When I first joined the workforce some twenty plus years ago, I wanted to be a systems administrator, or sysadmin as it has come to be aptly called. I had tinkered with our family PC for years, taking it apart, meeting with BBS admins buying their old RAM - it was glorious.

What is defect leakage? The short answer is that it is a bug that got past the entire team, and any test suites that are in place, winding up in production where users could be impacted.

Performance is an indication of the responsiveness of a system to execute any action within a given time interval, while scalability is the ability of a system either to handle increases in load without impact on performance or for the available resources to be readily increased.