Senior JavaScript Engineer

Job description

Senior JavaScript Engineer (Full Stack) | FinTech Platform | London Hybrid | £85,000

We’re working with a London-based Fintech company who are building high-performance trading/finance systems for enterprise clients.

This is a long-term, production-critical platform that is actively evolving, with a strong focus on performance, reliability, and clean engineering. You’ll be joining a genuinely senior team where ownership is expected and good engineering is the baseline.

Role:

You’ll take end-to-end ownership of features across a complex internal trading platform, working across the full stack with modern TypeScript tooling.

This is not a ticket-taking role. You’ll be involved in shaping solutions, working directly with stakeholders, and contributing to how the system evolves.

Responsibilities:

• Building and maintaining full-stack features using TypeScript, Node.js and React
• Working on real-time systems using WebSockets, Redis and SQL
• Driving high-quality engineering through automated testing (Jest, Playwright)
• Collaborating closely with DevOps on observability, pipelines and system performance
• Taking ownership from design through to production
• Contributing to code reviews and raising the overall engineering bar
• Using AI-assisted development tools as part of day-to-day workflow

Qualifications:

• 7+ years of software engineering experience
• Strong TypeScript experience across both backend and frontend (Node.js + React)
• Experience building and maintaining production-grade systems
• Comfortable operating in a senior, autonomous environments
• Strong communication skills and ability to work directly with stakeholders

If this sounds like a fit, please apply with your latest CV and we’ll be in touch.

Thanks,

Chloe

Extra information

Status

Open

Education Level

Secondary School

Location

City of London

Type of Contract

Full-time jobs

Published at

21-03-2026

Profession type

Accountancy

Full UK/EU driving license preferred

No

Car Preferred

No

Must be eligible to work in the EU

No

Cover Letter Required

No

Languages

English