Macej is one of the MySQL Performance Team experts since July 2007. Aside from the regular consulting, he also does MySQL Server hacking, focusing on performance monitoring and scaling improvements.

Macej gained his experience working for several years as a systems administrator and lead MySQL DBA at Polish web portal INTERIA.PL (http://www.interia.pl/). His specialization was in the e-mail services built on FAMP, LAMP and other open-source technologies which were handling 10+ million users sending and receiving hundreds of millions of messages every day. Before joining Percona, Macej held the position of a systems architect with the responsibilities of designing and leading the implementation of scalable services for high volume traffic.