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- Tasks: Build and scale backend systems for a global AI-first benefits platform.
- Company: Join Happl, a top UK startup backed by leading investors like YCombinator.
- Benefits: Competitive salary, equity, flexible working, and wellbeing budget.
- Other info: Rapid career progression in a dynamic, supportive engineering team.
- Why this job: Shape the future of employee benefits while making a real impact.
- Qualifications: 3+ years in backend engineering with strong API and database skills.
The predicted salary is between 36000 - 60000 £ per year.
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.
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
- 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 ensuring 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
- Contributing 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 (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 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)
Backend Engineer employer: Happl
Contact Detail:
Happl Recruiting Team
StudySmarter Expert Advice 🤫
We think this is how you could land Backend Engineer
✨Tip Number 1
Network like a pro! Reach out to folks in your industry on LinkedIn or at meetups. We all know that sometimes it’s not just what you know, but who you know that can help you land that Backend Engineer role.
✨Tip Number 2
Show off your skills! Create a portfolio showcasing your projects, especially those involving backend systems and AI tools. This gives us a chance to see your work in action and how you tackle real-world problems.
✨Tip Number 3
Prepare for the interview! Research Happl and understand our mission. Think about how your experience aligns with building scalable backend services. We want to see your passion for creating impactful solutions!
✨Tip Number 4
Apply through our website! It’s the best way to ensure your application gets seen by the right people. Plus, we love seeing candidates who take the initiative to connect directly with us.
We think you need these skills to ace Backend Engineer
Some tips for your application 🫡
Tailor Your CV: Make sure your CV is tailored to the Backend Engineer role at Happl. Highlight your experience with backend languages, API design, and any relevant projects that showcase your skills in building scalable systems.
Craft a Compelling Cover Letter: Your cover letter is your chance to shine! Use it to explain why you’re excited about the role and how your background aligns with Happl’s mission. Don’t forget to mention your experience with AI tools and cloud infrastructure!
Showcase Your Projects: If you’ve worked on any interesting projects, especially those involving backend architecture or AI, make sure to include them in your application. We love seeing real-world examples of your work and how you tackle challenges.
Apply Through Our Website: We encourage you to apply through our website for the best chance of getting noticed. It helps us keep track of applications and ensures you’re considered for the role as quickly as possible!
How to prepare for a job interview at Happl
✨Know Your Tech Stack
Make sure you’re well-versed in the modern backend languages and frameworks mentioned in the job description, like Typescript and Golang. Brush up on your API design skills and be ready to discuss how you've built and scaled production systems in the past.
✨Showcase Your Problem-Solving Skills
Prepare to discuss specific challenges you've faced in previous roles and how you tackled them. Highlight your experience with databases and data modelling, as well as any instances where you improved platform reliability or performance.
✨Communicate Clearly
Since you'll be working closely with both technical and non-technical teams, practice explaining complex concepts in simple terms. This will demonstrate your ability to collaborate effectively across different departments.
✨Embrace AI Tools
Familiarise yourself with AI tools like ChatGPT and Claude, as they are part of the workflow at Happl. Be prepared to discuss how you've used these tools to enhance your development process and improve efficiency.