Full Stack Engineer

Antler; Kraków; On-site; PLN 120,000 - 160,000; Full time

Job summary

Antler in Kraków, Poland, is seeking a Full Stack Software Engineer to help build an essential trust layer in modern software development. The role requires someone who can deploy code daily, engage directly with users, and contribute to training AI agents to improve software testing.

The ideal candidate will have experience in producing AI features and a full-stack background. Join Antler to influence the future of autonomous software testing.

Qualifications

• Experience shipping AI features in production.
• Background in building products from 0 to 1.
• Ability to adapt and thrive in chaotic environments.

Responsibilities

• Deploy software daily and communicate with users to shape the product roadmap.
• Design and train AI agents for testing that learn and adapt in real time.
• Own the entire software stack from commit to production.

Skills

AI/LLM fluency

Python

TypeScript

Cloud infrastructure

Frontend and backend development

Job description

Change Software Forever

Most engineering roles build software nobody fully trusts. This one builds the trust layer itself. AI is making engineers dramatically more productive. The problem is nobody fully trusts what AI ships.

Why this matters now

AI is rewriting how software gets built. But shipping still breaks on testing. Engineering leaders are desperate to release faster without dropping quality, and they can't get there with manual QA or brittle test automation.

Here's the bigger shift: as AI writes more of the code, the bottleneck moves from generating software to trusting it. Nobody owns that trust layer yet. Duku is building it, autonomous agents that simulate real users, catch critical failures before production, and self-heal as the product evolves.

Backed by experienced operators and investors, we're building what we believe will become a core layer of the modern software stack. We're looking for an exceptional Full Stack Software Engineer to help build it. Not someone to maintain a codebase. Someone to define one.

What You’ll Do

• Ship fast, learn faster: We deploy daily, not monthly
• Talk to users, shape the roadmap: Sit in the trenches with founders on calls that define what we build
• Train AI agents: Design LLM-powered testers that explore, learn, and adapt in real time
• Own the stack: Python, TypeScript, cloud infra, from commit to production
• Turn prototypes into production: Run real experiments on models, embeddings, and retrieval pipelines

What We’re Looking For

• Relentless drive: You execute fast, adapt faster
• Startup scar tissue: You’ve shipped product with no safety net
• Fluency with AI/LLMs: LangChain, vector stores, prompt engineering
• Full-stack firepower: Frontend, backend, infra, no silos
• Product obsession: You care more about outcomes than outputs
• Experimental instinct: You build - test - learn - repeat

Ideal Background

• Shipped AI features in prod
• Built something from 0 to 1
• Thrived in chaos with high ownership

Why This Matters

Software is accelerating. QA hasn’t kept up. Autonomous testing is inevitable, and we’re building it.

Five years from now, every high-velocity team will rely on AI agents like ours to ship faster, safer, and smarter.

Join now, and help make that future real, before someone else does.