Senior Staff Full Stack Engineer

Build the Future of Wellbeing

Do Your Lifes Best Work

If modern wellbeing were redesigned from scratch it wouldnt live in a GPs office or a cluttered supplement aisle. It would be digital-first beautifully curated and powered by data that actually helps you feel your best.

Thats what were building at Healf. An ecommerce platform at the intersection of personalised health and curated wellbeing. We connect customers with the worlds most effective products across EAT MOVE MIND and SLEEP and were just getting started.

We combine culture-shaping storytelling cutting-edge health tech (like our new blood testing platform Healf Zone) and a best-in-class product experience to help people build rituals that work.

Backed by investors behind Soho House Alo Yoga Cult Beauty and Innocent were scaling fast and redefining how the world shops and lives well.

About Us

At Healf were not just a company were a movement. Founded by two brothers whose own wellbeing journeys inspired our mission to empower others Healf is built on grit determination and a shared understanding of the power of wellbeing.

Our culture is grounded in The Healf Standardfive principles that define how we work and win:

We Work Harder Than Anyone Else: Building something that improves lives takes long hours grit and sacrifice but we thrive on it. We all feel energised by what were building.

Never Settle: We challenge the status quo and push ourselves to be better every day. We never settle for mediocrity or the idea that something cant be done.

Obsession Over Talent: Talent alone isnt enoughrelentless curiosity and a drive to grow set us apart.

The Healf Lifestyle: We live what we preachour personal commitment to wellbeing fuels our professional productivity.

Stronger Together: Everyone owns their lane but we run as a unit.

With Healf Zone on the horizon were entering the next phase of our journey: closing the loop on health with personalised preventative care that unlocks longevity and optimised wellbeing. This is your chance to help build something thats not only extraordinary but a first of its kind.

The Role

Were scaling rapidly across Web/Frontend and Backend/AI. To keep pace we need a hands-on technical leader who can balance deep execution with architectural foresight. Youll bridge strategy and implementation: co-creating architecture and engineering standards with the Head of Engineering while directly leading teams to build systems that scale sustainablywithout bottlenecks.

Location: Remote Open to candidates based anywhere in the UK/EU Time Zones.

Key Responsibilities

Own architecture & systems design. Define high-impact decisions across frontend and backend (service boundaries data flows ADRs UI composition BFF patterns). Evolve our API and event-driven designs for scale and reliability.

Lead execution endtoend. Drive projects from discovery design implementation production. Align scope with Product & Design surface trade-offs early and keep teams unblocked.

Build excellent services. Ship robust Python/FastAPI microservices and TypeScript/React (ideally ) frontends. Use (Express/Fastify/NestJS) for BFFs/edge services where it fits. Back with PostgreSQL/Redis/Elasticsearch (or OpenSearch) for performance resilience and cost efficiency.

Asynchronous comms at scale. Design and implement async workflows (Kafka/SNS/SQS/EventBridge) sagas/outbox idempotency retries and backpressure; champion distributed tracing and welldefined contracts.

Infrastructure as code. Stand up and evolve AWS with Pulumi/Terraform (VPC ECS/EKS or Lambda API Gateway/ALB CloudFront) manage secrets and networking and automate CI/CD (GitHub Actions/ArgoCD). Use CDNs/edge where appropriate (e.g. CloudFront/Cloudflare/Vercel).

Observability & Reliability. Establish SLIs/SLOs. Integrate logs/metrics/traces (OpenTelemetry Prometheus/Grafana/Datadog/Sentry). Add frontend observability (RUM error tracking Core Web Vitals) and drive actionable alerts and incident reviews.

Security & Governance. Apply AWS Well-Architected least-privilege IAM secret management SDLC controls and OWASP-aware web security (CSP CSRF SSRF mitigations). Partner on data/privacy (e.g. GDPR).

Mentor & Uplift. Lead through design walkthroughs pairing and code reviews across frontend and backend. Help engineers level up and take on bigger problems.

Greenfield & Modernisation. Lay foundations for new domains (mobile backend new verticals) while improving existing systems (performance reliability cost). Guide migrations (e.g. to RSC/ App Router typed APIs)

Team Leadership. Set engineering standards facilitate technical planning coordinate across squads and influence hiring/interviews. Provide calm decisive technical leadership.

Crossfunctionally. Turn business goals into pragmatic technical plans; communicate trade-offs clearly to non-engineers.

Qualifications

Deep Backend Mastery: Python 3.x FastAPI/Flask; SQL schema design & query performance; caching strategies; robust testing (pytest property-based integration).

Frontend Capability: Strong TypeScript/React ( preferred) component architecture state/data fetching (TanStack Query) forms accessibility (WCAG 2.1) performance (Lighthouse Web Vitals) and SSR/SSG/ISR.

experience: Building BFFs/edge APIs with Express/Fastify/NestJS; API design (REST/JSON; bonus for GraphQL/gRPC); familiarity with tRPC a plus.

Modern Microservices: Event-driven patterns resilience (circuit breakers bulkheads timeouts) contract testing and API versioning.

Cloud & IaC: Strong AWS (networking compute storage security). Production Pulumi and/or Terraform. Containers (Docker) and orchestration (ECS/EKS) or serverless where it fits.

Data & Search: PostgreSQL at scale; working knowledge of Elasticsearch/OpenSearch (indexing relevance aggregations).

Observability Culture: Youve stood up tracing/metrics/logging from scratch and used them to drive reliabilityboth backend and frontend.

Leadership through Craft: Excellent taste in code clear docs/ADRs and steady decision-making. Proven mentorship and leading multi-team initiatives.

Bias for Delivery: You break down complexity make smart tradeoffs and ship.

Nice to Have (Not Required):

Design systems (Storybook) Tailwind/Chakra advanced forms (React Hook Form/Zod).

GraphQL (schema design federation) tRPC Prisma/SQLAlchemy.

Vector search/retrieval ML-adjacent pipelines feature flags/experimentation.

WebSockets/WebRTC background jobs/cron orchestration.

Performance profiling (backend & frontend) cost-aware architecture.

Experience with LangChain/agentsuseful but optional.

Why Join Healf

Do your lifes best work: Build something that matters with a team that moves fast and aims high

Surround yourself with A talent: Youll work with high-performers who care deeply and raise the standard every day

Be a builder: This isnt a cog-in-the-machine role. Youll help shape our voice culture and growth

Wellbeing is the lifestyle: From office yoga to Healf Zone insights everything we do is rooted in our pillars: EAT MOVE MIND SLEEP

Premium Wellhub Membership: Unlimited entry to 1000s of gym yoga & fitness studios (UK Only)

Exclusive Healf Perks: 50% off all Healf products plus discounted Healf Zone blood testing.

Nest Pension: Secure your future with our pension contributions. (UK Only)

Wellbeing-Focused Workspace: Incredible Hammersmith office with great natural lighting (Optional Workspace if UK-Based)

Team Connection: Annual company-wide retreat to recharge and bond.