Half a work day MTTR?!
I have a really strong reaction to that, and it’s not positive. Do not put yourself on my calendar without asking me, period. If you have a deadline for when you need something done by, then communicate with me and ensure that we can meet that goal.
Expecting other people to drop what they need to get done in a ~4 hour window and do a task for you is just asking for trouble, especially if you also expect your coworkers to focus and accomplish complicated tasks.
I don’t think that is completely unrealistic for given small reviews and the right team. At my current company, we have a pull request slack channel that we post to. Most PRs are reviewed in less than an hour. We are a smallish team with < 20 developers on our stack. I can see how for smaller teams that expectation could be more challenging. But we tend to review other people’s code quickly because we like it when our code is reviewed quickly.
That’s a very reasonable reaction in an environment where individuals own their work/outcomes.
It’s a quite reasonable request, however, in an environment where a close-knit team choose to share ownership of work & outcomes. I’ve only worked in one such environment in my career (so I know they can exist but they don’t seem common).