Grzegorz Piwowarek
Owner at Bound
Warsaw, Masovian Voivodeship, Poland
Summary
🤩
Rockstar🎓
Top SchoolGrzegorz Piwowarek is a hands-on software engineering leader and founder with 11 years of experience specializing in distributed systems, reliability, and developer experience. He advises and trains teams as the owner of 4Comprehension while shaping event-driven architecture at Bound and previously engineered cloud-native systems at Hazelcast and Casumo. A prolific speaker and mentor—having delivered 140+ talks and 80+ workshops—he blends deep low-level Java and Go expertise with practical CI/CD, observability, and scalability work. His open-source contributions touch notable projects like GraalVM and Testcontainers and he leads the Vavr functional Java library, reflecting a commitment to cleaner APIs and runtime robustness. Pragmatic and detail-oriented, he’s solved thorny issues from GraalVM class-initialization quirks to 3 a.m. race conditions in production. Based in Warsaw, he combines engineering craft with developer tooling and process improvements that speed delivery without sacrificing correctness.
11 years of coding experience
14 years of employment as a software developer
Bachelor of Science (BSc), Computer Science, Bachelor of Science (BSc), Computer Science at Warsaw University of Technology
English, Polish
Stackoverflow
13,404reputation
3.4mreached
197answers
22questions
java
top-1%
sorting
top-5%
lambda
top-5%
arraylist
top-5%
kotlin
top-1%
Github Skills (42)
kotlin10
unit-testing10
caching10
docker10
postgresql10
graalvm10
testing10
hazelcast10
distributed-systems10
dockers10
java10
javas10
junit10
aot10
spring-boot10
Programming languages (20)
Github contributions (5)
eugenp/tutorials
Jun 2016 - Dec 2022
Getting Started with Spring Boot 3:
Role in this project:
Back-end Developer
Back-end DeveloperContributions:23 reviews, 496 commits, 2596 PRs in 6 years 7 months
Contributions summary:Grzegorz primarily contributed to the Java-based back-end code, addressing concurrency issues, adjusting APIs, and refactoring code. The commits demonstrate a focus on improving existing functionalities and resolving bugs. Specifically, the user worked on enhancing concurrency within the core-java-modules, updating dependencies like guava and fixing thread-related problems. Additionally, the user refactored MongoDB-related code, adjusting it to a non-null MongoClient API and removing redundant constructors.
spring-bootspring-security-oauthsecurityauthenticationsecurity-oauth
hazelcast/hazelcast
Dec 2019 - Oct 2022
Hazelcast is a unified real-time data platform combining stream processing with a fast data store, allowing customers to act instantly on data-in-motion for real-time insights.
Role in this project:Back-end Developer
Back-end DeveloperContributions:44 reviews, 73 commits, 114 PRs in 2 years 10 months
Contributions summary:Grzegorz contributed to the Hazelcast project by addressing a range of issues, including code improvements and bug fixes. They refactored code to use bulk operations for efficiency, corrected typos to improve code readability, and removed unnecessary dependencies. The user also corrected XML schema locations, replaced StringUtil constants, and updated various client and member configurations.
computationstream-processingbigtablereal-timestreaming-data
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