiero que mis procesos internos funcionen solos gracias a n8n. El primer paso es conectar el flujo con nuestras herramientas de gestión de proyectos (Asana, Trello, Jira, Monday u otras que utilices con soltura) para que la creación de tareas, los cambios de estado, las asignaciones y las notificaciones se disparen de forma automática según las reglas que definiremos juntos. Dispongo de una instancia self-hosted de n8n y de las credenciales API necesarias. Tu trabajo consiste en diseñar los workflows, configurarlos, probarlos a fondo y dejarlos listos en producción. Busco además que documentes cada paso para que el equipo pueda darles mantenimiento sin depender de terceros. Entrego esquema de procesos y accesos de prueba; necesito de tu p...

    €124 Average bid
    €124 Povprečna ponudba
    63 ponudb

    My WordPress site doesnt accept REST calls from n8n. Every POST request I send to /wp-json/wp/v2/posts with my administrator credentials is rejected with the following response: `{ "code": "rest_cannot_create", "message": "Sorry, you are not allowed to create posts as this user.", "data": { "status": 401 } }` No plugins or themes were updated before this occurred, and the account in question is a full Administrator. I need a WordPress-savvy developer who can: • Trace why the REST endpoint believes the admin lacks create permissions. • Adjust any capability, role, or permission settings that may have been corrupted. • Prove success by requesting me to send a test through n8n Once the 401 is gone and posts flo...

    €123 Average bid
    €123 Povprečna ponudba
    164 ponudb

    We are looking to build an Agent AI which : Takes the input of quotation request from Email, PDF, Images, Website Enquiry Extract the data of enquiry and check the erp system to match the right products for the requirement Prepare a quotation based on the customer requirement and available products Checks wheather the quotation is right or not Sends to sales team for approval and once approved sends to end customer ERP is already there and built with PHP. API's should be created from ERP to communicate with Agent. Agent should be able to understand products and map them with customer requirements through cementic approach. Agent should not invent. We need to know the cost and timeline if : Agent is built from scratch using LLM, LangGraph, Python etc and if created using already...

    €8 / hr Average bid
    €8 / hr Povprečna ponudba
    35 ponudb

    I’m launching Sahal Pharma, a lean B2B marketplace that will let hospitals, pharmacies, suppliers—and even a few duty-free outlets—trade medicines and medical supplies online here in Somalia. Think of it as a stripped-down Farmazon: the first release simply has to work, prove the concept, and give us a codebase we can extend later. Scope of this MVP • Core features: product listings with fast search, a straightforward order-management flow, and secure user authentication/authorization. • User roles: Admin (system control), Buyer (hospitals & pharmacies), and Seller (suppliers). • Responsive web app first, with a clean REST/GraphQL layer so a mobile client can plug in later. • Any modern stack is fine—Laravel, Django, Node/Express, or...

    €168 Average bid
    €168 Povprečna ponudba
    131 ponudb

    I'm seeking a developer experienced in integrating Zoho applications with various AI APIs. The integrations required are: - Zoho CRM, Zoho Desk, Zoho Projects - OpenAI API, Claude API, WhatsApp API, Whisper AI - n8n or - REST API experience - Zoho Deluge scripting Ideal skills and experience: - Proficiency in Zoho applications and their APIs - Strong expertise in OpenAI and Claude APIs - Experience with WhatsApp API and Whisper AI - Familiarity with n8n or for automation - Solid REST API knowledge - Ability to write and understand Zoho Deluge scripts Looking for a freelancer who can efficiently set up these integrations to enhance our workflows.

    €475 Average bid
    €475 Povprečna ponudba
    44 ponudb

    I’m putting together a new suite of apps—one web-based, one native for Windows—that will focus entirely on customer interaction management. At the heart of both versions will be three core features my team relies on every day: real-time live chat, smooth email integration, and detailed call logging. The goal is to give users a consistent, latency-free experience whether they open the browser on the road or fire up the desktop client in the office. I already run an in-house CRM, so you will be working with an existing database schema and authentication flow; however, the interaction module you build will be green-field. A single shared backend (REST or GraphQL is fine) should power both the web app—ideally React or Vue—and the Windows desktop client, which can...

    €2545 - €4241
    Zapečateno
    €2545 - €4241
    80 ponudb

    I’m enhancing a full-stack delivery platform and now need help on the frontend side only. The backend APIs (Node.js / Express with a MySQL data layer) are in place; your focus will be the HTML, CSS and vanilla JavaScript interface that sits on top of them. Core scope • Customer module – build the profile management screens with clean, intuitive navigation. • Order workflow – take charge of the entire order-processing interface; this is an end-to-end development task, from “create order” through every status change until completion. • Driver & tracking dashboard – consume the existing real-time endpoints and render live maps, route details and ETA updates in a single view. UX & performance goals The UI must stay lightwei...

    €428 Average bid
    €428 Povprečna ponudba
    113 ponudb

    We are looking for an experienced web developer or development team to help build an investment platform web application. The platform will be designed to provide a seamless and secure environment for users to invest in various assets, view portfolio performance, and track market data in real-time. This is a full-stack web application, and we expect the developer to have experience in both front-end and back-end development. The project requires integration with financial data providers for real-time stock/asset prices, a user-friendly interface, secure account management, and investment tracking tools. Key Features: User Registration and Authentication: Secure sign-up/login with multi-factor authentication. Investment Dashboard: A clean, user-friendly dashboard where users can view thei...

    €1282 Average bid
    €1282 Povprečna ponudba
    300 ponudb

    I’m building an end-to-end pipeline that will find videos on my NAS and upload it to another video platform, the important things are: • Encode: Transcode every incoming file into the adaptive formats my player expects (H.264/H.265 + multiple bit-rates). • Legal docs: Locate the matching licence, model release or rights agreement in our internal store (or an external source I’ll specify), attach it as metadata, and flag if anything is missing. • AI analysis: Before upload, run sentiment analysis and scene segmentation on the video so I can generate chapter markers and compliance notes. - encode the video with ffmpeg to be between 13 and 20 minutes • Upload: Push the processed file, metadata and AI insights to my platform via its REST/GraphQL end...

    €8 / hr Average bid
    €8 / hr Povprečna ponudba
    20 ponudb

    We are looking to build an Agent AI which : Takes the input of quotation request from Email, PDF, Images, Website Enquiry Extract the data of enquiry and check the erp system to match the right products for the requirement Prepare a quotation based on the customer requirement and available products Checks wheather the quotation is right or not Sends to sales team for approval and once approved sends to end customer ERP is already there and built with PHP. API's should be created from ERP to communicate with Agent. Agent should be able to understand products and map them with customer requirements through cementic approach. Agent should not invent. We need to know the cost and timeline if : Agent is built from scratch using LLM, LangGraph, Python etc and if created using already...

    €3338 Average bid
    €3338 Povprečna ponudba
    27 ponudb

    Our marketing pages and main dashboard are built with React 18, Next 13 (mix of SSR, SSG, a little ISR), TypeScript, Tailwind and Redux. Traffic is growing fast and the first pain point is plain-and-simple load time; I’m watching TTFB and FCP drift past our targets and I want that trend reversed before the next release goes live. You’ll step in as a senior owner of the frontend layer, profile what’s dragging us down and ship the fixes. Six years of hands-on React/Next work is essential because I need somebody who recognises anti-patterns instantly and can move from audit to optimisation without a long ramp-up. The stack also touches SCSS, REST endpoints, Jest tests and a bit of Redis-backed caching, so fluency there is useful even though the core focus stays on the br...

    €469 Average bid
    €469 Povprečna ponudba
    95 ponudb

    I need a compact micro-service written in Go that reaches out to our external hotel-inventory supplier, pulls down hotel name and location data, current room availability, and live pricing, then surfaces that information through a clean set of REST endpoints. Core behaviour • Fetch and refresh data from the supplier API on a configurable schedule, respecting their rate limits. • Expose a /search endpoint that lets callers filter results by city, hotel name, and amenities (all three must work in any combination). • Return concise JSON with the matching hotels, available rooms, and prices, ready for direct use by our front-end team. • Handle errors, time-outs, and partial failures gracefully so the API never blocks a request thread. Implementation notes Please...

    €26 Average bid
    €26 Povprečna ponudba
    10 ponudb

    BACKEND LEAD ENGINEER — FOOD INTELLIGENCE PLATFORM Node.js · TypeScript · PostgreSQL · Prisma · REST API Budget: $750 USD · Fixed Price ─────────────────────────────────────── ABOUT THE PROJECT We are building a Food Intelligence Platform across 7 phases — from data infrastructure through to a consumer grocery app, condition-specific health apps (diabetic, cardiac), genomic personalization, hospital integrations, and an enterprise B2B layer. Phase 1 is backend foundation work. The platform is designed to scale globally across US, EU, Asia, Middle East, and Africa. This is not a small project. If you deliver Phase 1 well, there is a high probability of continued full-time engagement across all remaining phases. We are looking for someone wh...

    €478 Average bid
    €478 Povprečna ponudba
    149 ponudb

    We are looking for experienced freelance developers and agencies who want to build custom e-commerce storefronts using our existing headless commerce platform Our API-first commerce backend already provides: Products and categories Shopping carts and orders User management Reviews Invoice generations REST APIs Multi-tenant infrastructure Scalable backend services We need frontend developers who have potential clients can create modern online stores using technologies such as: React Vue Angular PHP Twig Custom frontend stacks Project responsibilities: For brands and agencies that want Shopify-like commerce infrastructure without Shopify’s frontend/plugin chaos Build responsive storefronts Integrate with REST APIs Develop product, cart, and checkout flows Create custom UI/UX ex...

    €16 / hr Average bid
    €16 / hr Povprečna ponudba
    207 ponudb
    Manage SMS Automation Developer
    3 dni left
    Verificirano

    I need an experienced Project Manager who can take full ownership of an upcoming SMS-based automation build. Your first task will be to source and hire the right freelance developer, then guide the work from concept through launch. Because the core of this project is SMS automation, I expect you to feel comfortable discussing message routing, webhook callbacks, and typical platforms such as Twilio or similar REST-style gateways. Strong technical expertise lets you translate my business goals into clear developer tickets, while solid communication skills keep every stakeholder on the same page. Scope of your involvement • Draft a concise project brief and candidate screening rubric • Interview and select the developer on my behalf • Define milestones, timelines, and qua...

    €19 / hr Average bid
    €19 / hr Povprečna ponudba
    205 ponudb

    I have an existing Windows desktop application (built in Visual Studio). The app is fully functional and serves as a fitness application. I am looking for an experienced full-stack developer (or team) to analyze the existing app and build a modern web-based version with similar functionality and improved UX/UI. Scope of Work: Review and understand the existing Windows application (source code provided) Run, test, and document current functionality Rebuild the application as a web app Improve UI/UX where appropriate Ensure scalability and performance Preferred Tech Stack: Frontend: React / (preferred) OR Flutter / React Native (if proposing cross-platform approach) Backend: Node.js + Express REST or GraphQL APIs Firebase (optional) CMS / Content: Headless CMS (Strapi, Sanity, or si...

    €1960 Average bid
    €1960 Povprečna ponudba
    202 ponudb

    What You’ll Do Design and build scalable backend services for a SaaS platform Develop secure, high-performance RESTful APIs Implement multi-tenant architecture with proper data isolation Design and optimize PostgreSQL schemas, queries, and indexes Implement authentication and authorization (JWT, OAuth, RBAC) Integrate third-party services (payments, notifications, storage, etc.) Ensure performance, security, and reliability in production Contribute to backend architecture, standards, and best practices Must-Have Requirements 3+ years of backend experience on real SaaS products Strong proficiency in Node.js (preferred) or equivalent backend stack Experience designing and implementing multi-tenant systems Strong knowledge of PostgreSQL or equivalent DB Experience building secure produ...

    €279 Average bid
    €279 Povprečna ponudba
    43 ponudb

    I need a working Aviator predictor (version 12) that focuses on real-time predictive analytics. All incoming data will arrive through an API I already have, so your first step is to hook the model up to that feed, validate the data stream, and keep it in sync with low latency. Core goals • Ingest real-time game data via my API. • Generate a live prediction for each round with clear confidence scoring. • Display the next outcome locally (CLI or lightweight web view) and expose it through a simple REST or WebSocket endpoint so I can embed it elsewhere. • Log every prediction with a timestamp so we can back-test performance. What I’m looking for • Clean, well-commented code in any mainstream language (Python, Node.js, or similar). • A lightweight ...

    €18 Average bid
    €18 Povprečna ponudba
    3 ponudb

    I’m building a content-driven site and need a solid Python backend—Django is my first choice, though I’m open to Flask if there’s a compelling reason. The project centres on a full-featured blog / content-management system with clear role-based access control: admins oversee everything, editors handle day-to-day content, and subscribers enjoy read-only access. What I’m looking for • A clean, well-structured codebase with reusable Django apps for posts, categories, tags, and comments • Robust authentication and authorisation wiring the Admin, Editor, and Subscriber roles to the appropriate views and API endpoints • An intuitive Django admin customised for non-technical editors (inline editing, search, filters) • RESTful (or GraphQL,...

    €215 Average bid
    €215 Povprečna ponudba
    47 ponudb

    We are building a mobile EMI locker platform for phone retailers in India, similar to existing products like 101Locker, EMI Vault, and InstenLock. We need an experienced Android developer to build the customer-facing locker application. About the App: The app will be installed on customer phones at retail shops when they purchase phones on EMI. It must function as a Device Owner application with the ability to lock the device remotely if EMI payments are missed, and unlock automatically once payments are received. Required Technical Skills: Strong experience with Android Device Policy Manager (DevicePolicyManager) APIs Hands-on experience building Device Owner / DPC (Device Policy Controller) applications QR code-based provisioning during initial device setup DeviceAdminReceiver implement...

    €269 Average bid
    €269 Povprečna ponudba
    58 ponudb

    Hostaway and WPRentals API Integration for Holiday Let Management Site The project We need a developer to build a custom API integration between Hostaway (our channel manager) and our WPRentals website. The integration must allow guests to book directly on our site with payment, with Hostaway remaining the single source of truth for inventory, pricing, and availability. Required functionality 1. Property sync (Hostaway to WPRentals) - Pull all property listings from Hostaway via API - Sync property details, descriptions, amenities, images, and metadata into WPRentals - Auto-create new properties when added to Hostaway - Auto-update property content when changed in Hostaway - Auto-remove or deactivate properties when removed from Hostaway 2. Live availability and pricing - Real-time a...

    €194 Average bid
    €194 Povprečna ponudba
    253 ponudb
    REST API Tax Code Fetch
    3 dni left
    Verificirano

    I need a small, well-structured REST call that receives basic product details and a U.S. delivery address, then returns the correct sales-tax code in JSON. The third-party tax provider’s documentation and keys are already available; the job is to create the wrapper endpoint (or lightweight micro-service) that talks to that provider, forwards the request parameters, parses the response, and hands my application only the tax code we need. Key points • Data handled: product details supplied in the request body or query. • Action required: fetch the appropriate U.S. tax code from the existing tax API for the given destination. No create, update, or delete operations are needed. • Response format: strictly JSON. Deliverables 1. Clean, commented source (Node.js, ...

    €171 Average bid
    €171 Povprečna ponudba
    157 ponudb

    We are looking for a Python Developer to build and manage APIs, data processing, and KPI calculation logic for our system. The role focuses purely on backend development using Python, FastAPI, and MongoDB. Experience: 2–4 Years Location: Remote Key Responsibilities • Design and develop REST APIs using FastAPI • Handle request validation, error handling, and response structuring • Ensure APIs are scalable, secure, and well-structured • Implement KPI implementations including the calculations, formulas, and aggregations • Process structured data efficiently • Write optimized queries for performance • Assist in Integration of backend APIs with frontend systems • Handle data ingestion from external sources • Optimize API performance an...

    €230 Average bid
    €230 Povprečna ponudba
    32 ponudb
    AlipayHK Integration Expert Needed
    3 dni left
    Verificirano

    We are looking for an experienced developer who has hands-on experience with AlipayHK payment integration. Scope of Work: * Integrate AlipayHK payment gateway into our platform * Implement payment link generation via AlipayHK API * Handle callbacks/webhooks for payment success/failure/pending * Test end-to-end payment flow in sandbox/test environment * Deploy and verify on live environment Requirements: * Must have prior AlipayHK integration experience * Must share live project links or portfolio of previous AlipayHK work * Bids without proof of AlipayHK experience will be ignored * Knowledge of REST APIs and webhook handling * Add your stack experience (Node.js / Next etc.) Deliverables: * Working AlipayHK payment integration * Webhook/callback handler for payment status * Basic doc...

    €70 Average bid
    €70 Povprečna ponudba
    37 ponudb

    I need a lightweight, cross-platform mobile application built with Framework7 and Apache Cordova that lets staff scan Code 128 barcodes with the device camera, record those scans as raw-material movements, and instantly sync everything to a MySQL database running on (all devices sit on the same LAN). On first launch the app should present a username-and-password screen; once authenticated, users can open the scan view, point the camera, and have the barcode value, time stamp, and logged-in user written to the database through a REST endpoint. Please rely on a proven Cordova barcode-scanner plugin so no custom native code is required. Alongside the app I also need a small, web-based admin console. From any browser on the same network I should be able to • view real-time inventory ...

    €131 Average bid
    €131 Povprečna ponudba
    80 ponudb

    I’m building a premium, minimalist online store that will sell physical products across Latin America, so every detail has to feel native to Spanish- and Portuguese-speaking shoppers. The storefront should load fast, look clean on any device, and keep the focus squarely on the products. Key requirements – Language & currency: the whole journey must switch seamlessly between Spanish and Portuguese, with space for an optional English layer later on. – Payments: MercadoPago is the priority gateway; please wire it up for one-click checkout, refunds, instalments, and local tax handling. If the architecture makes it simple to add PagSeguro or PayU down the road, even better. – Tech stack: I’m open to either WooCommerce or Laravel with Filament. The decidi...

    €16 / hr Average bid
    €16 / hr Povprečna ponudba
    211 ponudb

    I’m looking to build a long-term collaboration with someone who can discuss architecture and trade-offs in clear, native-level English while turning ideas into production-ready web applications. The stack you’ll step into is centred on React.js for the front end and a mix of JavaScript/TypeScript services alongside Python micro-services on the back end. Day to day you’ll pick up features from our roadmap, shape the UX with React components, wire them to REST- or GraphQL-based endpoints, and help keep our automated tests green. I’ll count on you to suggest best practices, refactor when technical debt appears, and push code through pull-request review to staging and live. Because this is an ongoing partnership rather than a one-off gig, reliability and proactive c...

    €51 / hr Average bid
    €51 / hr Povprečna ponudba
    204 ponudb

    I’m building an Android-only music app where a listener can highlight any six-second to thirty-second slice of a song and instantly receive AI-driven suggestions that sound alike. The flow is deliberately simple: scrub the waveform, tap “Compare”, and a carousel of matches appears. Behind that single tap I want a content-based model that extracts timbre, tempo, key and mood vectors from the selected section, searches a local cache or cloud catalogue, then streams short previews for fast sampling. Here’s what I need from you: • A clickable Android prototype (Kotlin or Flutter are both fine) showing the waveform selector, “Compare” button, and a results view. No account system or playback rights management yet—just mocked audio files are enoug...

    €8 / hr Average bid
    €8 / hr Povprečna ponudba
    16 ponudb

    I’m putting together a lightweight shopping app in Flutter and would like your help bringing it to life. The core flow is straightforward: visitors create an account (email + password), browse a home screen that loads products from a REST API, tap through for full details, and add items to a cart. Everything should feel snappy, follow Material Design, and be organised under a clean architecture so future features slot in easily without performance hits. You’ll connect the UI to my REST endpoints, handle secure authentication, manage state cleanly, and wrap the whole experience in a modern look that matches Google’s Material guidelines. Smooth navigation, error handling, and responsive layouts for different phone sizes are important to me. Deliverables • Full Flutte...

    €455 Average bid
    €455 Povprečna ponudba
    273 ponudb

    I need a sharp-eyed manual tester to run our new REST API through its paces in Postman and confirm that it works exactly as designed. Your mission is pure functional testing—no load or regression work this time—so the goal is to prove that every call in the collection behaves correctly and fails gracefully when it should. Here’s what matters most to me: • Endpoint functionality: each URL must return the right status code and payload. • Data validation: responses must match the schema and respect field rules, including boundary values and required/optional attributes. • Error handling: bad inputs, missing tokens or malformed JSON should trigger the correct error codes and meaningful messages. You’ll get the Postman collection and enviornmen...

    €73 Average bid
    €73 Povprečna ponudba
    63 ponudb

    I need an experienced Salesforce Developer who can jump straight into Apex and LWC work while also taking charge of a series of REST-based integrations. Day-to-day you will be extending existing apps and building new ones, wiring them up to external services through well-designed, secure APIs. Your toolkit should naturally include VS Code, Salesforce CLI, and Git because that is exactly what I use to manage the org. You will spend most of your time writing efficient, bulk-safe Apex (async, triggers, controllers) and crafting responsive Lightning Web Components. Advanced Flow Builder configuration will round out many of the business processes we expose to users. Key areas you’ll tackle: • Build and enhance custom applications in Sales, Service, and Experience Cloud. • ...

    €18 / hr Average bid
    €18 / hr Povprečna ponudba
    154 ponudb
    Flight Booking implementation
    1 dan left
    Verificirano

    I already have a live PHP website, a fully-commented flight-booking codebase, and an active API token. What I now need is a seamless integration so visitors can interact with that engine on the front end. The job centres on three customer-facing actions: • Search flights • Book flights • View booking history Your mission is to wire the existing code into my back-end, expose the necessary endpoints, and then craft clean, responsive pages (HTML/CSS/JavaScript or a lightweight framework of your choice) that present those three functions clearly. Smooth session handling, error messaging, and a simple “My Trips” dashboard are essential. I value proven experience with PHP integrations, REST/JSON APIs, and payment/booking flows. If you’ve tackled airline ...

    €27 Average bid
    €27 Povprečna ponudba
    89 ponudb

    I am looking for an experienced developer to build a modern and responsive web application using React.js and related technologies. Requirements: - Develop a clean and responsive UI using React.js - Implement reusable components and maintain scalable architecture - Integrate REST APIs for dynamic content - Manage application state efficiently (Redux or Context API) - Ensure performance optimization and smooth user experience Optional Features: - User authentication (JWT or Supabase Auth) - Role-based access control - Dashboard or admin panel - Payment integration (Stripe or Razorpay) Preferred Tech Stack: - React.js, JavaScript / TypeScript - Tailwind CSS or modern CSS frameworks - Node.js, Express (if backend required) - MongoDB or Supabase Deliverables: - Clean and well-structured co...

    €46 / hr Average bid
    €46 / hr Povprečna ponudba
    89 ponudb

    I am building a full-scale accounting platform for shops and mid-sized companies and I want it engineered for longevity as well as everyday usability. The system must sit on a clean MVC architecture, so each layer can be swapped or extended without rewriting the whole stack. Core scope • Front-end: Flutter (mobile + web) with a slick, modern UI. • Back-end: ASP.NET (C#) REST APIs. • Database: SQL Server, structured for easy migration and future reporting needs. Essential features to ship in the first release • Invoicing and billing that handles VAT, discounts, returns, and printable PDF docs. • Expense tracking with category tagging and attachment upload. • Financial reporting (P&L, balance sheet, cash-flow) in both Arabic and English. &b...

    €1115 Average bid
    €1115 Povprečna ponudba
    159 ponudb

    The initial build of my app lives in Base 44, but it needs to grow up into fully released iOS and Android versions at the same pace. Most screens exist; what is missing is a solid backbone and the outside connections that make those screens actually useful. Here is where I need your expertise: • Re-create or export the existing Base 44 front-end so it runs smoothly on both Apple and Android devices. • Build out the backend—robust database management and well-structured REST/GraphQL APIs are the top priorities. • Wire up the third-party integrations that are already specced (payments, analytics, and one social login) so they work flawlessly across both platforms. Deliverables will be considered complete when: 1. Both iOS and Android builds pass TestFlight ...

    €16 / hr Average bid
    €16 / hr Povprečna ponudba
    276 ponudb

    Description:  We have an AI phone ordering system (Twilio + n8n + voice AI) that is about 80–90% complete. We need an experienced developer to step in and finish + fix the live call flow ASAP. Your job: Fix inbound call routing (Twilio → n8n) Ensure AI answers calls correctly Complete full flow: call → order → payment → confirmation Debug webhook / connection issues Make it stable and reliable Must have: Real experience with n8n Strong experience with Twilio Voice / webhooks API integrations (REST, webhooks) Experience building or fixing AI voice / call systems Goal: :point_right: Get ONE clean, working call loop live as fast as possible Notes: This is NOT a learning project — we need someone who has done this before Fast execution is more im...

    €16 / hr Average bid
    €16 / hr Povprečna ponudba
    111 ponudb

    I manage a fast-growing e-commerce business and I’m ready to add an experienced full-stack engineer to the team on an ongoing remote contract. The work centres on new feature development and optimisation across the entire stack: Python on the backend, React on the frontend. Day to day you’ll design and build REST APIs, craft responsive React components, and architect systems that stay fast and reliable at scale. Because we sell online, smooth integrations with payment gateways (think Stripe, Braintree, etc.) and headless CMS platforms are routine parts of the job, so depth in those areas is important. What I value most is clean, production-quality code, thoughtful pull requests, and clear English communication. We’re fully remote with flexible hours as long as there...

    €3232 Average bid
    €3232 Povprečna ponudba
    164 ponudb

    I need an experienced deep-learning engineer who can move fast to build a production-ready image-classification model. The system must take raw images, preprocess them, and reliably return the correct class label with clear confidence scores. Because I’m aiming for deployment straight away, please structure the code so I can drop it into a REST or gRPC service later. You are free to choose the framework you’re most comfortable with—TensorFlow, PyTorch, or another modern library—as long as the final solution is reproducible on a single high-end GPU. Expect to work with a labelled dataset of roughly 100k images; if additional augmentation or cleaning pipelines are needed, include them in your approach. Accuracy matters, but I’m also watching inference speed, so...

    €143 Average bid
    €143 Povprečna ponudba
    90 ponudb

    Saya baru memulai pengembangan sebuah aplikasi Android dan membutuhkan fondasi yang kokoh untuk fitur Login/Registrasi pengguna. Pada tahap awal ini fokusnya hanya di area autentikasi, jadi ruang lingkupnya tetap sederhana dan cepat diselesaikan. Yang saya perlukan: • Halaman registrasi dengan validasi e-mail dan kata sandi • Halaman login dengan proses autentikasi aman • Manajemen sesi sehingga pengguna tetap masuk setelah aplikasi dibuka kembali • Antarmuka dasar ber‐gaya Material Design yang mudah dikembangkan lebih lanjut Teknologi pendukung saya serahkan pada Anda. Jika terbiasa memakai Firebase Authentication, silakan. Bila lebih nyaman membangun REST API ringan dengan JWT, saya juga terbuka—yang penting sertakan dokumentasi pengaturan singkatnya...

    €355 Average bid
    €355 Povprečna ponudba
    44 ponudb

    I’m starting this project from a clean slate and need a full-stack developer who can deliver the first working version of a social media platform. The priority for this MVP is a solid user-profile system, so visitors must be able to register, create a profile, upload an avatar, edit their info, and manage basic privacy settings. A modular codebase is important because I may add a messaging system and an activity feed later; for now, those are out of scope. Please architect the project so these features can slot in without major refactoring. I’m open on the stack, but modern, well-supported tools such as React or Vue on the front end and Node.js, Laravel, or Django on the back end make the most sense to me. Clean REST (or GraphQL) APIs, PostgreSQL or MongoDB, and sensible au...

    €5 / hr Average bid
    €5 / hr Povprečna ponudba
    49 ponudb

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