Jan 2019 – Present · 7 yrs 5 mos

• https://trino.io/
• https://github.com/trinodb/trino
• https://github.com/trinodb/trino/graphs/contributors :)

Nov 2017 – Jul 2024 · 6 yrs 8 mos · Warsaw, Mazowieckie, Poland

• Performance engineering at Starburst

Jul 2014 – Aug 2017 · 3 yrs 1 mo · Warsaw, Masovian District, Poland

• Working on Presto database and surrounding ecosystem:
• analyzer/planner (SQL compatibility, type system) improvements;
• optimizer (cbo, join enumeration, statistics);
• new data types support: decimal, char;
• performance and memory improvements (fast decimal type, plan optimizers, execution optimizations);
• advanced query statistics reporting;
• RE2J-TD library: high performance RE2 port to java;
• Tempto: flexible SQL database testing framework with declarative requirements;
• Benchto: benchmarking framework for cluster scale databases;
• tests automation infrastructure with Docker, Jenkins, Vagrant, etc;
• in-depth code reviews, community support and mentoring younger team members
• various other Presto features.

Feb 2014 – Jul 2014 · 5 mos · Warsaw, Mazowieckie, Poland

• Worked on SQL on Hadoop technology. Hadapt was acquired by Teradata. Some components I worked on:
• transaction subsystem;
• indexes;
• performance benchmarks;
• Hadapt-Teradata connectivity.

Aug 2012 – Feb 2014 · 1 yr 6 mos · Warsaw Metropolitan Area

• Working in a team on various projects:
• a currency exchange service (banking connectivity, database and services layer). For the project I have developer a novel Linux desktop automation tool based on JNA and low level Linux features. Technologies: Core Java, Spring, Hibernate, ORM, PostgreSQL, Apache CXF, Freemarker, Web Services, PKCS, FOP, Javascript, jQuery, Bootstrap, Linux, JNA.
• a project for books reading on mobile devices (iOS, Android, Windows Phone). For the project I have developed a very algorithmic jQuery layout engine for a high quality mobile eBooks reader. The quality is comparable to major brand apps (e.g Google Books, Kindle). The app is installed on hundreds of thousands mobile devices.
• Technologies: jQuery, Javascript, Algorithms, C#, Java, Windows Phone, Android, iOS.
• an audiobooks watermarking tool, which would be resistant to audio manipulation attacks (e.g. compression, speedup).
• Technologies: Python, SciPy, Numpy, FFT, Multiprocessing.
• a Vehicle Tracking System for a major car manufactured. I work on both frontend app (iOS) and backend (Spring, J2EE, Hibernate).
• Technologies: Java, Spring, Hibernate, ORM, PostgreSQL, JSP, Javascript, iOS.

Sep 2011 – May 2012 · 8 mos · The Randstad, Netherlands

• I was working on a project related to virtual infrastructure networks and cloud computing SLAs. The project involved extending OpenNebula cloud stack with dynamic networking capabilities (provisioning, creation, maintenance) both on virtual guest as well as physical hosts. Additionally, I performed network bandwidth experiments using low level kernel techniques. I was also Cluster & Grid Computing (Hadoop, JavaGAT) teaching assistant.

Nov 2010 – Apr 2011 · 5 mos · Zurich, Switzerland

• I worked on a data warehouse system and business data science project. My work involved designing and implementing of a data model and data loading processes (e. g. designing database structure and ETL processes). I also applied statistical analysis on gathered and aggregated data (using the R project). The purpose was to explore business data correlations that would enable IBM to improve support centers efficiency.

Oct 2009 – May 2010 · 7 mos · The Randstad, Netherlands

• Part time job as Research Assistant for Prof. Andrew S. Tanenbaum. I was helping in development of Minix 3 operating system. My job involved C code fixes and analysis.

Feb 2009 – Apr 2009 · 2 mos · Warsaw Metropolitan Area

• I was working on a project aimed at integration of the web browser (based on the WebKit or Gecko engine) with the Set-Top Box device.

Jun 2008 – Sep 2008 · 3 mos · London Area, United Kingdom

• Our job (I was working along with a French colleague) was to create a GUI client – server application based on such technologies like the C++, XML, Javascript and internal Bloomberg systems.