Quality Control (abbreviated (QC) is one of those areas of the film industry that isn't glamorous but is nonetheless important to appreciate. QC is required before delivering to any broadcast or streaming network to ensure that your program meets all of the technical requirements to be broadcast or streamed. If your post process has gone smoothly and you've met your deadlines, you have plenty of time to deliver the material to an outside QC house for evaluation and time to fix any errors that might arise.
Unfortunately, very few projects keep to their post schedule. As a result, QC is often a rushed process, involving last minute requests to the QC house to stay up late and evaluate a project, providing fast fixes to QC errors in order to meet a deadline.