Full Stack Engineer in London

Willis Re is building its global technology estate from the ground up, unencumbered by legacy and designed around data, analytics and modern cloud platforms. We are looking for a Full Stack Engineer to build the products that power our reinsurance broking, analytics and client-facing platforms. This is a hands-on engineering role for someone who enjoys working across the whole stack and is equally comfortable building conventional services and AI-enabled features. You will work alongside architects, product stakeholders and delivery partners to ship software that brokers and analysts use every day.

Key Responsibilities

• Build Across the Stack: Design, build and ship features end to end, from APIs and services through to responsive, accessible user interfaces.
• Cloud Native Delivery: Develop and run cloud-native applications on Microsoft Azure, using PaaS services, containers and infrastructure-as-code.
• Data-Driven Features: Consume data through APIs and services to surface it in usable, performant ways for brokers and analysts.
• AI-Enabled Development: Build AI-enabled product features using patterns such as retrieval-augmented generation, tool and API integration, evaluation and human-in-the-loop design.
• AI-Assisted Engineering: Use AI-assisted engineering tools such as Claude Code or Claude Cowork as part of your day-to-day workflow, and help the wider team adopt them well.
• Integration: Integrate with external market platforms, carrier and client systems, and vendor SaaS products using API-first and event-driven patterns.
• Quality & Security: Practise test-driven development and write secure, maintainable code, applying established security patterns including authentication and authorisation (Entra ID, OAuth 2.0), data protection and privacy from the start.
• Collaboration: Build to the agreed architectural standards and help shape them, contributing to design discussions, reviewing code from in-house and partner engineers, and mentoring others across a greenfield estate.

About You

You are a pragmatic, hands-on engineer who enjoys a fast-moving, greenfield environment and wants to work across both traditional and AI-native development. Ideally you will bring:

• Experience: Extensive experience of professional software engineering experience, with a track record of shipping and supporting production systems end to end. Experience in insurance, reinsurance or wider financial services is a plus, but not essential.
• Backend: Strong programming skills in C#/.NET or Python, with solid API design and strong SQL.
• Frontend: Practical experience building modern user interfaces with React or Angular and TypeScript.
• Cloud & DevOps: Hands-on experience with Azure, CI/CD tooling such as Azure DevOps or GitHub Actions, and infrastructure-as-code (Terraform).
• Standards & Security: Experience building to architectural standards and applying common patterns such as microservices, event-driven and API-led design, together with a strong grounding in security patterns (OAuth 2.0, OIDC, Entra ID, RBAC) and secure coding practices.
• Data: Comfortable working with relational databases and data-heavy application features, with strong SQL and an eye for query performance.
• AI Development: Experience building with LLMs and AI-enabled solutions, or a clear appetite to learn. Familiarity with agentic patterns, prompt design and evaluation is a significant advantage.
• Engineering Craft: Fluency in test-driven development and automated testing, an eye for maintainable design, and good judgement about when to keep things simple.
• Communication: Ability to work closely with product stakeholders and delivery partners, and to explain technical trade-offs clearly.

About Willis Re

We combine specialist broking with analytics, modeling and research to help insurers optimize risk transfer, strengthen balance sheets and achieve sustainable growth. Our approach is relationship-driven, transparent and outcome-focused. At the heart of Willis Re is a focus on delivering the most cutting-edge analytical solutions to enable more informed, better decision-making for risk selection, portfolio optimization, and capital management. The launch of Willis Re brings a strategic advantage of being unhindered by legacy, an ability to leverage data, statistical models and advanced technologies with the best knowledge and expertise to deliver more efficient and effective reinsurance outcomes. This places Willis Re in a unique position to build a truly analytically driven business, focused on creating solutions for the reinsurance industry that are future-led and forward-thinking. Willis Re will also leverage recognized technical expertise from WTW’s Insurance Consulting & Technology business including their advanced modeling and analytical capabilities. Alongside this will be WTW’s Research Network, an award-winning business supporting and influencing science to improve the understanding and quantification of risk. Willis Re is committed to embracing a diverse, inclusive, and flexible work environment. We provide equal opportunity to all qualified individuals regardless of race, colour, religion, age, gender, gender expression, national origin, veteran status, disability, orientation, or any other legally protected categories.