Product Engineer

At Affinity Labs, we’re building a full-stack AI venture studio that partners with content creators to co-found authentic, scalable software businesses. By combining AI-native development with creator-led distribution, we are pioneering a new model of monetisation by rapidly building, launching, and scaling digital ventures alongside creators and their audiences.

You’ll lead end-to-end product engineering across our portfolio: scoping features, designing APIs and data models, building backend services, and shipping polished user-facing experiences across web and mobile. This is an early-stage, hands-on role with significant autonomy and responsibility. You will own full-stack product delivery, from infrastructure and AI integrations through to React / React Native interfaces, collaborating closely with founders, creators, product, and design to turn lean specs into scalable, user-loved software.

Responsibilities:

• Implement features end-to-end (mobile + web frontend → APIs → data models → integrations) while maintaining quality and velocity.
• Build React Native mobile apps and shared component systems across products.
• Design and ship scalable backend services (APIs, integrations, AI workflows).
• Run tight build → test → iterate → ship loops; provide realistic estimates and surface blockers early.
• Manage tech debt pragmatically.
• Participate in daily standups and weekly planning; contribute to technical strategy and execute from Linear tickets.
• Contribute meaningfully to product and architecture discussions; be heard in debate and align to unified decisions.
• Own operability: CI/CD, monitoring/alerting, performance optimisation, safe rollbacks.
• Build and integrate AI features (LLM/agent workflows, RAG/vector DB integration, eval hooks, cost/safety guardrails).
• Help evolve our reusable product templates and shared architecture across the portfolio.

Essential Requirements:

• 3-6+ years building production-grade full-stack applications, with clear ownership.
• Strong backend experience in Python (FastAPI preferred) and solid database skills (PostgreSQL/MongoDB).
• Proven experience building and shipping mobile apps with React Native.
• Strong React fundamentals (Next.js experience a plus).
• Solid API design and systems thinking.
• Familiarity with AWS serverless patterns and Docker; basic CI/CD concepts.
• Comfortable with Redis (caching/sessions) and queue/messaging patterns.
• Startup mindset: high ownership, comfort with ambiguity, bias toward shipping.
• Growth mindset not rigid about stack/tools.
• Clear communicator able to guide product decisions from engineering perspective.
• Evidence of shipping quickly in small teams (links to apps, repos, case studies, live products).

Desired:

• Node.js alongside Python for services or integrations.
• App Store / Google Play release experience.
• Experience with vector databases (e.g., Chroma) and embedding pipelines.
• LangChain or CrewAI for orchestration; MCP servers for integrations.
• Security hygiene (secrets, permissions, least-privilege) and practical data-privacy basics.
• Infrastructure: AWS (serverless functions), Docker (primarily for custom MCPs).

Why this role is a career launchpad:

• Own the code we need driven people who can help us achieve an ambitious roadmap.
• Grow like crazy. You’ll architect, build, and launch multiple products each year.
• The shipping reps you’ll get in 12 months here would take 3–4 years in a typical startup.
• There’s a lot of work, it’s high intensity, and the expectation is to ship extremely quickly.
• Learn from builders, not bosses. Work shoulder-to-shoulder with a team that has scaled VC-backed startups, closed multi-million-pound term sheets, and collaborated with 1,000+ creators across formats and categories.