Mariusz Sołtysiak
Staff Software Engineer at SumUp
Lodz Metropolitan Area Poland
Summary
👤
Senior🎓
Top SchoolMariusz Sołtysiak is a Staff Software Engineer with over 15 years of hands-on experience building and evolving backend systems, currently driving architecture, reliability, and best practices at SumUp from Lodz, Poland. He blends pragmatic craftsmanship with a strong focus on observability, extensibility and event-driven design, having led migrations to Java/Kotlin, PostgreSQL, Kafka, gRPC and Kubernetes. Beyond coding, he shapes hiring, mentoring, and cross-team knowledge sharing—regularly bringing Kotlin expertise into PHP-oriented squads and running initiatives like risk assessment and event storming. Comfortable as both a technical leader and a bridge to the business, he has a track record of refactoring legacy systems into maintainable modular platforms. An early freelancer and full-stack developer, he keeps a practical, product-oriented lens on engineering trade-offs.
11 years of coding experience
16 years of employment as a software developer
Master of Engineering - MEng, Information Technology, Master of Engineering - MEng, Information Technology at Wroclaw University of Science and Technology
English, Polish, German, Russian
Github Skills (75)
allegro9
soap-api8
vulnerability-scanners8
security8
amazon-s38
java8
vulnerability8
devsecops7
golang7
vulnerability-detection7
source-engine7
junit7
k8s7
kotlin-multiplatform7
vulnerabilities7
Programming languages (7)
Github contributions (5)
marrek13/kotenberg
Nov 2023 - May 2026
Contributions:18 releases, 8 reviews, 71 PRs in 2 years 5 months
Shoplo/bonapitit-bonanza-php-sdk
Sep 2017 - Jul 2018
PHP SDK for Bonanza Marketplace and its "Bonapitit" REST API.
Contributions:5 releases, 35 commits, 2 PRs in 10 months
phprestrest-api
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