Senior Full-Stack Engineer (w/m/d)

TL;DR

Founding Engineer.
Build v1 -> v10. Join the early core team of experienced entrepreneurs (scaled to millions of users, $100m+ exits). Build the future of tax & accounting with AI. Own the backend and ship features end-to-end, influence the stack, and lay the foundations for scale. Grow into leadership as we expand across countries. Above-market pay + meaningful equity.

The opportunity

How taxation, accounting and payroll work today is a pain for everyone. Still every business must do it continuously. It is the backbone that our economy runs on.

Enabled through AI, we are turning this often-painful process into a radically simple experience for our customers, so they can focus on what matters to them: growing their business.

About us

We are a team of experienced entrepreneurs who have scaled businesses to 10s of millions of users, 10s of millions in revenue, multiple countries, and 9-digit exits - and we are just getting started. We are backed by leading venture investors and expanding rapidly.

The role

As an early Founding Engineer, you’ll be a core part of building and scaling Skalar. We are past the initial founding phase, but we are still very very early - meaning pretty much everything you touch will be greenfield building.

While we are providing a world-class professional service to our customers, technology is at our core and you will be an integral part of building it from scratch. Your work will be the driving force behind our revolutionary customer experience, enabled through AI, offering radical simplicity to our customers.

What you’ll own

• Build 0→1 and beyond with the founders: Ship major features and product lines end-to-end (spec → ship → measure).
• Core Architecture: Design and implement the APIs, data models and services that the product runs on — and ship the UI on top of them. Pragmatic architecture choices with high autonomy.
• Iterate fast: Ship v1 fast, iterate weekly with real user feedback.
• Leadership: Hire and mentor junior engineers (if interested); gain leadership experience as we grow.

Our tech context (greenfield)

• Prefer boring tech where it matters; innovate where it differentiates.
• Current stack (continually evolving): TypeScript end-to-end, Next.js (React) with server-side APIs, PostgreSQL, Vercel, …
• Most of the hard problems sit behind the API: data modelling for tax logic, integrations with third-party systems, and AI pipelines that have to be correct, not just plausible.
• You’ll have a strong influence on tech and product choices.
• Tooling budget for whatever makes you fast. No legacy, no yak‑shaving.

What you’ll bring

• 5+ years of professional experience building and operating web applications end-to-end, with strong TypeScript/Node fundamentals (Next.js, FastAPI, or comparable server frameworks; React on the frontend)
• A bachelor’s or master’s degree in computer science or a related field
• You have worked in a cross-functional team setup, are product-minded and like working in an agile startup environment
• Your centre of gravity is the backend — APIs, data modelling, integrations — and you're comfortable owning a feature through to the UI. Balanced full-stack profiles are equally welcome; what matters is that you can go deep on the server side.
• You have experience in deploying applications using containerization and orchestration tools (such as Docker)
• You have integrated AI already deeply into your daily coding tasks and don’t just use it for autocompletion
• Very good written and verbal communication skills in English (min. C1), German is a plus
• You have a valid work permit to work in Germany

What you’ll get

• Unique opportunity to join a company very early which you can shape
• Rapid growth path: Grow your career with the growing company
• Perfect environment to develop relevant skills in a world of AI
• Above-market compensation + Equity package, that has the potential to drastically gain in value

The process (fast, meaningful, no homework)

• Jump on an intro call with a recruiter
• Get to know a fellow engineer, virtually or in person (up to you)
• Meet our whole founding team during a final interview (in-person, ~3h, incl. live coding)