Senior Backend Engineer (FinTech)

Location: Hybrid, preferably 1 day per week in the Warsaw or Cracow office, Poland.

Company

Building an international fintech platform and core financial services for InPost's ecosystem at scale.

What you will do

• Design and build event-driven backend services for payment authorization, ledger management, settlement, and related financial processes.
• Develop scalable and resilient APIs with a focus on reliability, security, performance, and maintainability.
• Own the full software development lifecycle, including requirements, architecture, development, testing, release, production monitoring, and support.
• Design structured domain events and integrations across distributed systems while collaborating on roadmaps and technical direction.
• Investigate incidents, perform root cause analysis, and drive continuous platform improvements.
• Mentor engineers, conduct code reviews, and promote engineering best practices.

Requirements

• At least 5 years of backend software engineering experience using Java, C#/.NET, Rust, or Node.js.
• Hands-on experience designing and operating distributed systems and event-driven architectures.
• Experience delivering and maintaining production services, APIs, CI/CD pipelines, and observability solutions.
• Understanding of consistency models, saga patterns, idempotency, and outbox patterns.
• Practical experience with relational databases, preferably PostgreSQL.
• Experience with automated unit, integration, and contract testing.
• Daily use of AI-powered engineering tools such as GitHub Copilot, ChatGPT, Claude, or similar solutions, following engineering best practices.
• English proficiency at B2 level or higher.

Nice to have

• Experience in payments, fintech, or regulated environments.
• Production experience with Java and Spring Boot.
• Knowledge of Kafka or other streaming technologies.
• Familiarity with PCI DSS, PSD2, KYC/KYB, or risk decisioning systems.
• Experience with Docker, Kubernetes, cloud platforms, and Prometheus, Grafana, or OpenTelemetry.

Culture & Benefits

• Full-time contract of employment.
• Autonomous engineering environment focused on accountability and continuous learning.
• Opportunity to shape technical standards, mentor others, and influence platform evolution.
• Access to cloud-native technologies and event-driven architectures.
• Collaboration with experienced product, engineering, and business teams.