Principal Backend Engineer

• Bachelor’s degree in Computer Science, Engineering, or related field.
• 15+ years of applied experience as an API engineer.
• Strong expertise in API design , architectural artefacts, and low-level designs.
• 10+ years of engineering experience in back-end microservices, application security, and middleware.
• Proficiency in Java (Go and Rust are a plus), JVM tuning, and performance optimization.
• Expertise in microservices, Spring Boot, Docker, Kubernetes, service mesh .
• Experience with Kafka , cluster configuration, and data streaming.
• Knowledge of monitoring tools (Splunk, Grafana, Prometheus) and DevOps practices .
• Familiarity with cloud environments , VPC, identity and access management, and Linux-based infrastructure.
• Strong SQL and distributed database knowledge.
• Experience in financial services or payment systems is an advantage.
• Excellent leadership, mentoring, and communication skills.
• Ability to work independently, manage priorities, and thrive in a dynamic environment.

Joining this project you’ll become part of Mindbox – a tech-driven company where consulting, engineering, and talent meet to build meaningful digital solutions. We’ll back you up every step of the way, accelerate your development, and ensure your skills make a difference.  

At Mindbox we connect top IT talents with technology projects for leading enterprises across Europe.  

We are looking for a Senior API Engineer / Technical Lead to provide engineering expertise for our Future State Architecture. You will play a key role in designing and developing best-in-class payment processing solutions, ensuring scalability, resilience, and compliance with global standards. This role involves technical leadership, architecture guidance, and hands-on development in a highly collaborative environment.

Sounds like your kind of challenge? 

What you get in return

• Flexible cooperation model – choose the form that suits you best
  (B2B, employment contract, etc.)
• Hybrid work setup – 3 days / week from office in Kraków
• Collaborative team culture – work alongside experienced professionals eager to share knowledge 
• Continuous development – access to training platforms and growth opportunities 
• Comprehensive benefits – including Interpolska Health Care, Multisport card, Warta Insurance, and more 
• High quality equipment – laptop and essential software provided 

,[Deliver engineering expertise for Future State Architecture, producing best-in-class payment processing capabilities., Create high-quality artefacts that set the standard for the team, ensuring quality gates and robust test scripts., Design, code, test, debug, and document programs as required., Provide architecture guidance to developers based on best practices and global standards., Lead and mentor team members, fostering technical excellence and innovation., Partner with DevOps teams to enable automated infrastructure delivery and CI/CD pipelines., Resolve architectural and development blockers, ensuring timely delivery., Conduct feasibility studies, cost/benefit analyses, and prepare technical specifications., Ensure compliance with all relevant controls and standards., Stay up-to-date with emerging tools, technologies, and cybersecurity regulations.] Requirements: Degree, API, Backend, Microservices, Security, Java, Go, Rust, JVM, Spring Boot, Docker, Kubernetes, Kafka, Splunk, Grafana, Prometheus, DevOps, Cloud, VPC, SQL Additionally: Sport Subscription, Private healthcare, Life insurance, Training budget, Small teams, Free coffee, Free snacks, In-house trainings, Modern office, No dress code.