Senior Software Engineer

The Role

You’ll own application delivery across our clinic, patient and internal facing web applications, CLI tools and the APIs and data behind them. Working directly with the CTO as one of our first engineering hires, based in the UK, you’ll turn agreed user needs into clear specifications, working features and reliable software in production.

You’ll own application behaviour, feature quality, and diagnosis and fixes for the features you ship. You’ll also lead the technical design of our applications and set the engineering standards the team works to. The CTO provides technical direction and helps resolve decisions spanning the application and platform.

You’ll work with PureScript in the browser, Erlang (PureScript)/OTP backend services, PostgreSQL, event-sourced systems, AWS, Nix/NixOS and Terraform/OpenTofu. Prior PureScript experience is not required, but strong functional programming foundations and willingness to learn our stack matter.

What You’ll Do

• Build features from accessible, responsive interfaces through APIs to the database.
• Develop backend services and third-party integrations, including PostgreSQL models, queries and safe schema migrations.
• Develop event schemas, projections, idempotent processing and replay.
• Use behaviour-driven development (BDD): define acceptance scenarios and write failing tests before implementation to guide and independently verify agent-assisted changes. Use Playwright for user-facing acceptance and regression tests.
• Specify and coordinate substantial work with coding agents; review, debug and integrate their output yourself.
• Lead design and code review across our applications, and mentor other engineers in our stack and ways of working.
• Maintain representative, appropriately protected LLM and agent evaluation datasets, clear success criteria and reproducible benchmarks comparing task success.
• Release, observe and support your features on shared AWS infrastructure and reproducible Nix-based environments, partnering with our production engineer.

What We’re Looking For

• 7+ years of professional experience taking web application features from user need to production, including leading the design of production systems end to end.
• Strong SPA skills: HTML, CSS, responsive layouts, accessibility, WebSockets, client storage and browser debugging.
• Practical functional programming experience, ideally in a typed language, and an understanding of static typing and controlled side effects.
• Backend and API development experience, including SQL and relational data modelling.
• Experience building and maintaining reliable Playwright end-to-end tests and using test-first development to turn acceptance criteria into executable tests; no particular BDD framework is required.
• Experience directing coding agents through substantial implementation work, from specifications and acceptance criteria to task coordination, independent testing, review and integration.
• Practical LLM or agent evaluation experience: representative datasets, useful metrics, model/prompt comparisons, failure analysis and quality/cost/latency trade-offs.
• Ownership of outcomes and disciplined engineering: automated testing, code review, source control and CI/CD; improving team practices and shipping quickly while maintaining quality, security and compliance. Mentoring other engineers and growing Aykua’s engineering culture will be a core part of this role.

Nice to Have

• PureScript/Haskell/Gleam/Erlang/OTP or other functional language.
• CI/CD with GitHub Actions.
• Event sourcing (projections, idempotency and replay) and the actor model.
• Relational database schema design.
• Nix/NixOS.
• AWS and Terraform/OpenTofu.
• Security engineering, such as end-to-end encryption, WebCrypto or WebAuthn/passkeys.
• Healthcare integrations and compliance (HIPAA, FHIR, HL7 and related standards).
• Managing vendors and third-party suppliers.

Please note: We review applications on a rolling basis and aim to respond within one week. You must have the right to work in the UK.

Pay: £72,000.00-£95,000.00 per year

Benefits:

• Employee stock ownership plan

Education:

• Bachelor's (required)

Work authorisation:

• United Kingdom (required)

Work Location: Hybrid remote in Cambridge CB4