Payroll API Integrations - iSolved - TypeScript Developer - (Remote - US Based)

Description: We're looking for a detail-oriented developer to build payroll provider integrations on an established TypeScript backend. Someone I can hand a scope to, who delivers results, communicates any API frictions, and solves them without hand-holding. Your first project will be a new payroll provider: isolved. You'll get a stripped-down clone of our payroll engine and deliver a working integration against it. This gives you a realistic scope with our actual patterns, and gives us a clear picture of how you work. About the work The hard part is done. We have a working integration platform with several payroll providers already in production with a proven pattern for adding new ones. We need someone who can own new integrations end to end as well as maintain existing integrations. Navigate the nuances of each provider's API, handling auth and rate limits, writing and running tests, and delivering functioning, production-ready code. The initial project is API work, primarily backend, but we also have full-stack needs down the road, so frontend experience (React/TypeScript) is a plus. Our stack TypeScript / Node.js (Express) PostgreSQL with Drizzle ORM Vitest, including live integration test suites against each provider REST APIs, Redis, AWS S3, Auth0, Git How we work We use Claude Code as our primary development tool and suggest you do the same, though we're open to any secure coding agent. You should be comfortable working with AI coding tools daily while still owning the quality of what ships: reading the code, understanding the APIs, and verifying behavior with tests. AI-assisted is fine; AI-unsupervised is not. Requirements -Strong TypeScript/Node.js backend experience, or many years in a comparable language -Hands-on experience integrating third-party APIs, ideally payroll or HR platforms -Disciplined about testing and verifying edge cases -Comfortable with AI coding agents (Claude Code preferred) -Detail-oriented and trustworthy with sensitive data - this is payroll, accuracy matters In your proposal, please include: -Which payroll or HR platforms you've integrated with (ADP, Paychex, Paylocity, Gusto, UKG, isolved, etc.) and what the integration did -Which coding agent you use and how it fits into your workflow -A brief example of a tricky third-party API issue you debugged and how you resolved it