As an indie publisher, I try to keep as much of a project in-house (read: DIY) as possible. The cover is one exception to this, and proofing is another.
Don’t get me wrong. I always proof my work. In fact, I create a style guide for each series so that I am consistent in how I represent things like dates, titles, song names, and so forth.
But even if I think my text is pretty clean after proofing it, I will never be able to catch all of my mistakes. Common culprits are missing words, extra words, and homophones. Again, I’m blessed to know someone who combs through the entire book, including front and back matter, to mark up what I miss. (Thanks, Dusty!)
Once I get the edits back, it takes me a couple of hours to update the paperback and e-book files.