Remote Senior TypeScript Backend Engineer | AI & LLM Focus

Darwin Recruitment; Warszawa; Remote; PLN 484,000 - 645,000; Full time

Job summary

Darwin Recruitment is seeking a freelance Senior TypeScript Backend Engineer to join a product development team on a 3-month contract, likely to extend. The role focuses on backend services, API design and AI-powered capabilities built on LLMs and agentive workflows.

You will independently design, build and iterate features end to end, with hands-on responsibility in a fast-paced, experimental product environment.

Qualifications

• Senior-level, hands-on TypeScript backend expertise (Node.js) with NestJS/Express/Fastify.
• Proven delivery of production-grade applications from concept to release.
• Strong API design and system integration experience.
• Ability to own features independently with minimal oversight.
• Working knowledge of LLMs and AI-powered applications.
• Familiarity with AI agent frameworks and orchestration patterns (advantageous).

Responsibilities

• Design, build and iterate on backend features end to end for the product initiative.
• Leverage AI-powered capabilities and LLMs within services.
• Collaborate with product development team to deliver production-ready software.

Skills

TypeScript Backend

Node.js

NestJS/Express/Fastify

API Design

AI/LLMs

Agentic AI

Independent Ownership

Job description

Darwin Recruitment is seeking a freelance Senior TypeScript Backend Engineer to join a product development team on a 3-month contract, likely to extend. The role focuses on backend services, API design and AI-powered capabilities built on LLMs and agentive workflows.

You will independently design, build and iterate features end to end, with hands-on responsibility in a fast-paced, experimental product environment.