Stewart currently works for IBM in the Linux Technology Center on OPAL, the OpenPOWER Abstraction Layer - open source firmware for POWER. He currently finds it weird when you don't have the source code to your firmware.

Previously, Stewart worked for Percona as Director of Server Development with a deep background in database internals including MySQL, MySQL Cluster, Drizzle, InnoDB and HailDB. He was one of the founding core developers of the Drizzle database server project which he worked on at Sun Microsystems and later Rackspace. He started in the database world at MySQL AB working on MySQL Cluster.