Job Specifications
Senior Full-Stack Engineer (TS/React/Next.js + Python)
Location: London (hybrid/remote flexibility)
Type: Full-time
Team: Engineering
Stack: Next.js · React · TypeScript · tRPC · Rust · C++ · Tailwind CSS · Python · FastAPI · Datafusion · MongoDB · RabbitMQ · Redis · Temporal.io · Kubernetes · GitLab
Why RootCause.ai
RootCause.ai is a fast-moving startup building data-driven products that help teams understand what happened and why. We ship quickly, learn constantly, and keep process light. You will work with founders daily, own meaningful product areas end to end, and see your work in production within days, not quarters, with AI-assisted workflows across the stack.
The role
This is a full-stack role for product development. You’ll build polished, data-heavy product experiences and the typed APIs behind them. You’ll care about UX, performance, correctness, and reliability—and you’ll enjoy turning ambiguous problems into shipped software.
What you’ll do
Ship user-facing product features in Next.js/React/TypeScript: reusable Tailwind components, complex states, and data-heavy views
Design clean, typed contracts between UI and backend using tRPC and FastAPI
Build product workflows end-to-end: from UX to API to persistence (MongoDB) to async processing (Temporal/RabbitMQ) where needed
Own quality pragmatically: performance profiling, testing where it matters, and observability/diagnostics to keep production healthy
Collaborate closely with founders and users: scope, prototype, iterate, and ship improvements based on real feedback
Contribute to deployment/ops on Kubernetes and GitLab CI/CD (you don’t need to be a platform engineer, but you won’t fear production)
What success looks like (first ~90 days)
You’ve shipped multiple meaningful product improvements with clean UX and stable APIs
You’ve taken ownership of at least one product area (features + metrics + reliability)
You’ve improved one “pain point” (latency, workflow reliability, DX, or UI performance) and made it measurable
Must-have
Strong TypeScript + React + Next.js experience shipping real products
Strong Python experience (FastAPI or similar), comfortable building/maintaining APIs
Product mindset: you clarify goals, reduce scope intelligently, and ship value quickly
Comfort working end-to-end: UI state, data modeling, API design, basic infra/ops concepts
Solid fundamentals: debugging, performance reasoning, and clear async communication
Strongly Preferred
Temporal and/or event-driven systems (queues, retries, idempotency, background jobs)
Kubernetes and cloud experience (AWS/GCP/Azure)
Data/analytics experience: DuckDB, Parquet/Arrow, large datasets, query performance
Observability (OpenTelemetry or similar): traces/metrics/logs; production debugging chops
Rust and/or C++ experience
Good to Have
Public code, technical posts, or talks
Personal projects
Examples where you reduced scope to ship faster without hurting quality
Stories of debugging tough production issues and how you prevented repeats