Middle Fullstack Developer (Node.js/React)

Location: Remote from Poland

Company

hirify.global develops pdfFiller, an online platform for creating, editing, signing, and securely storing PDF documents used by more than 10 million people each month.

What you will do

• Build tool-calling, streaming, and RAG features for an AI assistant and an MCP server.
• Own features end to end, from requirements and acceptance criteria through production release and post-release monitoring.
• Develop and maintain automated quality coverage, including unit tests, integration tests, and LLM evaluation cases.
• Review code and documentation, and propose improvements to processes, tooling, and legacy code.
• Monitor production systems and respond to incidents through the duty rotation.
• Work across backend and frontend systems, with an approximate focus of 80% backend and 20% frontend.

Requirements

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

Culture & Benefits

• Work remotely from Poland as part of a 120+ person pdfFiller team.
• Contribute ideas and propose improvements rather than only executing predefined tickets.
• Access an educational budget and regular knowledge-sharing sessions.
• Follow a clear professional growth path.
• Work with a roadmap planned a year ahead while retaining flexibility.