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.

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

3+ years experience as a Backend or Software Engineer

Strong 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 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 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 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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