Lead Software Engineer

Who you are

• 8+ years building backend systems in production, with real depth in Kotlin and/or Java (17+) and the Spring ecosystem (Boot, Web, Security, Data)
• A track record of architecting systems, not just services: you've owned significant design decisions in a distributed or microservices platform and lived with the consequences
• Strong data modelling and SQL skills, plus experience designing data ingestion, transformation or ETL pipelines. You've dealt with data you couldn't trust
• Enough Python to design and review it. Our metrics, analytics and AI services are written in it, so you need to be able to reason about them, not to be a Python specialist
• Fluency across the boundary: you can read and reason about a React/TypeScript frontend and hold a serious conversation about Kubernetes, cloud networking and cost
• You work well with Product. You've partnered closely with a PM, dug into complex business requirements, challenged them, and turned them into plans a team could execute
• You write. Technical specs, design docs, ADRs. Clear enough that another architect can challenge them and an engineer can build from them
• Comfortable with AI-assisted development. You use coding agents day to day and have a view on where they help and where they quietly cause damage. Experience writing skills, MCP integrations or agent conventions for a team is a strong plus
• Security is instinctive for you. Secure-by-design services, authentication and authorisation done properly, tenant and data isolation, secrets and key management, dependency and supply-chain hygiene. You've worked somewhere the data mattered
• You've built for scale and kept it up. Designing for growth in users, data volume and history; understanding availability, failure modes, graceful degradation and recovery; and being the person who owns the incident rather than watching it
• Performance is something you measure. Profiling and load testing before optimising, query and caching strategy, sensible use of async and batch, and knowing which numbers actually matter to a client waiting on a report
• A real testing habit, and a view on what belongs where: unit, component, integration, contract, end-to-end, and performance and scalability testing. You know which of these earns its keep on a given change, and which ones teams quietly skip until it hurts
• Comfortable with Docker, Git, trunk-based or short-lived branching, and CI/CD as code
• Experience leading engineers. You've line-managed or formally led a team, and you can point to people who got significantly better while working for you
• You lead through influence and clarity. You explain a design to a junior engineer and a product director in the same afternoon, in the right words for each
• Fluent English. Degree in Computer Science, Mathematics or another STEM subject, or equivalent experience
• You don't need to come from finance. You do need to be curious about it, because the domain is half the job

What the job involves

• As technical lead of an R&D team, you'll work closely with a Product Manager on initiatives, improvements and bugs: shaping the work, breaking it down, handing it out across the team, and owning what ships
• You go deep enough into the requirement to push back on it, ask the questions that need asking, and tell apart what the client needs from what the requirement says
• Then you work out how it fits
• Usually the right answer is the simple one built on architecture we already have, and defending that is part of the job
• Sometimes it isn't, and you're the one who flags that this is a truly new capability, writes the spec and plan, and takes it to our other architects to poke holes in before we commit
• You'll do all this in a team that uses coding agents every day, and you'll help shape how we do that well
• You own the partnership with Product: one PM, one lead engineer, one roadmap
• You sit with product and domain experts before the ticket exists, understand the business problem, push back on the requirement where it needs it, and come back with honest trade-offs on cost, risk and time
• You plan, size and hand out the work, and keep the team unblocked while it ships
• Security, scalability, availability and performance are design inputs on every initiative, not a hardening phase at the end
• You cover tenant isolation, auth, data protection and auditability, because our clients' data is about as sensitive as it gets
• You know how the system behaves under load and at month-end when everyone runs reports at once, you set the SLOs, and you make sure we can see whether we're meeting them
• You are the escalation point when the team hits something genuinely hard, and you go in and solve it with them
• For every significant initiative you produce the design: what changes, in which services, what the contracts and data flows look like, what we reuse and what we leave alone
• You write it down, take the challenge from our other architects, and improve it
• When a requirement exposes a gap in the platform, you name it and propose what should exist
• You own feature architecture end to end, from the React frontend through our Kotlin and Spring services, across data stores and events, down to Azure
• You decide what goes where, and push hard for the simplest solution the existing architecture can carry
• You set the coding standards, API design, testing, quality gates, and security and dependency hygiene
• That now covers how we work with coding agents: the rules they follow, the skills and MCP integrations we build over our own systems, and the review process that holds quality as more code gets generated
• You're the one who challenges what an agent proposed, because plausible code that passes its tests can still be wrong about concurrency, a data model or a failure mode
• You model the financial domain: positions, transactions, instruments, valuations, entities and hierarchies, so it holds up as new asset classes, custodians and jurisdictions arrive
• You build pipelines that stay correct when the source data is messy, late or wrong, and fast enough to run over long histories on demand
• You line-manage a squad: objectives, one-to-ones, feedback that moves careers, hiring, onboarding and code reviews people learn from
• You bring back what's new and make sure it lands with the team rather than staying in your head
• You stay hands-on throughout — this is not a role where you stop writing code
• ---Our stack---
• Core backend: Kotlin, Java 17+, Spring Boot & Co, JPA/Hibernate, SQL and NoSQL, Elasticsearch, Gradle, JUnit/AssertJ/MockK
• Metrics, analytics and AI: Python, FastAPI, Polars, LangChain
• Frontend: React (TanStack Query/React Router/react-hook-form + Zod), TypeScript, nx.dev, Tailwind CSS/shadcn/ui, Vitest/Playwright/MSW, Vite, Recharts
• Platform: Azure, Azure DevOps (CI/CD), Kubernetes, Docker, cloud storage, messaging and events, Git, SonarQube
• AI in our workflow: Claude Code and Codex day to day, custom skills, MCP servers over our own platform, LLM-powered document and data ingestion
• ---What the first year looks like---
• Month 1: you know the platform, the domain and the team, and you've shipped something real
• Month 3: you and your PM are running your initiatives together, and you've written the spec for a significant cross-service feature
• Month 6: your fingerprints are on our engineering conventions and on how the team plans, designs and reviews work
• Month 12: your team is noticeably stronger than the day you arrived, and the decisions you made are holding up under load

Benefits

• Stock options, with extra incentives for high performers for London and Paris-based employees
• Work between home and our offices with our hybrid working model
• Private health care coverage provided by BUPA
• Access to company Uber and Uber Eats account when working outside of normal office hours