Middle Full Stack Developer (Node.js/React)

About the Position

We are looking for a Middle Full Stack Developer (Node.js/React) to join our team at airSlate, a company dedicated to building pdfFiller, an online platform for creating, editing, and signing PDF documents. Join us as we continue to innovate and grow!

Responsibilities

• Own features end to end: From requirements to production and post-release monitoring of edge cases.
• Automated quality: Ensure the automated quality of what you ship, including unit and integration tests and eval cases for LLM behavior.
• Prompt regressions: Treat prompt regressions, evals, and non-determinism as everyday engineering concerns.
• Code review: Review code and documentation to keep the codebase consistent.
• Duty rotation: Take part in the duty rotation, monitoring production and responding to incidents.
• Process improvements: Propose improvements to processes, tooling, and legacy code as part of the team's ongoing modernization.

Requirements

• Experience with LangGraph or LangChain, agent orchestration, and state machines
• Experience with RAG and vector search (pgvector)
• Familiarity with SSE or other streaming protocols
• Experience with observability tools such as OpenTelemetry and the Grafana stack
• Experience with LLM evaluation, including eval datasets and LLM-as-judge
• Experience writing technical documentation (C4, ADR)

Nice to Have

• Experience with Node.js, TypeScript, NestJS, Vercel AI SDK, PostgreSQL, Drizzle ORM, Valkey, LiteLLM, Langfuse, OpenTelemetry, Zod, Jest, React, Webpack 5, yarn workspaces, Lerna, React Testing Library, Playwright, Docker, GitHub Actions, ECR, ArgoCD, Grafana, and AWS S3

We Offer

• Competitive salary
• Remote work options
• Educational budget
• Regular knowledge-sharing sessions
• Clear growth path

About the Company

We are a passionate and ambitious team of 120+ people building pdfFiller, an online platform for creating, editing, and signing PDF documents. pdfFiller empowers over 10 million users every month to create and edit PDFs, send them for signing, and securely store documents within a single application. Offering unlimited storage, unlimited templates, and cross-platform integration, pdfFiller is the only PDF editor needed to get your document done.

And now, we are looking for a Full Stack Developer who is prepared to contribute to the next chapter of our company's growth. The team builds an AI assistant that understands users' documents and acts on them, an MCP server that exposes pdfFiller's capabilities to external AI clients, and AI-powered improvements to existing product features. Our engineers propose improvements rather than just execute tickets, and our roadmap is planned a year ahead but stays flexible.