Software Engineer
Unknown
August 5, 2026 at 12:12 AM
← Careers
Full-time
We're looking for a Software Engineer to work across high-impact US and EU engagements. You'll build production-grade full-stack systems — from React frontends and REST APIs to cloud infrastructure and AI-integrated backends — with full ownership of the code you ship. This role is for engineers who move fast and take pride in clean, scalable work.
About Seyn
Seyn is an AI-native engineering firm headquartered in Zagreb, Croatia. We're building the operating layer where AI runs businesses — learning how they work, then automating them. Right now we do that through client work: custom AI solutions deployed in days, for companies that are done waiting. Every engagement moves us closer to the infrastructure we're actually here to build.
What you'll do
EUR 3,500 – 5,200 gross / month
Employment contract
EUR 10,000 – 30,000 / year
Equity grant or profit pool (estimated)
Apply now →
Or reach out directly at doris@seyn.so
Full-time
- Zagreb or Remote
- Mid to Senior
- Full-Stack
We're looking for a Software Engineer to work across high-impact US and EU engagements. You'll build production-grade full-stack systems — from React frontends and REST APIs to cloud infrastructure and AI-integrated backends — with full ownership of the code you ship. This role is for engineers who move fast and take pride in clean, scalable work.
About Seyn
Seyn is an AI-native engineering firm headquartered in Zagreb, Croatia. We're building the operating layer where AI runs businesses — learning how they work, then automating them. Right now we do that through client work: custom AI solutions deployed in days, for companies that are done waiting. Every engagement moves us closer to the infrastructure we're actually here to build.
What you'll do
- —Build and maintain full-stack applications across the entire product lifecycle — from database schema to pixel-perfect UI.
- —Own your code from design through deployment — accountable for quality, performance, and reliability in production.
- —Design and build RESTful APIs and backend services that are clean, well-documented, and built to scale.
- —Integrate AI capabilities into product features — LLM calls, structured outputs, AI-driven automation — working alongside AI Engineers to ship coherent systems.
- —Participate in agile ceremonies directly with US and EU clients — sprint planning, standups, retrospectives.
- —Use AI-augmented development tools daily as a force multiplier: code assistants, automated testing, documentation generation.
- —Instrument applications with logging and monitoring tooling; respond to production incidents with urgency and ownership.
- —4+ years of professional software engineering experience, with meaningful full-stack production work.
- —Strong proficiency in TypeScript or JavaScript (Node.js) on the backend and React or similar on the frontend.
- —Solid understanding of relational databases (PostgreSQL or similar), REST API design, and distributed system fundamentals.
- —Experience with testing (unit, integration, E2E) and a genuine belief that code review makes the team better.
- —Comfortable working with AI tools (Cursor, Copilot, Claude) as part of your daily workflow — curious and fast.
- —Strong written and spoken English — you will communicate daily with US-based teams and clients.
- —Bonus: experience calling LLM APIs from application code, working with structured outputs, or building AI-powered product features.
- —Experience with Python for backend services or scripting.
- —CI/CD pipelines (GitHub Actions, Jenkins) and containerisation (Docker, Kubernetes).
- —Cloud platform experience: AWS, GCP, or Azure.
- —Redis, RabbitMQ, or similar queuing and caching layers.
- —Work on production systems used by emergency services, global real estate companies, public safety infrastructure, and high-growth US tech companies.
- —AI-native culture — AI-augmented workflows are not optional here; they are how we work. You'll be trained, supported, and pushed to use AI as a core part of your daily process.
- —Seyn's founders previously exited Flow and Form, a software engineering firm acquired by Robin. You're joining a team that has done this before.
- —Competitive salary, flexible hours, remote-friendly.
EUR 3,500 – 5,200 gross / month
Employment contract
EUR 10,000 – 30,000 / year
Equity grant or profit pool (estimated)
Apply now →
Or reach out directly at doris@seyn.so