Senior .NET Developer (Payments/BLIK)

Quick Facts

• Role: Senior .NET Developer (Payments/BLIK)
• Collaboration: B2B contract
• Budget: 135–155 PLN/h net + VAT
• Work mode: Highly flexible/remote; required office presence in Łódź or Warsaw 1 day every 2 weeks
• Employment: Full-time, long-term contract

Description

You will join a team working on a key payments area for BLIK, building and maintaining event-driven services that run on Kubernetes.

The work spans asynchronous backend processing and classical API development; React/fullstack experience is a major plus.

Responsibilities

• Core development: build, evolve, and maintain backend applications and services using .NET 8.0, Web API, and MS SQL.
• Event-driven architecture and integration: design asynchronous business processes and connect data via Kafka and IBM MQ; integrate with external systems including SSIS.
• Cloud-native ecosystem: work with microservices and containerized services on Kubernetes (K8s) and Docker.
• Quality and automation: write unit and e2e tests, and use tools such as SonarQube within CI/CD pipelines.
• Business collaboration: communicate directly with stakeholders, including the business client and external vendors.

Requirements

• At least 5 years of commercial backend experience in C#, with strong focus on MS SQL.
• Practical expertise in the .NET ecosystem (especially .NET 8.0), Entity Framework, and Web API.
• Strong understanding of orchestration, containerization, and DevOps processes (Kubernetes, Docker, Azure DevOps, Jenkins, TeamCity).
• Hands-on experience with Kafka, IBM MQ, Redis/KeyDB, and SSIS.
• Excellent communication skills, delivery orientation, and ability to work fast in complex service architectures.
• Nice to have: Fullstack experience with React.

Benefits

• Influence on stability and development of critical payments services (BLIK) processing large financial transaction volumes daily.
• Long-term stable B2B cooperation with a clear budget.
• Benefits: Multisport card, private medical care, insurance.