One metric I like to give my team is to have any new PR start a review in less than 15 minutes and be completed within 15 minutes. So, the longest you should wait is about 30 minutes for a review. That means teams either go "fuck it" and rubber stamp massive PRs -- which is a whole different issue -- or they take it seriously and keep PRs small to get their PRs reviewed in less than 30 minutes.
In most cases where I see responses like this, they're not surprised to wait hours or days for a PR review. In that case, it makes sense to go big, otherwise you'll never get anything done. If you only have to wait half an hour, max, for a PR review; the extra code churn is 1000% worth it.
As a developer, I want my PRs to actually be reviewed by my coworkers and to have issues caught as a second layer of defense, etc.
As a reviewer, I effectively stopped approving things I couldn't give at least a cursory, reasonable glance (and tried to encourage others to follow suit because if we're not reviewing things, why not just push directly to main).
As a consequence, I have:
* tried to review most things within like half an hour of their announcement
in the shared MR channel
* requested a pair programming session and offered to do a pair programming
session for any large and semi-or-fully automated refactoring session,
like running a linter or doing a multi-file variable rename
(the pair programmer immediately comments on and approves the MR when it
appears)
* tried to limit my PRs to approximately 400 lines (not a rigid rule)
There were some specific instances of people not liking the "you must pair program if you're going to touch 400 files in one PR" requirement; but otherwise, I would like to think those on my team liked the more regular PRs, more people doing the PRs, etc, that resulted from this and some healthy culture changes.
I would also like to feel like the more junior devs were more willing to say anything at all in the PRs because they could follow the change.
I’ve seen this and variations done by teams to implement the metric. Usually, the “biggest” friction comes from “how do we know a PR needs to be reviewed within the time frame?” To which I always want to answer: “you have a mouth, put noises through it.” Sigh, sometimes I miss the military… anyway, toxic behavior aside, this is usually the biggest thing. I have to remind them that they go get coffee or smoke at least every hour, but rarely at the same time; so maybe then might be a good time to just do a quick check for an open PR. Or turn on notifications. Or if it’s urgent, mention it in the dev team channel.
But yeah, it’s hard to get the culture rolling if it isn’t already in place nor has anyone in the company worked with a culture like that.
I'm all for low-latency reviews, but this target seems crazy: a perfect recipe for a lot of apparent activity for little actual progress. Maybe it depends on the project, but for a lot of projects 15 minutes of review time means you basically are only going to accept trivial changes.
As it turns out, most of the work that most developers do is updating or enhancing CRUD apps. There's already a plan and an intent that just needs to be typed out.
I've found 15-30 minutes to be plenty of time to review about a day's worth of code. It's enough time to process what the code is doing and iterate over the tests, in general.
Here's a scary thought: if something small takes 15-30 minutes to appropriately process ... how much longer do *large* changes take? Can someone keep all that in their mind that whole time to comprehend and process a huge change?
> 15 minutes of review time means you basically are only going to accept trivial changes.
Um, yes. This is 100% the point. There is no amount of refactoring, bug fixing, or features that cannot be expressed as a chain of trivial changes.
What you usually see happen is that instead of spending a week experimenting with 15 different refactors, is that an engineer opens a PR with what they think they're going to try first. Other engineers point out how they had tried that before and it didn't work; but maybe this other way will. So, they end up "working together" on the refactor instead of one developer getting lost in the sauce for a week seeing what sticks to a wall.
In essence, about the same amount of time is spent; but the code is higher quality and no architecture reviews during code reviews (which is another rule that should exist on a team -- architecture reviews should happen before a single line of code is touched).
In most cases where I see responses like this, they're not surprised to wait hours or days for a PR review. In that case, it makes sense to go big, otherwise you'll never get anything done. If you only have to wait half an hour, max, for a PR review; the extra code churn is 1000% worth it.