We're looking for a Mid/Senior Full Stack Engineer who builds end-to-end features on a sports-training platform — and uses AI tools daily to ship faster. Coaches plan and assign training programs in a web console; athletes train from a mobile app. You'll work in a modern TypeScript codebase built on Next.js, Postgres in Supabase and Clerk, owning everything from the database schema and security policies to a polished UI. This is a hands-on product engineering role where AI is part of the daily workflow.
Key Responsibilities
Build and ship full-stack features end-to-end with TypeScript, Next.js 16 (App Router, Server Components, Server Actions) and React 19
Design Postgres schemas in Supabase and secure them with Row-Level Security policies, migrations and generated types
Implement auth and role-based access with Clerk (organizations, roles, permissions) integrated with Supabase RLS
Build mobile-first screens for athletes and data-dense console screens for coaches with Tailwind CSS and shadcn/ui
Keep domain logic in clean, testable services; write unit tests and integration tests against a local Supabase
Deploy on Vercel and maintain infrastructure with Terraform
Monitor and triage production issues with Sentry
Use AI coding tools (e.g. Claude Code) daily to accelerate development
Collaborate closely with product and design; participate in code reviews
Senior:
own features from idea to production, make and document architecture decisions, and mentor others
Required Qualifications: Engineering:
3+ years commercial experience
Strong TypeScript and JavaScript fundamentals
Hands-on experience with React and Next.js (App Router), including the server/client component boundary
Solid SQL and PostgreSQL fundamentals: schema design, indexes, migrations
Experience with authentication and authorization in web apps
Understanding of Git workflows, CI/CD pipelines (GitHub Actions), and code quality tools (ESLint, Prettier)
Comfortable working with automated tests and code reviews
AI Mindset & Tooling:
Regularly uses AI-assisted development tools (e.g. Claude Code)
Reviews AI-generated code critically and knows when not to trust it
Uses AI for real productivity gains, not just experimentation
Product & Collaboration:
Understands the \"why\" behind features, not just the \"how\"
Cares about UX, especially on mobile
Comfortable working closely with product and design stakeholders
Good English communication skills (written and spoken)
Nice-to-Have
Experience with Supabase and Postgres Row-Level Security
Experience with Clerk authentication
Terraform or other IaC experience
Tailwind CSS and Radix UI / shadcn component libraries
PWA and mobile web experience (iOS Safari, installability)
Monorepo tooling (pnpm, Turborepo)
Exposure to observability tools (Sentry, product analytics)
Interest in sports, coaching or fitness products
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Mid Fullstack Engineer in Kraków – pracodawca: Appliscale
Appliscale to doskonały pracodawca, który oferuje dynamiczne środowisko pracy w sercu Krakowa, sprzyjające innowacjom i współpracy. Nasza kultura pracy opiera się na otwartości, wsparciu oraz ciągłym rozwoju pracowników, co pozwala na zdobywanie nowych umiejętności i awans w ramach organizacji. Dodatkowo, praca nad projektami związanymi z AI i ML w branży gier daje unikalną możliwość wpływania na przyszłość technologii w ekscytującym i rozwijającym się sektorze.
