Web: Full Stack Tech Lead

Clarity

Greater London

Remote

GBP 50,000 - 80,000

Full time

14 days+

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Benefits offered by this job

Remote-first freedom

Regular off-sites

Unlimited vacation

Learning budget

Startup equity

Job summary

A leading AI company in the UK is seeking a Full-Stack Web Developer to design and ship React UIs and FastAPI services. The ideal candidate will work with cutting-edge technologies and contribute to projects that transform customer service interactions. This position offers a remote-first culture and benefits such as unlimited vacation and startup equity.

Qualifications

Proven experience with React and TypeScript.
Strong background in FastAPI and Elasticsearch.
Experience with AWS and GCP for deploying applications.

Responsibilities

Build responsive React frontends and implement FastAPI services.
Ship and run services on AWS or GCP, managing CI/CD.
Collaborate with design/PM on specifications and UX.

Skills

React

TypeScript

FastAPI

Elasticsearch

AWS

GCP

Docker

Terraform

Postgres

Redis

Tools

GitHub Actions

OpenTelemetry

Grafana

Prometheus

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.