Senior Software Engineer (Next.js, Go)

Frontend Software Engineer (Next.js, Go) with QA ownership — Artsem.ai

About Artsem.ai Artsem is an AI shopping assistant and marketplace for fashion. We are hiring a frontend engineer who also owns quality on the web. You will build the Next.js pages that shoppers, merchants and our own team use, and you will be the person who knows whether a release is safe to ship. Shoppers search and chat in natural language (or by photo) across a catalogue of thousands of independent stores, on the web at artsem.ai and on iOS. Merchants onboard their store, list products, sell through Artsem checkout and get paid out.

The whole platform is in production and run by a small team.

What you will work onYou will work across three Next.js apps and read and change the Go services behind them:

• Shopper web (artsem.ai). Search and chat, product and store pages, saved items and shareable collections, virtual try-on. Next.js on Cloudflare Workers, talking to a streaming chat over WebSockets.
• Seller platform (sell.artsem.ai). Store onboarding, multi-store accounts on one login, a product catalogue, orders, shipment tracking and Stripe Connect payouts.
• Admin app. Internal tools for merchant review, platform analytics, and search quality, which is scored on evaluation sets.
• Quality on the web. Today the frontends have unit and component tests (Jest, Vitest, Testing Library) but no browser end-to-end suite, and one of the apps doesn’t run tests in CI at all. You will build the E2E suite for the critical paths and wire it into CI:
  • search and chat;
  • sign-in;
  • checkout;
  • seller onboarding.
• Releases. Regression checks before a release, test plans for new features, checks on production behind test-user flags, and turning Sentry errors and PostHog sessions into reproducible bugs.
• Go, on the backend side. Our services are in Go. You will read the handlers your pages call, write API and integration tests, and fix small backend bugs yourself instead of filing them and waiting.

Typical work: take a feature from the API contract, build the screen in Next.js, cover it with unit and E2E tests, check it on production behind a test-user flag, then sign off the rollout. When a bug comes in, find out whether it lives in the page or the service, and fix it or hand it over with exact reproduction steps.

Our stack: Next.js (App Router), React, TypeScript, Cloudflare Workers / OpenNext, Jest, Vitest, Testing Library, Go, Azure Container Apps, Azure AI Search, Cosmos DB, Azure SQL, WebSockets, Firebase Auth, Stripe Connect, PostHog, Sentry, GitHub Actions.

What we expect

• 3+ years of frontend engineering with strong React, Next.js (App Router) and TypeScript:
  • server and client components;
  • data fetching;
  • routing and forms;
  • responsive layouts. You run the production build before calling a change done.
• Hands-on test automation: you have built an end-to-end suite (Playwright or Cypress) that a team relied on and kept it stable, not flaky. You know what belongs in a unit test, a component test and an E2E test.
• You think like QA: you write test plans and find edge cases (auth, empty states, slow networks, mobile browsers), and your bug reports can be reproduced on the first try.
• Working knowledge of Go: you can read a handler, follow a request through a service, write a table-driven test and make a small fix. No production Go experience required, but you are willing to grow into it.
• You understand HTTP and WebSocket APIs from the client side: auth (JWT), error handling, retries, reconnects, and API versioning.
• You can debug production from Sentry, logs and analytics data without guessing.
• Working English for reading and reviewing tickets, pull requests and specs, and for writing test plans and async updates.

Nice to have

• Production Go, even if it was a small service.
• Testing apps with streaming or real-time UI (chat, WebSockets).
• Cloudflare Workers / OpenNext, edge rendering, Core Web Vitals.
• Testing payment flows (Stripe test mode, webhooks).
• Accessibility testing, visual regression, cross-browser and mobile web testing.
• Evaluating quality of AI or search features with evaluation sets, not by eye.
• E-commerce or fashion catalogue data.
• Using AI coding agents (Claude Code, Cursor) daily. Our repos carry agent docs and skills, and we expect you to work with them.

How we work

• Small team, short path from idea to production. You talk directly to the people building the iOS apps and running the business.
• Every repo has its own tests, deploy scripts and docs. Production changes go through pull requests and CI.
• Decisions are made on data: eval sets for search quality, analytics for user behaviour, Sentry for errors.
• No legacy rewrite waiting for you. The code is modern Next.js and Go, but you will find gaps in test coverage worth closing, and you are trusted to close them.

What we offer

• Compensation: $1,500 per month
• Full-time position
• Working hours: 9−5

To applySend your CV or LinkedIn profile and a few lines about a test suite you built: what it covered, how you kept it stable, and a bug it caught before release.