Founding Full-Stack Engineer
Boost your chances before you apply.
WhyHireWrong?
Frankfurt
Summary
You will build and ship end-to-end SvelteKit applications while managing backend endpoints and database schemas. You are expected to own the product's UI/UX and performance while debugging production issues across the full stack.
Job Description
An early-stage, pre-launch startup, built by experienced venture builders, needs a Founding Frontend Engineer before launch. Pre-launch timelines are tight. This is an urgent hire.
The Role
Radical ownership of the product's UI/UX, working directly with the founder. High autonomy on approach and speed, paired with hands-on execution: shipping frontend features personally and building backend endpoints when the product needs it. No rigid process, no mandatory code review, blunt feedback culture.
Responsibilities
-
Build and ship SvelteKit applications end to end: routing, load functions, server-side rendering, form actions, and client-side state management.
-
Write component-level TypeScript with strict typing; no any as a default, and no unchecked casts to bypass the compiler.
-
Implement responsive, accessible UI with Tailwind CSS, including custom design systems and component variants, not utility classes copied from templates.
-
Build and expose REST or RPC endpoints in Fastify, including request validation (schema-based), error handling, and auth middleware.
-
Write and modify Postgres schemas: design tables, write and roll back migrations, and write raw SQL or use a query builder (Drizzle, Kysely, or Prisma) for non-trivial queries.
-
Own performance on the frontend: bundle size, hydration cost, load waterfall, and Core Web Vitals.
-
Set up or maintain CI/CD for a Node.js/SvelteKit app: build, lint, type-check, deploy.
-
Debug production issues across the full stack without handing off to a backend specialist.
Requirements
-
4+ years of professional frontend engineering, with at least 1-2 years using SvelteKit specifically. Deep, verifiable experience in another modern reactive framework (React, Vue) is acceptable only if paired with proof of fast ramp-up on Svelte.
-
Strict TypeScript: comfortable with generics, discriminated unions, and typing complex API responses. Can explain, without hesitation, why any is a problem and how to avoid it.
-
Working knowledge of Fastify specifically, or deep equivalent experience in another Node.js framework (Express, Hono, NestJS) with fast ramp-up expected on Fastify's plugin and hook system.
-
Hands-on Postgres skills: schema design, indexing basics, writing and reverting migrations, and diagnosing slow queries with EXPLAIN. Comfortable in the psql CLI, not only through an ORM GUI.
-
Tailwind CSS in production: custom theme configuration, component abstraction, and responsive design without excessive utility duplication.
-
Public GitHub profile with commit history that verifiably backs the stack above, or a live, functioning product built end to end that can be tested directly.
-
Able to walk through a real production incident or bug you fixed across both frontend and backend in the same session.
-
Based in Europe, working remotely, with significant working-hours overlap with a founder-led team.
Not a Fit If
-
No public GitHub profile or live shipped product demonstrating this exact stack.
-
Frontend-only background with no working knowledge of backend CRUD, API design, or SQL.
-
Has only used an ORM and never written raw SQL, or cannot explain what a migration does.
-
Loose TypeScript usage: any everywhere, no shared types between frontend and backend, no type safety across the API boundary.
-
No experience with schema validation, error handling, or auth middleware on a real backend service.
-
Exclusively enterprise background with narrow, siloed scope and no end-to-end product ownership.
Good to Have
-
Ex-founder or entrepreneurial background.
-
Side projects shipped for paying clients, with real users and real uptime requirements.
-
Direct production experience with SvelteKit, Tailwind, and Fastify together, not just individually.
-
Experience setting up a project from zero: repo, CI, hosting, database, auth.