About this role
As Principal Software Engineer, you'll work directly with the Head of FinTech Engineering and business leadership, translating critical business goals - new product lines, regulatory deadlines, growth targets - into architecture decisions and roadmap input. You'll be the final word on cross-domain technical questions that no single team or Staff Engineer can resolve alone.
→ Hybrid working model: preferably 1 day per week in the Warsaw or Cracow office.
Responsibilities:
Serve as the single cross-domain technical authority, arbitrating architecture decisions across Payments Core, Merchant, and Consumer platform areasPartner directly with the Head of Engineering and business leadership to turn business strategy into technical roadmap inputAuthor Architecture Decision Records (ADRs) and RFCs for organisation-wide decisions, with reasoning accessible to both engineers and business stakeholdersOwn the agentic engineering harness at an organisational level — design, instrument, and continuously improve AI-assisted engineering workflows based on real production dataIdentify and drive the adoption or deprecation of patterns across all teams, building the case and sequencing change without direct authorityMentor Staff Engineers and Engineering Managers on architecture craft, technical communication, and agentic tooling 10+ years in software engineering, including 5+ years in cross-team technical leadership or architecture authority5+ years designing distributed payments or fintech systems3+ years of agentic/LLM engineering in production — shipped systems, not theoretical patternsDeep knowledge of distributed systems architecture: event sourcing, CQRS, domain events, saga patternExperience designing APIs at an organisational boundary level — REST, async, and event-based contractsStrong grasp of database trade-offs (relational, time-series, document, ledger-style) and cloud architecture evaluation (AWS/GCP/Azure) at organisation scaleHands-on experience with multi-agent orchestration, tool-use patterns, context management, and evaluation harnesses for AI-assisted engineering workflowsExcellent technical writing for mixed audiences — ADRs and RFCs that work for engineers and business leadership alikeEnglish proficiency at B2 or aboveUniversity degree in Computer Science, IT, or a related fieldNice to have:
3+ years in platform or internal developer tooling engineering1+ years of agentic/LLM system design experiencePCI DSS / PSD2 architecture compliance experience from the design phaseBNPL or lending domain architecture experienceOpen-source contributions or external technical publishingExperience building or scaling an internal developer platformFormal mentorship of Staff-level or EM-track engineersPolish language skills Opportunity to work in a diverse, international, and cross-functional environment, along with leading experts. You work and learn from a senior leader and their leadership team, expanding your experience and exposure in the e-commerce and logistics industries. InPost is a growing company that offers its people an increasing number of opportunities in several locations in Europe. Fulfilling careers with a range of benefits for people and investing in providing training opportunities for their development. You will feel a part of the InPost community that makes an impact on sustainability, convenient deliveries, and the circular economy every day. Excellent working environment and flexible hoursWe offer B2B type of contract