InPost Pay is seeking a Staff Software Engineer (Backend) to define the technical direction for one of our fintech platform areas—Payments Core, Merchant, or Consumer. The role will multiply team output through architecture clarity, engineering standards, and cross-team technical leadership, while evolving our agentic engineering harness in a data-driven fintech environment. You will own the evolution of fundamental technology decisions across your area and serve as the technical throughline between engineering, product strategy, and the broader architecture standards. This is a hybrid role with the preference for one day per week in the Warsaw or Krakow offices.

Responsibilities

Define and maintain backend architecture (domain boundaries, event contracts, state machine patterns, data consistency models, cross-service API design). Author Architecture Decision Records (ADRs) and RFCs to document reasoning and trade-offs. Evaluate technology trade-offs (databases, cloud services, message broker topology, consistency models for financial data). Own evolution of the agentic development harness—instrumentation, adoption measurement, and data-driven improvements. Drive org-wide technical change by identifying patterns, building a business case, and enabling adoption across teams without direct authority. Provide technical input into product strategy and mentor staff-level engineers through design reviews, pairing, and writing feedback.

Requirements

8+ years in software engineering, including 2+ years in cross-team technical leadership or architecture authority; 3+ years desig

About the role

InPost Pay is seeking a Staff Software Engineer (Backend) to define the technical direction for one of our fintech platform areas—Payments Core, Merchant, or Consumer. The role will multiply team output through architecture clarity, engineering standards, and cross-team technical leadership, while evolving our agentic engineering harness in a data-driven fintech environment. You will own the evolution of fundamental technology decisions across your area and serve as the technical throughline between engineering, product strategy, and the broader architecture standards. This is a hybrid role with the preference for one day per week in the Warsaw or Krakow offices.

Responsibilities

Define and maintain backend architecture (domain boundaries, event contracts, state machine patterns, data consistency models, cross-service API design). Author Architecture Decision Records (ADRs) and RFCs to document reasoning and trade-offs. Evaluate technology trade-offs (databases, cloud services, message broker topology, consistency models for financial data). Own evolution of the agentic development harness—instrumentation, adoption measurement, and data-driven improvements. Drive org-wide technical change by identifying patterns, building a business case, and enabling adoption across teams without direct authority. Provide technical input into product strategy and mentor staff-level engineers through design reviews, pairing, and writing feedback.