Senior FastAPI Developer

Newcode.ai; New York (NY); On-site; USD 140,000 - 210,000; Full time

Benefits offered by this job

Flexible, English-speaking environment

Collaborative, high-energy team

Job summary

Newcode.ai is building AI tools for professional services. You will own the backend behind AI features, including APIs, data pipelines, and orchestration between our product and language models.

You’ll design retrieval over large document sets, ensure dependable LLM interactions, and stream results to the UI at production scale. The role emphasizes robust architecture decisions, fast, secure processing of confidential data, and ownership of long-running jobs.

Qualifications

• Requires 7+ years building production backend systems.
• Focus on reliability, scalability, and security for confidential data.
• Experience with LLM-powered systems, RAG, tool-calling, and agents is a plus.
• Proficient in Python and FastAPI development stack.
• Familiarity with distributed systems and async processing.

Responsibilities

• Design and build APIs and services powering products.
• Work on AI plumbing: retrieval, orchestration, tool-calling, streaming responses.
• Ensure reliability of async and distributed tasks: ingestion, embeddings, long jobs on Redis.
• Integrate with systems clients use (email, document stores) and ensure load handling.
• Prioritize data security and isolation in production.

Skills

Python

FastAPI

PostgreSQL/SQL

Redis

LangChain

LlamaIndex

Tools

LangChain

LlamaIndex

Job description

Who are we?

We build AI tools for firms in legal and professional services: software people use for real work, not demos. We started a few months ago and already have paying clients who rely on what we ship. The team is small and moving fast.

The role

You'll own the backend behind our AI features. That's the APIs, the data pipelines, and the orchestration sitting between our product and the language models doing the work. In practice it means running retrieval over large sets of documents, getting dependable results out of LLMs and their tool calls, streaming responses to the UI, and processing long jobs in the background without things falling over.

Itisn'tCRUD work. The hard parts here are keeping AI systemsaccurateand fast with confidential data, at production scale.You’llmake architecture calls early and live with them.

What You'll Do

• Designing and building the APIs and services our products run on.
• Working on the AI plumbing: retrieval, orchestration, tool-calling, response streaming, and the evals that tell us whether the output is any good.
• Keeping async and distributed work reliable: document ingestion, embeddings, and long-running jobs onRedis.
• Building integrations with the systems clients already use, like email and document stores, and making them hold up under load.
• Taking data security and isolationseriously, sinceclients hand us confidential material.

Who You Are

• At least seven years building backend systems that run in production. Depth matters more to us than the number.
• You think about how things fail, not just how they behave wheneverything'sfine.
• You'vebuilt real LLM-powered systems, oryou’reitching to: RAG, tool-calling, agents. You know where they tend to break.
• You use AI coding tools (Claude Code, Cursor, Copilot) and use them well. Faster output, but you understand and stand behind every line; you'dapprove sloppy AI-written code in review, so you don'tship it either.
• You're refine in a startup that changes direction. Decisions get made, then revisited.

Experience we expect with the stack:

• Python: 6+ years
• FastAPI: 3+ years
• PostgreSQL / SQL
• Redis: 2+ years

Nice to have: RAG or vector search experience;LangChainorLlamaIndex; streaming over SSE, WebSocket orSignalR; Microsoft Graph and email integration work.

Why Join Us?

• Be a driver of innovationin one of Oslo's most exciting AI ventures
• Work with talented peersin a collaborative, high-energy team
• Shape both product and cultureas we grow
• Flexible, English-speaking environment