Principal Software Engineer (Fintech)

Location: Hybrid in Warsaw or Cracow, Poland; preferably one day per week in the office

Company

Building a large-scale fintech platform from the ground up within an international e-commerce and logistics environment.

What you will do

• Act as the cross-domain technical authority for Payments Core, Merchant, and Consumer platform architecture.
• Translate business strategy, product expansion, regulatory deadlines, and growth targets into technical roadmap input.
• Author architecture decision records and RFCs for organisation-wide decisions.
• Own and improve the organisation-wide agentic engineering harness using production data.
• Drive adoption or deprecation of technical patterns across teams without direct authority.
• Mentor Staff Engineers and Engineering Managers on architecture, technical communication, and agentic tooling.

Requirements

• 10+ years of software engineering experience, including 5+ years in cross-team technical leadership or architecture authority.
• 5+ years designing distributed payments or fintech systems.
• 3+ years of production agentic or LLM engineering experience.
• Deep knowledge of distributed systems, including event sourcing, CQRS, domain events, and saga patterns.
• Experience with REST, asynchronous, and event-based APIs, database trade-offs, and cloud architecture across AWS, GCP, or Azure.
• English proficiency at B2 or above and a university degree in Computer Science, IT, or a related field.

Nice to have

• Platform or internal developer tooling engineering experience.
• PCI DSS, PSD2, BNPL, or lending domain architecture experience.
• Experience scaling an internal developer platform or mentoring Staff-level and EM-track engineers.
• Polish language skills.

Culture & Benefits

• Diverse, international, and cross-functional environment.
• Exposure to e-commerce, logistics, sustainability, convenient deliveries, and the circular economy.
• Flexible working hours and a hybrid working model.
• Training and development opportunities.
• B2B contract offered.