Senior Full-Stack Engineer (TS/React/Node) - Subscriptions

WhyHireWrong?; Łódź; On-site; PLN 180,000 - 280,000; Full time

Job summary

WhyHireWrong? is seeking a seasoned full-stack engineer to own features from idea to release in a seed-stage B2B SaaS environment.

You’ll work across frontend and backend with TypeScript, React on the frontend and Node.js on the backend, talking directly to designers and the founders. Turn Figma designs into accessible UI, shape simple, observable architecture, review code, write tests and maintain documentation.

Qualifications

• 5+ years of professional software engineering experience in product or SaaS environments.
• Strong TypeScript and Node.js in production with real customer features.
• Production experience with React.
• Experience shipping at least one customer-facing feature end-to-end.
• Ability to work from Figma designs.
• Independent contributor in an early-stage team without detailed specs.

Responsibilities

• Build and ship full-stack features in TypeScript with React frontend and Node.js backend.
• Own features end to end: requirements, approach, build, test, release, impact.
• Build merchant-facing subscription, billing and checkout flows.
• Improve developer-facing APIs, docs, integrations, onboarding and error messages.
• Turn Figma designs into accessible UI and suggest UX improvements.
• Keep architecture simple, observable and maintainable.
• Do code reviews, write automated tests and maintain useful documentation.
• Use AI coding tools where they save time or improve quality.

Skills

TypeScript

Node.js

React

Figma

Polish language

Independent work

Tools

Next.js

Vue

Nuxt.js

Fastify

Express

NestJS

Job description

WhyHireWrong? is seeking a seasoned full-stack engineer to own features from idea to release in a seed-stage B2B SaaS environment.

You’ll work across frontend and backend with TypeScript, React on the frontend and Node.js on the backend, talking directly to designers and the founders. Turn Figma designs into accessible UI, shape simple, observable architecture, review code, write tests and maintain documentation.