Web: Full Stack Tech Lead

Posted 1 day 12 hours ago by Clarity

£50,000 - £80,000 Annual
Permanent
Full Time
Other
London, United Kingdom
Job Description

Full-Stack Web Developer - React, FastAPI, Elasticsearch (AWS/GCP)

About Clarity

Clarity is redefining customer experience with AI. Our mission is to empower businesses to deliver faster, smarter, and more human service interactions. By combining cutting edge AI with intuitive design, we enable customer service teams to operate more efficiently while providing customers with seamless, personalized experiences.

We are trusted by industry leaders like OpenAI, GrubHub, STC and Tabby who rely on us to deliver real impact. Our investors include Prosus Ventures, STV AI Fund (backed by Google) and angels from Open AI and Google. With a 25% month on month growth rate and over 300% net revenue retention, this is a unique opportunity to join a hyper growth AI company and redefine an industry.

As a Full Stack Web Developer at Clarity, you'll own end to end product surfaces-from sleek React UIs to FastAPI services and Elasticsearch search/ -shipping fast, safely, and beautifully. You're AI native (Cursor, v0, Claude Code in your muscle memory), comfortable in both AWS and GCP, and you treat infra & DevOps as part of building great product, not an afterthought. You'll collaborate directly with engineers, PMs, and the CTO to turn specs into production features used by brands like Grubhub, Booking, Dropbox & Uber.

What you'll do

50% Build - design & ship

  • Build responsive React (TypeScript) frontends (state mgmt, data viz, virtualized tables, forms, charts, file uploads, accessibility).

  • Implement FastAPI services (async I/O, Pydantic v2, background jobs, caching) with robust testing.

  • Design Elasticsearch models & queries

  • Integrate AI features (streaming responses, structured outputs, eval hooks) to accelerate prototyping and user value.

25% Scale & operate

  • Ship and run services on AWS and/or GCP (ECS/EKS/Lambda or Cloud Run/GKE), containerized with Docker.

  • Own CI/CD (GitHub Actions), IaC (Terraform), logging/metrics/tracing (OpenTelemetry, CloudWatch/Stackdriver, Grafana/Prometheus), and SLOs.

  • Optimize p95 latency, throughput, and cost; manage secrets, networking, VPCs, and build resilient retries/backoffs.

15% Collaborate

  • Work closely with design/PM on specs and UX polish; pair with back end/ML on data contracts and APIs.

  • Partner with the Insights team on taxonomy/schema changes and with Data/ML on search & analytics expectations.

10% Align & showcase

  • Write crisp docs, PRDs/tech notes, and demo your work to execs & customers.

  • Contribute to on call for your services and drive post mortems to closure.

What makes you a great fit

  • Owner's mindset: you take ideas from zero shipped observed iterated; you sweat details and outcomes.

  • AI native builder: Cursor, v0, Claude Code (and friends) are daily drivers for rapid prototyping and refactors.

  • React + TypeScript mastery: component design, hooks, performance, testing (Vitest/Jest, Playwright).

  • FastAPI expertise: async patterns, Pydantic schemas, pagination, auth (OAuth2/OIDC), rate limits, background jobs.

  • Elasticsearch fluency: mappings/analyzers (ngrams, synonyms), aggregations, filters, sorting, performance tuning.

  • Cloud & DevOps: solid experience on AWS and/or GCP, Docker, Terraform, GitHub Actions, monitoring/alerts.

  • Datastores: Postgres (SQL, migrations), Redis (caching/queues).

  • Quality & security: code reviews, type safety, lint/format, secrets mgmt, least privilege IAM, basic SOC2 hygiene.

  • Communicates clearly with product sense; ships value weekly.

Perks and bonuses

  • Remote first freedom & flexible hours

  • Regular off sites & monthly virtual game nights

  • Unlimited vacation (minimum 20 days encouraged) ️

  • Learning budget for conferences, courses & books

  • Startup equity in a rapidly growing market