Open to opportunities

Krystian Graczyk

@krystiangraczyk

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Senior backend and full-stack engineer scaling cloud-native systems for millions of users.

Poland

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What I'm looking for

I’m looking for a team where I can lead backend and full-stack architecture, build distributed microservices on cloud infrastructure, and continuously improve reliability and performance through system design, CI/CD, and code reviews.

I’m a Senior Software Engineer with 8+ years of experience designing, building, and scaling high-performance backend systems and cloud-native applications. I focus on distributed systems, microservices, and API design to deliver scalable products used by millions of users.

Across my roles, I’ve led engineering initiatives that materially improved reliability and performance. At Allegro, I improved API response time by 35% using database optimization and caching, designed scalable microservices for high-volume transactions, and built CI/CD pipelines reducing deployment time by 60%.

At EPAM Systems, I refactored legacy systems into microservices, improving throughput by 40%, reduced infrastructure costs by 20% through cloud migration to AWS, and implemented monitoring/rollback systems that reduced downtime by 30%. I also collaborated with DevOps teams to improve release speed by 50%.

I also bring strong full-stack delivery and automation experience. At Capgemini, I developed scalable web applications with React and Node.js, improved frontend performance by 50% through code optimization and lazy loading, and built internal dashboards/automation tools that reduced manual processing by 40%. I’m proactive about mentoring engineers and driving architecture decisions across teams.

Experience

Work history, roles, and key accomplishments

Senior Software Engineer

Allegro

Aug 2023 - Nov 2025 (2 years 3 months)

Led backend and full-stack development for high-traffic e-commerce systems used by millions, improving API response time by 35% via database optimization and caching. Built scalable microservices and CI/CD pipelines that reduced deployment time by 60%, while mentoring junior developers.

TypeScript React Next.js PostgreSQL Redis AWS Docker Kubernetes CI CD

Software Engineer II

EPAM Systems

Jun 2021 - Jul 2023 (2 years 1 month)

Built enterprise applications and refactored legacy systems into microservices, improving throughput by 40%. Reduced infrastructure costs by 20% with AWS migration, cut downtime by 30% with monitoring and rollback, and increased release speed by 50% in collaboration with DevOps.

NestJS React AWS MongoDB PostgreSQL Docker Microservices REST APIs Jenkins

Full Stack Engineer

Capgemini

Jul 2019 - May 2021 (1 year 10 months)

Developed scalable web applications using React and Node.js, building internal dashboards and automation tools that reduced manual processing by 40%. Designed REST APIs, integrated third-party services, and improved frontend performance by 50% through code optimization and lazy loading.

JavaScript React MySQL MongoDB REST APIs Performance Optimization

Junior Software Engineer Intern

IBM

Jun 2018 - Jun 2019 (1 year)

Assisted in developing internal tools and enterprise applications, improving workflow automation efficiency by approximately 20%. Supported debugging and optimization of legacy systems, reducing processing time by 15%, and contributed to documentation and testing to improve system reliability and maintainability.

Java Spring Boot SQL Git Linux Unit Testing Debugging Distributed Systems