Senior Backend Engineer - Java/Kotlin

Backend Engineer – Java / Kotlin / Spring Boot London – Hybrid (1 day per week) Up to £100,000 + Share Options Unfortunately, sponsorship cannot be provided I'm working with a growing technology startup looking to hire a Backend Engineer to join its engineering team in London. They're looking for someone who is genuinely strong technically – not just someone who has worked with the right technologies. You'll be joining a small, high-performing team where you'll have significant ownership over backend systems, contribute to architectural decisions and help shape how the platform develops as the business scales. What they're looking for The core requirements are: Strong, recent commercial Java experienceStrong, recent commercial Kotlin experienceStrong commercial Spring Boot experienceIdeally 2+ years within a technology startup or scale-upExperience working in smaller engineering teams where you've had genuine ownershipStrong understanding of backend architecture, APIs, databases and distributed systemsAbility to discuss technical decisions, architecture and trade-offs in depthComfortable taking a problem from initial requirements through design, development, testing and production What will make you stand out We're particularly interested in engineers who can demonstrate examples of: Designing backend services or systems from scratchMaking and defending architectural decisionsSolving scalability, reliability or performance problemsWorking with microservices and event-driven architecturesTaking ownership of business-critical product featuresWorking directly with product teams, founders or senior stakeholdersSeeing a startup product evolve and scale over several years The opportunity You'll join a product-focused technology business where engineering has a significant influence over the direction of the product. This isn't a role where you'll simply be handed tickets to complete. You'll be expected to understand the problem, contribute to the solution and be able to explain why you've chosen a particular technical approach. The company is open to strong mid-level or senior engineers, with a salary of up to £100,000 plus share options. The role requires 1 day per week in London. Please note: the company cannot provide visa sponsorship, so applicants must already have the unrestricted right to work in the UK. If you're currently building backend systems with Java, Kotlin and Spring Boot, have meaningful startup/scale-up experience, and enjoy getting into the technical detail of what you're building, I'd be keen to speak with you.