[331c8c71]

> At the one company I was where we did code reviews, they took at most one hour per day. > They definitely didn't take 50% of our time.

Imo introducing code reviews might very well decrease the velocity by 50% even if the actual time spent on code reviews is much less.

I see at least two reasons for this: 1) increased need for synchronization/communication 2) increased subjective frictions and mental overhead (if only for task switching).

Code reviews are not special in this respect, similar effects can be caused by any changes to the process.

[strogonoff]

Thorough code reviews are expensive. When I review code, I have to know how to solve the problem well in the first place—that is, do all of the effort that went into writing the original code under review, minus time spent typing.

Less time may be required if you have good rapport and long work relationship with the person, but I would say halving productivity sounds about right if we are talking mandatory reviews.

Using an LLM to generate code means having to do the same. The longer the autocompleted text, the more careful you have to be vetting it. Lower predictability, compared to a person and especially one you know well, means that time requirement would not go down too much.

[deergomoo]

> When I review code, I have to know how to solve the problem well in the first place—that is, do all of the effort that went into writing the original code under review, minus time spent typing

Agree 100%, even when LLMs aren’t involved.

Certainly not all code reviews are like this—in many cases the approach is fundamentally sound, but you might have some suggestions to improve clarity or performance.

But where I work it’s not all that rare to open up a PR and find that the person has gone full speed in the wrong direction. In those cases you’re losing at least a morning to do a lot of the same leg work they did to find a solution for the problem, to then get them set off again down a better path.

Now in the ideal case they understood the problem they needed to solve and perhaps just didn’t have the knowledge or experience to know why their initial solution wasn’t good; in such a scenario the second attempt is usually much quicker and much higher quality. But introduce LLMs into the mix and you can make no guarantees about what, if anything, was understood. That’s where things really start to go off the rails imo.

[strogonoff]

> in many cases the approach is fundamentally sound

Sure, but I mean you still have to determine whether it is sound or not in the first place; i.e., you must know how to solve the problem. You can only evaluate it as right or not if you have something to compare against, after all.

If you have worked with a person for a while, though, I can see that you can spot various patterns (and ultimately whether the approach is sane) faster thanks to established rapport. Not so with LLMs, as you probably agree.

[PoignardAzur]

I mean, it's something we did once per day, usually towards the end of the day. This was pre-Covid, so our manager was in the room next to ours and we could just pop by his office to tell him we were ready for today's review.

It really doesn't need to be a massive amount of task-switching. And the benefits were obvious.