Lead Platform Engineer

La Fosse; Greater London; On-site; GBP 96,000 - 160,000; Full time

Job summary

La Fosse is seeking a Lead Software Engineer (backend and AI focus) in London. The role centers on building scalable Node.js backends and AI-enabled features, with hands-on leadership in a fast-moving startup environment.

You will collaborate with the Head of Engineering to define technical strategy and architecture, while shaping AI-driven products and workflows. The ideal candidate has deep Node.js/TypeScript experience, a passion for AI, and comfort working across Python-driven AI

Qualifications

• Strong commercial experience with Node.js, TypeScript, NestJS, REST APIs and distributed systems.
• Experience building products in startups, scale-ups or high-growth technology businesses.
• Hands-on experience with Python and an interest in Generative AI, LLMs, AI Agents, AI Automation.
• Experience integrating with models such as OpenAI, Anthropic Claude, Gemini or open-source LLMs.
• Strong understanding of system design, microservices, event-driven architecture and cloud-native development.

Responsibilities

• Building and scaling backend services using Node.js and TypeScript.
• Developing AI-powered features, agentic workflows, and automation tools.
• Working closely with engineering leadership on technical strategy and architecture.
• Using Python to support AI, data, and machine learning initiatives.
• Taking products from idea through to production in a high-ownership environment.
• Helping shape engineering best practices in an AI-first business.
• Managing a small engineering team.

Skills

Node.js

TypeScript

NestJS

REST APIs

Distributed systems

Tools

PostgreSQL

MongoDB

Vector Databases

Job description

Lead Software Engineer (backend and AI focusses) - Up to £160k - London

We're partnering with a venture-backed AI startup building an AI-native platform that combines automation, voice AI, and agentic workflows to solve complex real-world operational problems. Engineering sits at the heart of the business, with AI embedded into both the product and the way the team builds software.

As a Lead Software Engineer, you'll work directly with the Head of Engineering in a highly impactful, hands-on role. This is a fast-moving startup environment where adaptability is key. The focus is primarily Node.js, with Python used across AI initiatives, automation, and LLM-powered features. Open to moving into more senior postions as the team grows!

What you'll be doing

• Building and scaling backend services using Node.js and TypeScript.
• Developing AI-powered features, agentic workflows, and automation tools.
• Working closely with engineering leadership on technical strategy and architecture.
• Using Python to support AI, data, and machine learning initiatives.
• Taking products from idea through to production in a high-ownership environment.
• Helping shape engineering best practices in an AI-first business.
• Managing a small engineering team.

What we're looking for

• Strong commercial experience with Node.js, TypeScript, NestJS, REST APIs and distributed systems.
• Experience building products in startups, scale-ups or high-growth technology businesses.
• Hands-on experience with Python and an interest in Generative AI, LLMs, AI Agents, Agentic Workflows, Retrieval-Augmented Generation (RAG), Prompt Engineering and AI Automation.
• Experience integrating with models such as OpenAI, Anthropic Claude, Gemini or open-source LLMs.
• Strong understanding of system design, microservices, event-driven architecture and cloud-native development.
• Experience working with PostgreSQL, MongoDB, Vector Databases (Qdrant, Pinecone, Weaviate or similar).
• Comfortable working in ambiguous environments where priorities evolve quickly.
• Product-minded engineer who wants to own outcomes, not just tickets.

Nice to have

• Experience with AI products, agents, or LLM integrations.
• Knowledge of cloud infrastructure, microservices, and event-driven systems.
• Exposure to NestJS, Next.js, or modern frontend technologies.
• Previous experience in a venture-backed startup.

Lead Software Engineer (backend and AI focusses) - Up to £160k - London