Senior Software Engineer (Expansion) in London

Requirements

• Expert proficiency in TypeScript, comfortable working in a large monorepo and across multiple services
• Expert-level experience in designing and operating event-driven backend systems on AWS (e.g. Lambda, EventBridge, SQS, API Gateway), including thinking through eventual consistency, retries, and idempotency
• Proven hands-on experience with CQRS, event sourcing, projections, and Hexagonal / Clean Architecture style codebases
• Exposure to a modern frontend framework like React
• Experience working with React, with the ability to build and extend internal-facing UIs that sit on top of complex domain models
• Experience modelling complex business domains where rules and configuration evolve frequently
• Familiarity with CI/CD workflows (GitHub Actions) and automated testing across unit, integration, and end-to-end layers
• Exposure to monitoring and observability tooling such as DataDog
• Any prior exposure to insurance, fintech, or other regulated, transactional domains is welcome but not required

What the job involves

Join Flock as a Fullstack Engineer within our Expansion Team, where you'll play a pivotal role in building the platform that brings new fleets, new brokers, and entirely new sectors onto Flock.

What we think is most exciting about the role

• Drive Architectural Consistency: You will drive consistency across our systems by diving deep into complex backend architectures and understanding core principles. As we expand into new sectors, your ability to master and enforce architectural patterns will directly shape the stability and scalability of how thousands of vehicles are quoted and brought on cover.
• Work at the Intersection of Data and UX: Partner closely with underwriters, pricing engineers and product managers to transform complex submission data and rating logic into intuitive, performant interfaces. You'll be a key bridge between Flock's underwriting engine and the broker and fleet customers who rely on it every day.
• Modern AWS-Driven Stack: Leverage AWS services like Lambda, API Gateway, and EventBridge to build scalable, event-driven systems that power our quote-to-bind pipeline. While this is a full-stack role, you'll have ample opportunity to expand and apply your AWS knowledge in a production environment.
• Ownership and Autonomy: You'll own the delivery of features from ideation to deployment. Your work will have a direct and visible impact on how Flock wins new business, how brokers experience our platform, and how quickly we can open up entirely new lines of cover.

A little more on what you'll be doing

As a Senior Engineer at Flock you will own problems end to end, from design and build to deployment and measuring impact, working with engineers to keep our codebase clean and maintainable.

• Microservices & Event-Driven Backend Engineering: Build and evolve services in a TypeScript monorepo organised around CQRS and Hexagonal architecture, with clear separation between domain, application, and infrastructure layers. Design commands, events, and projections that let our services communicate asynchronously and stay decoupled as the product surface grows. Work across a broad domain like pricing, underwriting, brokers, customers, vehicles, invoices, finance and more.
• Product Config Front-End: Develop and extend our internal Product Config UI in React (TypeScript), the tool we use to define new products, configure rating and underwriting behaviour, and onboard new customers, businesses and sectors onto the platform. Turn complex, schema-driven configuration into interfaces that underwriters and product managers can use confidently and safely.
• Serverless & Cloud Infrastructure: Use your AWS experience (Lambda, API Gateway, S3, EventBridge, SQS, CloudWatch) to build and run the event-driven services that sit behind the product. Care about observability, idempotency, and graceful failure in distributed, asynchronous systems. Working hand-in-hand with your product manager, you'll bring clarity to complex problems and help define sharply scoped, impactful deliverables. Your success won't be measured by output alone, but by the lasting impact you make on our customers and on the team around you.

Curious how we build the future of fleet insurance? Dive into our Product & Engineering Blog, packed with technical deep-dives, behind-the-scenes stories, and real insights from the team you'd be joining.