Backend Engineer

We’re building the next generation of employee benefits infrastructure. At Happl, we help global teams design, manage, and scale benefits that actually work for their people by using AI, across flex allowances, benefits, insurance, recognition, and wellbeing, all in one intelligent platform. Happl is backed by leading investors such as YCombinator, 6Degrees Capital, and more, known for backing leading companies such as Deel, Rippling, Airbnb, Coinbase, Dropbox, and most recently was awarded a place in the UK’s top 100 startups for 2026. About The Role As a Backend Engineer at Happl, your mission is to build the systems that power a global, AI-first benefits platform. You’ll design, build, and scale backend services that are reliable, secure, and performant, enabling our product teams to move fast while supporting complex real-world use cases across payroll, finance, and employee benefits. This role is for someone who enjoys ownership, thrives in fast-moving environments, and wants to build foundational systems that directly impact how companies support their people. This is a hybrid role based in London, with an expectation of working from the office at least 2–3 days per week. What You’ll Be Doing This role sits within our Engineering team and works closely with Product, Frontend, Data, and Customer teams across the full development lifecycle. You’ll help shape how we build and scale our backend by focusing on: Designing and scaling the backend architecture powering a global, AI-first platformBuilding and owning core services across benefits, allowances, payments, and reportingDeveloping scalable data models and ensure integrity across systemsImproving platform reliability, performance, security, and observabilityAutomating workflows and Go Rules to streamline complex operationsCollaborating closely with product and frontend teams to ship end-to-end featuresWriting clean, well-tested, production-ready codeUsing AI tools to accelerate development and iterationContribute to architecture, technical decisions, and engineering standards You’ll play a key role in ensuring Happl’s backend scales as our customer base, features, and global footprint grow. What We’re Looking For 3+ years experience as a Backend or Software EngineerStrong experience with modern backend languages and frameworks (must have a working ability in Golang and Typescript)Experience designing and consuming APIs (REST, event-driven systems)Solid understanding of databases (SQL / PostgreSQL) and data modellingExperience building and scaling production systemsFamiliarity with cloud infrastructure and CI/CD workflowsComfortable working with integrations and third-party servicesExperience using AI tools (e.g. ChatGPT, Claude) as part of your workflowClear communicator who works well with both technical and non-technical stakeholdersProactive, detail-oriented, and comfortable taking ownership If you don’t meet every requirement but feel this role fits your trajectory, we’d still love to hear from you. Why join Happl Help shape the future of employee benefitsCompetitive base salary and commissionMeaningful equity in an early stage growing businessFlexible hybrid working from day oneAccess to your own Happl benefits platformOptional enrolment in Private Health InsuranceOptional enrolment in Dental insurance, including family coverA flexible Wellbeing budget to spend on whatever wellbeing means to youLearning & Development (L&D) allowancePension scheme from day oneRapid career progression in a scaling engineering team About The Interview Call 1: 20-min Intro call with Ben (COO & CoS)Call 2: 30-min deep dive with Lee (Head of Engineering)Short TaskCall 3: 30-min deep dive with Ben T (CEO & Founder) Additional Details Location: London, Holborn Team: Engineering Working arrangement: Hybrid (3+ Days in Office) #BS-L1