Senior Software Engineer (AI & ML)

Department: Data & AI

Employment Type: Permanent - Full Time

Location: London, United Kingdom, UK - London, Hybrid

About the role

• Design, build and run production AI agents that automate multi-step underwriting decisions over unstructured data. 
• Build the agent runtime, including orchestration, durable state, retries and long-running workflows that recover cleanly from failure. 
• Develop the tools, APIs and data services that agents call, creating clear contracts, predictable failure modes and full auditability. 
• Engineer guardrails, human-in-the-loop checkpoints and fallbacks for high-stakes automated decisions. 
• Instrument, monitor and troubleshoot agents and services in production, including tracing, cost, latency and decision logs, working with ML engineers to turn those insights into evaluations and improvements. 
• Help drive system design and architectural decisions for our agents and the services around them. 
• Design and evolve the data models and database schemas supporting submissions, agent runs, decisions and audit trails. 
• Provision and manage cloud infrastructure through Terraform and contribute to a high production standard across agent-generated code and tests.
• Work closely with business, product and engineering teams to set delivery cadence, manage expectations and make pragmatic decisions about where additional engineering quality adds the most value. 
• Support the development of other engineers through code reviews, best-practice guidance and knowledge sharing

About you

• Hands-on experience building LLM-based agents or agentic systems in production, ideally using orchestration frameworks such as LangGraph or LangChain, or equivalent systems you’ve built yourself. 
• A strong understanding of how agents fail in the real world, from non-determinism and tool failures to runaway loops, cost and latency issues, and how to engineer around them. 
• 5+ years’ professional software development experience in Python or another backend language such as Go, Java or C#. Our stack is Python, so you’ll need enough working knowledge to transfer your skills quickly if it isn’t already your main language. 
• Strong experience with asynchronous and concurrent programming, alongside a rigorous approach to unit and integration testing.
• Day-to-day experience delivering software with AI coding agents, while maintaining a high bar for the code they produce. 
• Experience designing systems end to end, including service boundaries, data flows and failure modes, with the judgement to make and explain architectural trade-offs. 
• Strong relational database and data modelling experience. We use PostgreSQL, covering areas including schema design, query performance, transactions, concurrency and safe schema migrations. 
• Experience building distributed, asynchronous microservices using message brokers such as Azure Service Bus, with an understanding of at-least-once delivery, idempotency and dead-letter handling. 
• Experience building clear, well-documented RESTful APIs. We use FastAPI.
• Strong cloud and infrastructure-as-code experience. Our environment uses Azure and Terraform, and hands-on IaC experience is essential for this role. 
• Experience with Docker and production container platforms such as Azure Container Apps, Kubernetes, GKE or ECS, alongside CI/CD workflows and YAML pipeline definitions. 
• Clear communication, pragmatic judgement and the confidence to work independently, influence technical decisions and mentor other engineers.

Core Values