A fast‑growing Series A AI start‑up is building production‑grade AI systems for UK financial services are hiring a Lead Software Engineer (Node.js) to set technical direction, own architecture, and lead hands‑on delivery of AI‑powered products.
This is a senior individual contributor role (no management) - You’ll act as the technical co‑lead alongside an Engineering Manager, owning engineering quality, architectural decisions, and complex problem‑solving in a regulated environment.
There is tons of autonomy and a real chance for you to really make a big impact and put your mark on the product & culture!
They received Series A funding and are scaling quite heavily as a business to continue to grow their product line (team size is 100)
What you’ll do
* Own technical direction for your squad: architecture, ADRs, standards, and technical risk
* Design and deliver LLM‑powered features: workflows, RAG pipelines, prompt engineering, and agentic execution
* Lead adoption of an AI & Agentic Platform (LLM routing, guardrails, observability, evaluation)
* Build and ship production‑grade Node.js services on AWS (serverless, Lambda, DynamoDB, event‑driven systems)
* Set the quality bar: code reviews, test coverage, security‑by‑design, performance, reliability
* Influence cross‑squad architecture and contribute to architecture review governance
* Champion compliant‑by‑design engineering in an FCA‑regulated context (auditability, traceability)
What they’re looking for
* 10+ years of software engineering experience, including 3+ years in production AI systems
* Strong Node.js expertise (this role is Node‑first)
* Hands‑on experience with LLMs: prompt engineering, RAG, evaluation, agentic patterns
* Cloud‑native AWS experience (Lambda, DynamoDB, S3, event‑driven architectures)
* Proven ability to set technical direction, mentor engineers, and influence architecture beyond your team
* Strong written communication: clear ADRs and design documentation
Nice to have
* Background in FinTech or regulated financial services
* Experience with model routing / abstraction layers
* AI observability: cost monitoring, drift detection, safety evaluation
* Familiarity with ISO 27001 / SOC 2 or compliance‑heavy environments
Why this role
* Real AI in production
* High‑impact technical ownership in a scaling AI start‑up
* Fully remote, UK‑based role
* Complex, meaningful problems at the intersection of AI, software engineering, and regulation