Lead Platform Engineer

Nextech; Sefton; Hybrid; GBP 140,000 - 160,000; Full time

Job summary

Agentic AI in London is seeking a Lead Platform Engineer to own the build across our stack. This player-coach role is 80% hands-on backend work and reports directly to the Head of Engineering; you’ll set the technical bar and drive delivery while still writing code.

You’ll lead a small team, shape microservice and event-driven architecture, and design scalable backend systems. You’ll collaborate with remote engineers in India, work with Claude Code and agentic workflows, and contribute to

Qualifications

• 5-8+ years hands-on engineering in AI, SaaS, or automation platforms.
• First-class or strong degree in CS, Engineering, Maths, or related.
• Already a lead engineer or ready to own more.
• Deep Node.js/NestJS expertise; REST API and microservices; Next.js bonus.
• Hands-on experience with LLMs and agentic workflows; Claude Code use daily.
• Startup DNA or top-firm performer; comfortable making strong calls.
• Desire to own hard problems and lead a small team while building.
• Able to lead engineers while remaining the strongest builder in the room.

Responsibilities

• Architect, design, and build scalable backend systems and APIs end to end.
• Design microservice and event-driven architectures for real-time workflows.
• Lead a small team, drive delivery, review work, own what ships.
• Set the standard for agentic AI development and Claude Code workflows.
• Shape technical strategy directly with the Head of Engineering.
• Maintain secure, performant systems and data pipelines as we scale.
• Get close to the product and understand workflows being automated.

Skills

Node.js

NestJS

REST API

Microservices

Next.js

LLMs

Agentic workflows

Team leadership

Startup experience

Ownership

Education

CS/Engineering/Math degree

Tools

Google Cloud

Kubernetes

PostgreSQL

MongoDB

Qdrant

Job description

Lead Platform Engineer

London (Hybrid) | Full-time, Permanent | Up to £160K + equity

We're a fast-growing AI company in London looking for a Lead Platform Engineer to work under our Head of Engineering and own the build across our stack, a great engineer first, the person who builds the hardest things and sets the technical bar.

You'll be number two to the Head of Engineering, and about 80% hands-on backend. This is a player-coach role, not an engineering manager one. You lead through technical credibility, set the standards, and own delivery without stepping away from code. You'll also help manage remote engineers in India working UK hours.

Agentic AI is core to how we operate: our engineers work alongside Claude Code and AI agents every day, and the product itself runs on agentic pipelines. You need to be native to Claude Code and agentic engineering, not an occasional user of AI coding assistants, and ahead of the curve here, raising the standard for how we build with AI.

What you'll do

• Architect, design, and build scalable backend systems and APIs end to end
• Design microservice and event-driven architectures for real-time operational workflows
• Lead a small team, drive delivery, review work, own what ships
• Set the standard for agentic AI development, from Claude Code workflows to team-wide patterns
• Shape technical strategy directly with the Head of Engineering
• Maintain secure, performant, reliable systems and data pipelines as we scale
• Get close to the product, understand the workflows you're automating

Requirements:

• 5-8+ years' hands-on engineering, ideally AI, SaaS, or automation platforms
• A first-class or strong degree in CS, Engineering, Maths, or related
• Already a lead engineer, or nearly there, ready to own more
• Deep Node.js/NestJS expertise; strong REST API and microservices experience; Next.js a bonus
• Real, hands-on experience building with LLMs and agents, you use Claude Code and agentic workflows daily, not as novelties
• Startup DNA (or standout performer at a top firm), comfortable making the right call without a committee
• Hungry for ownership over a hard problem and a small team, not a comfortable seat in a big org
• Able to lead engineers while still being the strongest builder in the room

Not for you if: you want a 9-5 in a big firm with an established playbook, a pure people-management track, or months of ramp time, or if you see AI coding tools as optional extras.

The stack: NestJS + Next.js, monorepo deployed into microservices, Google Cloud + Kubernetes, Postgres/MongoDB/Qdrant. Built to run agents, not just respond to them.

The deal: Permanent, full-time, hybrid, up to £160K + equity, real ownership from day one, direct access to founders.

Why this role:

By month six, you're the go-to for the hardest problems in the business. By month twelve, a meaningful part of the architecture, and the team is yours. If you want to build and lead from day one, this is it.