React Query Jobs in Andover, MA (NOW HIRING)

Ark is building the world’s highest-fidelity bioprocess simulation software to help life‑saving therapies reach patients faster. By democratizing complex AI and multi‑physics models in an intuitive software interface, we are ushering in a new era of digital bioprocessing.

With Ark, scientists can replace weeks‑long, costly ($10K–$1M+) bioreactor experiments with simulations that run in seconds. This enables researchers to explore thousands more scenarios, accelerate time to market, and ensure more medical breakthroughs make it from the lab to the world.

Ark is seeking a Fullstack Software Engineer to join our fast‑moving startup tackling some of the hardest problems in biomanufacturing. In this role, you’ll build end‑to‑end product experiences across the frontend and backend that power our digital bioprocess platform. You’ll work on performant, beautiful, and intuitive interfaces and the APIs, data models, and services that support high‑fidelity bioprocess simulations. You’ll collaborate closely with designers, engineers, and bioprocess modelers to bring complex scientific workflows to life—from browser to API to database. This is an opportunity to contribute to core product architecture and help shape the way scientists interact with high‑fidelity bioprocess simulations.

• Fullstack product development – Build and ship end‑to‑end features spanning UI, APIs, and data layers.
• Frontend development – Build responsive, high‑performance SPAs using React (or Vue) and TypeScript.
• Data fetching & caching – Implement robust server‑state management with React Query (TanStack Query), including caching, invalidation, optimistic updates, and pagination for scientific workflows.
• Auto‑generated API clients – Collaborate with backend engineers to produce and consume auto‑generated, type‑safe API clients from OpenAPI specs (or shared schemas), ensuring frontend/backend contracts stay aligned.
• Backend development – Design and implement services and APIs in Python (FastAPI), integrating with Postgres and compute workloads.
• Schema‑first integration – Use OpenAPI / JSON Schema and validation tooling (e.g., zod) to support safe, consistent communication and shared types across the stack.
• Performance & UX optimization – Ensure smooth rendering and intuitive interactions for complex visualization and simulation tools, while keeping API endpoints fast and reliable.
• Code quality & testing – Write modular, well‑tested, and documented code across the stack in a collaborative Git workflow.
• Cross‑functional collaboration – Partner with modelers, designers, and engineers to deliver cohesive, production‑ready product features.

• Frontend: TypeScript, React, Tailwind, React Query (TanStack Query)
• API Integration: OpenAPI‑generated clients, JSON Schema, zod (or equivalent runtime validation)
• Backend: Python (FastAPI), Postgres
• Infrastructure: Docker, AWS (or similar cloud platform)

2–5 years of professional experience in software development, with meaningful work across frontend and backend. Strong proficiency with TypeScript and a modern UI framework (ideally React). Hands‑on experience with React Query / TanStack Query (or equivalent) for server‑state management—caching, invalidation, background refresh, and async workflows. Experience generating and using typed API clients from OpenAPI (or similar schema‑first approaches) in production. Backend experience in Python/FastAPI (or similar) and building reliable, well‑structured REST APIs.

• Comfort with relational data modeling and working with Postgres (migrations, query patterns, performance basics).
• Strong sense of code quality, modular design, and testing practices across the stack.
• Bonus: Experience with monorepos/type‑sharing, Docker workflows, CI/CD, AWS, or 3D/visualization frameworks.

• Full‑time, exempt
• Location: Cambridge, MA
• Benefits: Health, dental, and vision coverage, holiday and vacation time, 401k matching, stock options, and career growth opportunities

Ark