API Developer Needed for Endpoint Development in Startup Environment

Are you a backend engineer who enjoys debugging, improving existing systems, and completing real product features in a fast-moving startup environment? We are building a platform for the foodservice industry focused on bid management, rebates, contracts, invoices, and document automation. We are looking for a backend developer to help us fix, complete, and stabilize several important modules in our application. This will begin as a paid trial project. If the work is completed successfully, there is an opportunity for ongoing development work as we continue to grow. Main Tasks We currently have several backend modules already built, but they are incomplete, buggy, or not working as expected. Your main responsibility will be to review the existing code, identify issues, fix bugs, complete missing functionality, and make sure the modules work properly from end to end. 1. Invoice Management Module We currently have an invoice module, but it is not working as expected and has multiple bugs. This module also connects with Stripe, so we need someone who can troubleshoot and complete the Stripe-related backend workflows. Responsibilities may include: Debugging the existing invoice management module Fixing invoice creation, updating, viewing, and status logic Reviewing and fixing Stripe integration issues Ensuring invoice/payment data is handled correctly Improving API reliability, validation, and error handling Testing the full invoice workflow from admin and user perspectives 2. Contracts Module We currently have a contracts module, but it is not fully functional. At the moment, admins are not able to properly create contracts, and users are not able to view or sign open contracts. This module uses DocuSign, so experience with DocuSign or similar e-signature integrations is strongly preferred. Responsibilities may include: Debugging the existing contracts module Fixing admin contract creation workflows Fixing user contract viewing and signing workflows Reviewing and fixing DocuSign integration issues Ensuring contract statuses update correctly Handling permissions and access control for admins and users Testing the complete contract lifecycle from creation to signature 3. Document Classifier Module We have a document classifier module that works in some cases, but it fails when multiple files are loaded through S3 and has additional bugs. We need help stabilizing the file processing and information extraction workflow. Responsibilities may include: Debugging the existing document classifier module Fixing issues with multiple file uploads through S3 Improving information extraction reliability Handling batch file processing correctly Fixing bugs related to file parsing, storage, and classification Improving error handling and logging for failed document processing Testing single-file and multi-file workflows What You’ll Do You will be working primarily on backend development and debugging for an existing application. This is not just new feature development — we need someone comfortable jumping into existing code, understanding how the system works, finding bugs, and completing unfinished backend workflows. Your work may include: Reviewing and debugging existing Nest.js/TypeScript backend code Building and fixing RESTful API endpoints Working with Stripe, DocuSign, S3, and document-processing workflows Improving validation, permissions, error handling, and logging Testing APIs using Postman or similar tools Coordinating with frontend developers to ensure features work end to end Creating or updating backend/API documentation as needed Using Git and our CI/CD workflow for deployment Tech Stack Our current backend stack includes: Nest.js TypeScript REST APIs Stripe integration DocuSign integration S3 file storage Document classification / extraction workflows CI/CD pipelines Postman or similar API testing tools Slack and ClickUp for communication and task tracking Skills We’re Looking For The ideal candidate should have: Strong experience with Nest.js and TypeScript Experience debugging and completing existing backend modules Strong understanding of RESTful API design Experience with third-party API integrations Experience with Stripe is strongly preferred Experience with DocuSign is strongly preferred Experience with S3 or cloud file storage is preferred Ability to troubleshoot complex backend bugs Strong API testing skills using Postman or similar tools Good understanding of authentication, authorization, and permissions Ability to write clean, maintainable code Clear communication and reliable follow-through Comfort working in an agile startup environment Compensation and Trial Period This role will start with a paid trial sprint. Compensation is $100 per completed 2-week sprint, paid after successful completion, testing, and verification of the assigned sprint work. We understand this is modest starting compensation, but we are looking for someone who wants to grow with the company. If the initial work is completed successfully, we would like to continue working together on additional backend features, improvements, and platform modules. There may also be an opportunity for full time employment consideration after a successful trial period, based on performance, reliability, and long-term fit. Why Join Us? Meaningful Product Work Your work will directly improve core parts of our platform, including invoices, contracts, payments, and document automation. Startup Growth Opportunity We are an early-stage company building in the foodservice bid and rebate space. The right person can grow with us as the platform expands. Real Ownership You will not just be assigned small isolated tasks. You will help complete important backend modules that are central to the product. Flexible Collaboration We use Slack and ClickUp to manage tasks and communication. Standups may be scheduled as needed, and we work in an agile sprint-based structure. How to Apply Please apply with: A brief summary of your backend experience Your experience with Nest.js and TypeScript Any experience with Stripe, DocuSign, S3, or document processing Examples of backend modules or integrations you have built or fixed Your availability for a 2-week sprint Confirmation that you are comfortable working on a paid trial sprint with the possibility of ongoing work We are looking for someone who can start by helping us fix and complete the invoice, contracts, and document classifier modules. If the work goes well, we would like to hire you for additional backend development work as we continue building the platform.