Bolek Ziobrowski
Senior Software Engineer at Tsuga
Wrocław, Lower Silesian Voivodeship, Poland
Summary
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Rockstar🎓
Top SchoolBolek Ziobrowski is a Senior Software Engineer with seven years of focused experience building high-performance back-end systems and databases, currently based in Wrocław, Poland. He has worked as a core database engineer on QuestDB and contributed to Apache Pinot, improving real-time OLAP query engines and adding application-level query quotas—work that underscores his expertise in query performance and robust error handling. A self-described performance geek and database enthusiast, Bolek has practical experience tuning type handling, float/double parsing, and SQL compiler behaviors in production-grade time-series systems. His career spans startups and enterprise roles, including hands-on architecture and ownership experience from running RORK to senior engineering positions at Tsuga and StarTree. Colleagues rely on him for pragmatic solutions to scaling and query-throttling challenges, and his open-source contributions show a preference for impactful, low-level improvements rather than surface features. He holds a Master's degree in Computer Science from Wrocław University of Science and Technology and brings a blend of deep technical craft and product-minded delivery.
7 years of coding experience
17 years of employment as a software developer
Master's degree Computer Science, Master's degree Computer Science at Wrocław University of Science and Technology
English, Polish
Stackoverflow
375reputation
2kreached
17answers
6questions
Github Skills (25)
timeseries-database10
apache-pinot10
back-end-development10
query-optimization10
time-series10
java10
javas10
sql10
database-design10
error-handling10
data-structure9
apidoc9
api9
data-structures9
hashtable9
Programming languages (4)
Github contributions (5)
questdb/questdb
Nov 2021 - Jan 2023
QuestDB is a high performance, open-source, time-series database
Role in this project:
Back-end Developer & Database Engineer
Back-end Developer & Database EngineerContributions:517 reviews, 64 commits, 164 PRs in 1 year 2 months
Contributions summary:Bolek contributed to the QuestDB time-series database by implementing fixes for double and float parsing, and for SQL-related issues. These changes involved modifying Java code within the core repository, specifically related to the handling of data types and queries. Additionally, the user worked on features related to the SQL compiler, including specifying index block sizes and enhancing type compatibility checks.
simdfinancial-analysisgrafanatime-seriestsdb
apache/pinot
Aug 2024 - Mar 2025
Apache Pinot - A realtime distributed OLAP datastore
Role in this project:Back-end Developer
Back-end DeveloperContributions:165 reviews, 22 PRs, 177 comments in 7 months
Contributions summary:Bolek primarily focused on improving the Apache Pinot query engine's functionality and robustness. Their work involved enhancing query option validation and error handling, specifically addressing limitations in the `numGroupsLimit` parameter. They also contributed to the implementation of application-level query quota mechanisms within the broker, enabling query throttling based on application name. Furthermore, the user added support for the `text_match` transform function, expanding the capabilities of text-based querying.
realtimedata-streamolapapachedatastore
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