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 Senior 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.
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 platform
Building and owning core services across benefits, allowances, payments, and reporting
Developing scalable data models and ensure integrity across systems
Improving platform reliability, performance, security, and observability
Automating workflows and Go Rules to streamline complex operations
Collaborating closely with product and frontend teams to ship end-to-end features
Writing clean, well-tested, production-ready code
Using AI tools to accelerate development and iteration
Contribute 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
4+ years experience as a Backend or Software Engineer
Strong experience with modern backend languages and frameworks (e.g. Typescript, Golang)
Experience designing and consuming APIs (REST, event-driven systems)
Solid understanding of databases (SQL / PostgreSQL) and data modelling
Experience building and scaling production systems
Familiarity with cloud infrastructure and CI/CD workflows
Comfortable working with integrations and third-party services
Experience using AI tools (e.g. ChatGPT, Claude) as part of your workflow
Clear communicator who works well with both technical and non-technical stakeholders
Proactive, 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 benefits
Competitive base salary and commission
Meaningful equity in an early stage growing business
Flexible hybrid working from day one
Access to your own Happl benefits platform
Optional enrolment in Private Health Insurance
Optional enrolment in Dental insurance, including family cover
A flexible Wellbeing budget to spend on whatever wellbeing means to you
Learning & Development (L&D) allowance
Pension scheme from day one
Rapid career progression in a scaling commercial 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 Task
Call 3: 30-min deep dive with Ben T (CEO & Founder)
Additional Details
Location: London, Waterloo
Team: Engineering
Working arrangement: Hybrid (3+ Days in Office)
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