Senior Software Engineer (Hybrid - Poland)

Job description

With millions of wallets created and a global audience, is one of the world's leading crypto content and onboarding platforms. We are now starting something new, from a blank repo in Rust , and we are early enough that the architecture is still being decided. Join us in bringing crypto to the next billion users. Location: Warsaw (remote for first months, then hybrid) Key Responsibilities Design and build the core services behind the product: APIs, data models, integrations, and make the architectural calls that will shape the system for years Own significant pieces of the product end-to-end, from design through production, including on-call ownership and incident response Partner directly with Product and Design to shape requirements, pushing back where needed so what gets built holds up under real-world load Set the technical standard for the codebase: write code others can maintain, and hold the team to that bar through reviews and mentorship Drive architecture and technical decisions while the foundations are still being laid, and bring the judgment to know which decisions are expensive to reverse Mentor other engineers and help level up the team's practices around testing, instrumentation, and code quality What We Are Looking For: Required 5+ years of professional experience, with a track record of owning systems in production, not just shipping features Strong Rust, Go, Java or Kotlin; production in Rust is a must Proven experience designing REST APIs at scale; contracts, versioning strategy, and the judgment to know what will and will not age well Deep experience with AWS or equivalent, containers, and CI/CD, including having built or hardened these systems, not just used them Fluent with AI coding tools like Claude Code, with strong judgment on when to trust, and when to override, their output Experience mentoring engineers and/or leading technical initiatives Clear written and verbal English, and a self-driven work style BS in Computer Science or equivalent experience Nice to Have Payment rails (SEPA, SWIFT, ACH) or card issuing Regulated fintech: PSD2, KYC/AML, PCI DSS Crypto custody, on-chain settlement, stablecoin flows Monitoring and analytics tools (Sentry, New Relic) Experience setting technical direction or architecture for a product from its earliest stages Solid blockchain fundamentals: ERC20, RPC nodes, UTXO vs account models Why Join Us Competitive salary and benefits Build a new product from the ground up, not maintain someone else's Room to grow in a fast-moving global organization Shape the architecture and technical culture of a fast-moving global organization One of the most recognized names in crypto Flexible, modern environment