Senior Full Stack Engineer (back-end) | Outside IR35 | Hybrid

Senior Fullstack Engineer

£450-550 per day

6 months

Outside IR35

Hybrid - 2 days per week on site (London)

We're supporting a high-growth, AI-driven product business building a scalable platform from the ground up. They operate as a small, high-calibre team with high standards, low bureaucracy, and real ownership. They're looking for a Senior Fullstack Engineer (Back End leaning) to take responsibility for core Back End systems and help shape product direction in fast-moving environment.

This is a role for someone who is comfortable building without perfect specs and takes initiative naturally.

Requirements

Strong Node.js and GraphQL (NestJS) experience

PostgreSQL, Prisma, and solid data structures/OOP fundamentals

Experience building high-concurrency, event-driven systems

GCP experience (Terraform desirable)

Experience working with AI/LLMs in production environments

Strong focus on system reliability (monitoring, alerting, logging, testing, incident-aware design)

Demonstrated ownership of features or systems end-to-end, with the ability to operate independently

Comfortable making progress in environments with evolving or incomplete requirements

Pragmatic approach to delivery - able to balance speed with long-term maintainability

Proven ability to operate effectively under pressure or shifting priorities

Ideally has built, launched, or scaled a product, startup, or meaningful side project