Experienced WordPress Plugin Developer for a Custom API Access Plugin

After read my doc, please tell me your budget in your first sentence. We are looking for an experienced WordPress plugin developer with good work ethic and enthusiasm about getting the job done. Our business is to process data files submitted by customers and produce reports based on that data. The actual data processing is done by a third party that we access via API for which we need this plugin. Note that this job is just for the plugin. We are not looking to custom code the entire site and are going to use existing WordPress templates and plugins as much as possible. The custom plugin should be able to interact with those. SUMMARY Customer registers on our site, pays, uploads a raw data file, then the PLUGIN takes the file, submits it via API for processing, receives processed data and creates a PDF document from the processed data. PLUGIN FEATURES - Take a text file uploaded by the customer that contains certain raw data - Authenticate with third party API, submit the raw data file along with processing options based on the product selected by customer - Receive processed file fetched by the third party API in text / html format - Create a PDF report according to a template filling it with the received processed data. We have a PDF template design but you’ll need to implement it to create actual PDFs. - Assign the PDF file to the customer to be accessible only from customer’s account - Provide security features to prevent unauthorized access to customer data (to be discussed) On the admin, side, the plugin should - Allow administrators to see and amend the entire list of available options for processing customer data file to stay up-to-date with the changes our third party processor makes in their service. - Have the ability to create custom option packages that could be purchased by customers as products. - Some option packages will be on open display on the site as individual products and some available only after entering a custom code - Other features related to administrative functions such as history of transactions - nothing super complicated. PLUGIN’s PLACE IN WORKFLOW - Customer visits the site and decides to purchase a service/digital product - Customer chooses a specific service package - Customer registers an account (or uses an existing account) and uploads a text file with data. (MemberPress or similar) - Customer pays for the selected service package (via a shopping cart plugin, WooCommerce, etc.) PLUGIN recognizes payment and the package purchased and makes API calls as above - Customer receives a PDF file in his/her account ready for download PLUGIN then deletes the original customer data file (but keeps the processed PDF in customer account until customer deletes it) The budget for this project is to be determined during the discussions with developer (you). So the current figure here is just a placeholder.