Founding Engineer at 0to9

0to9; Wrocław; On-site; PLN 180,000 - 300,000; Full time

Job summary

0TO9 is building a new banking venture in a stealth-like setup. You will contribute to a greenfield, on-site Wrocław engineering effort focusing on .NET backend and TypeScript frontend. The role emphasizes pragmatic, scalable architectures, security-first thinking, and rapid product iteration.

You will work in a small, autonomous team delivering prototypes quickly, shaping the platform as the first engineers to establish architecture, tooling, and best practices for a fintech product.

Qualifications

• Experience with building full-stack applications using .NET and TypeScript.
• Proficiency in designing scalable backend services and efficient frontends.
• Familiarity with cloud infrastructure and secure, observable deployments.

Responsibilities

• Prototype and ship working software with quick feedback from real users.
• Collaborate closely with product and business to shape technical decisions.
• Maintain clean, well-tested code with CI/CD pipelines and automated reviews.
• Ensure security, observability, and compliance across services.

Skills

Backend development

Frontend development

TypeScript

.NET

SQL

AWS

Docker

CI/CD

Security

Observability

Microservices

Testing

Tools

GitHub Actions

Datadog

CloudWatch

Secrets Manager

Job description

This Full time on site position offers great opportunities for career growth. Location: Wrocław, DO, PL.

About 0TO9

0TO9 is a bank for entrepreneurship, built by and for financial innovators. We provide infrastructure for entrepreneurs ready to start and scale the next generation of financial products and platforms. Founded in 2025, we're already 200+ co-workers across Europe, and growing fast. Our name reflects our mission: from zero to success, from idea to impact, from now to what's next.

The Venture

We're early and in stealth, so here's what we can say: it's a new banking business, separate from anything else in the group, aimed at a market we think is badly served today. The company is already led by a CEO. The customer, the product, and the wedge are what you'll help us find. What we're not doing is a hiring cycle to backfill a team. You're early enough that the first architecture calls, the first engineering culture, and a good share of the product thinking are genuinely yours.

How We Build This

We build on .NET and SQL on the backend and TypeScript on the frontend (React and Vue). Prior experience in these helps, but it isn't the bar - what matters is that you want to build in them. Agentic tools make an unfamiliar stack cheap to learn; they don't make an unwilling one work. The fundamentals below are what we can't teach you in the first month:

• Engineering standards loaded as a skill, so agents apply them automatically.
• A git-backed knowledge base that agents read and extend.
• Agent workflows that take a change from branch to reviewed PR.
• An automated reviewer in CI that counts as an approving review on a pull request. In a team of one, that last one matters.

We're not looking for someone curious about whether this works. We're looking for someone who already builds this way - and will push it further than we have.

What You Will Actually Do

Compress the distance between idea and working software: prototype, put it in front of real people, and let what you learn kill or grow it. Implementation is the fast part of this job; deciding what deserves to exist is the hard part. Sit close to the problem, not the backlog: you'll be in customer conversations and in the room where the business model gets argued about. We expect that to change your technical choices, not just inform them. Make fast, reversible decisions: simple, boring architecture that can be thrown away. We don't have scale yet, and pretending otherwise is the most expensive mistake available to us right now. Set how engineering works here: tooling, workflow, standards, guardrails - for whoever joins after you.

Technical Requirements

• Stack Backend: .NET and SQL.
• Frontend: TypeScript - React and Vue.
• Cloud & Infrastructure AWS-native: ECS/Fargate, S3, least-privilege IAM.
• Container fluency: build, ship, and debug in production.
• Security by default: WAF, encryption at rest and in transit.
• EU data residency: aware of why region matters (eu-north-1).
• Architecture Microservices & DDD: boundaries by domain, not layer.
• API/event-driven: no shared databases.
• Resilience patterns: retries, backoff, idempotency.
• Clean, SOLID code: safe for a human - or an agent - to extend.
• Delivery & Quality CI/CD fluency: GitHub Actions or equivalent.
• Test-driven habits: 80%+ coverage, no exceptions.
• Reviewable PRs: small diffs, no self-merges.
• Supply-chain hygiene: dependency & SCA scanning before ship.
• Observability & Security Structured logging & tracing: CloudWatch, Datadog, or equivalent.
• Zero hardcoded secrets: Secrets Manager or equivalent, always.
• Encryption everywhere: KMS at rest, TLS in transit.

Nice to Have

• .NET / TypeScript experience: you'll ramp faster.
• Coming from another ecosystem is fine if you're genuinely happy writing C#.
• Fintech / regulated-industry background: you'll ramp faster.
• Agentic tools as your daily driver: Claude Code, Cursor, or similar.

Who You Are

• Builder, not just coder: you've shipped real products (side projects count) and know the difference between "working" and "done."
• AI-native: you already lean on LLMs and agentic tools daily and are curious how far that can go - you see them as leverage, not a shortcut.
• Comfortable with ambiguity: you don't need a fully specified problem to start making progress.
• Business-minded: you can hold a conversation about unit economics, customer needs, or go-to-market - and let that shape your technical choices.
• Pragmatic generalist: deep specialization matters less than range and judgment; you can move across the stack as needed.

What Success Looks Like

Within weeks, not months, you've helped ship a working prototype we can put in front of real users. You've established a lightweight, AI-augmented way of building that lets a tiny team punch far above its weight. The founders trust you as a thinking partner, not just a pair of hands. Whoever we hire next inherits a codebase and a way of working that's simple, fast, and easy to build on.