Every layer of review makes you 10x slower • Hacker News Board

Re: Every layer of review makes you 10x slower

#21

Post by eru » Tue, Mar 17, 2026, 5:15 AM UTC

josephg wrote: post #20

markbao wrote: post #7

If you save 3 hours building something with agentic engineering and that PR sits in review for the same 30 hours or whatever it would have spent sitting in review if you handwrote it, you’re still saving 3 hours building that thing. So in that extra time, you can now stack more PRs that still have a 30 hour review time and have more overall throughput (good lord, we better get used to doing more code review) This doe…

If your team's bottleneck is code review by senior engineers, adding more low quality PRs to the review backlog will not improve your productivity. It'll just overwhelm and annoy everyone who's gotta read that stuff. Generally if your job is acting as an expensive frontend for senior engineers to interact with claude code, well, speaking as a senior engineer I'd rather just use claude code directly.

Linting, compiler warnings and automated tests have helped a lot with the grunt work of code review in the past.

We can use AI these days to add another layer.

Re: Every layer of review makes you 10x slower

#22

Post by onion2k » Tue, Mar 17, 2026, 5:17 AM UTC

But you can’t just not review things!

Actually you can. If you shift the reviews far to the left, and call them code design sessions instead, and you raise problems on dailys, and you pair programme through the gnarly bits, then 90% of what people think a review should find goes away. The expectation that you'll discover bugs and architecture and design problems doesn't exist if you've already agreed with the team what you're going to build. The remain 10% of things like var naming, whitespace, and patterns can be checked with a linter instead of a person. If you can get the team to that level you can stop doing code reviews.

You also need to build a team that you can trust to write the code you agreed you'd write, but if your reviews are there to check someone has done their job well enough then you have bigger problems.

Re: Every layer of review makes you 10x slower

#23

Post by MeetingsBrowser » Tue, Mar 17, 2026, 5:18 AM UTC

simonw wrote: post #11

This is one of the reasons I'm so interested in sandboxing. A great way to reduce the need for review is to have ways of running code that limit the blast radius if the code is bad. Running code in a sandbox can mean that the worst that can happen is a bad output as opposed to a memory leak, security hole or worse.

Isn’t “bad output” already worst case? Pre-LLMs correct output was table stakes.

You expect your calculator to always give correct answers, your bank to always transfer your money correctly, and so on.

Re: Every layer of review makes you 10x slower

#24

Post by lelanthran » Tue, Mar 17, 2026, 5:29 AM UTC

markbao wrote: post #7

If you save 3 hours building something with agentic engineering and that PR sits in review for the same 30 hours or whatever it would have spent sitting in review if you handwrote it, you’re still saving 3 hours building that thing. So in that extra time, you can now stack more PRs that still have a 30 hour review time and have more overall throughput (good lord, we better get used to doing more code review) This doe…

> So in that extra time, you can now stack more PRs that still have a 30 hour review time and have more overall throughput

Hang on, you think that a queue that drains at a rate of $X/hour can be filled at a rate of 10x$X/hour?

No, it cannot: it doesn't matter how fast you fill a queue if the queue has a constant drain rate, sooner or later you are going to hit the bounds of the queue or the items taken off the queue are too stale to matter.

In this case, filling a queue at a rate of 20 items per hour (every 3 minutes) while it drains at a rate of 1 item every 5 hours means that after a single day, you can expect your last PR to be reviewed in ((8x20) - 1) hours.

IOW, after a single day the time-to-review is 159 hours. Your PRs after the second day is going to take +300 hours.

Re: Every layer of review makes you 10x slower

#25

Post by loire280 » Tue, Mar 17, 2026, 5:32 AM UTC

onion2k wrote: post #22

But you can’t just not review things! Actually you can. If you shift the reviews far to the left, and call them code design sessions instead, and you raise problems on dailys, and you pair programme through the gnarly bits, then 90% of what people think a review should find goes away. The expectation that you'll discover bugs and architecture and design problems doesn't exist if you've already agreed with the team wh…

I've seen engineers I respect abandon this way of working as a team for the productivity promise of conjuring PRs with a coding agent. It blows away years of trust so quickly when you realize they stopped reviewing their own output.

Re: Every layer of review makes you 10x slower

#26

Post by JoshTriplett » Tue, Mar 17, 2026, 5:34 AM UTC

lmm wrote: post #14

sublinear wrote: post #9

As they say: an hour of planning saves ten hours of doing. You don't need so much code or maintenance work if you get better requirements upfront. I'd much rather implement things at the last minute knowing what I'm doing than cave in to the usual incompetent middle manager demands of "starting now to show progress". There's your actual problem.

> As they say: an hour of planning saves ten hours of doing. In software it's the opposite, in my experience. > You don't need so much code or maintenance work if you get better requirements upfront. Sure, and if you could wave a magic wand and get rid of all your bugs that would cut down on maintenance work too. But in the real world, with the requirements we get, what do we do?

> In software it's the opposite, in my experience.

That's been my experience as well: ten hours of doing will definitely save you an hour of planning.

If you aren't getting requirements from elsewhere, at least document the set of requirements you think you're working towards, and post them for review. You sometimes get new useful requirements very fast if you post "wrong" ones.

Re: Every layer of review makes you 10x slower

#27

Post by jauntywundrkind » Tue, Mar 17, 2026, 5:46 AM UTC

onion2k wrote: post #22

But you can’t just not review things! Actually you can. If you shift the reviews far to the left, and call them code design sessions instead, and you raise problems on dailys, and you pair programme through the gnarly bits, then 90% of what people think a review should find goes away. The expectation that you'll discover bugs and architecture and design problems doesn't exist if you've already agreed with the team wh…

I wonder what delayed continuous release would be like. Trust folks to merge semi-responsibly, but have a two week delay before actually shipping to give yourself some time to find and fix issues.

Perhaps kind of a pain to inject fixes in, have to rebase the outstanding work. But I kind of like this idea of the org having responsibility to do what review it wants, without making every person have to coral all the cats to get all the check marks. Make it the org's challenge instead.

Re: Every layer of review makes you 10x slower

#28

Post by onion2k » Tue, Mar 17, 2026, 5:48 AM UTC

loire280 wrote: post #25

onion2k wrote: post #22

But you can’t just not review things! Actually you can. If you shift the reviews far to the left, and call them code design sessions instead, and you raise problems on dailys, and you pair programme through the gnarly bits, then 90% of what people think a review should find goes away. The expectation that you'll discover bugs and architecture and design problems doesn't exist if you've already agreed with the team wh…

I've seen engineers I respect abandon this way of working as a team for the productivity promise of conjuring PRs with a coding agent. It blows away years of trust so quickly when you realize they stopped reviewing their own output.

Putting too much trust in an agent is definitely a problem, but I have to admit I've written about a dozen little apps in the past year without bothering to look at the code and they've all worked really well. They're all just toys and utilities I've needed and I've not put them into a production system, but I would if I had to.

Agents are getting really good, and if you're used to planning and designing up front you can get a ton of value from them. The main problem with them that I see today is people having that level of trust without giving the agent the context necessary to do a good job. Accepting a zero-shotted service to do something important into your production codebase is still a step too far, but it's an increasingly small step.

Re: Every layer of review makes you 10x slower

#29

Post by zmmmmm » Tue, Mar 17, 2026, 5:53 AM UTC

lelanthran wrote: post #24

markbao wrote: post #7

If you save 3 hours building something with agentic engineering and that PR sits in review for the same 30 hours or whatever it would have spent sitting in review if you handwrote it, you’re still saving 3 hours building that thing. So in that extra time, you can now stack more PRs that still have a 30 hour review time and have more overall throughput (good lord, we better get used to doing more code review) This doe…

> So in that extra time, you can now stack more PRs that still have a 30 hour review time and have more overall throughput Hang on, you think that a queue that drains at a rate of $X/hour can be filled at a rate of 10x$X/hour? No, it cannot: it doesn't matter how fast you fill a queue if the queue has a constant drain rate, sooner or later you are going to hit the bounds of the queue or the items taken off the queue…

This is the fundamental issue currently in my situation with AI code generation.

There are some strategies that help: a lot of the AI directives need to go towards making the code actually easy to review. A lot of it it sits around clarity, granularity (code should be committed primarily in reviewable chunks - units of work that make sense for review) rather than whatever you would have done previously when code production was the bottleneck. Similarly, AI use needs to be weighted not just more towards tests, but towards tests that concretely and clearly answer questions that come up in review (what happens on this boundary condition? or if that variable is null? etc). Finally, changes need to be stratified along lines of risk rather than code modularity or other dimensions. That is, if a change is evidently risk free (in the sense of, "even if this IS broken it doesn't matter) it should be able to be rapidly approved / merged. Only things where it actually matters if it wrong should be blocked.

I have a feeling there are whole areas of software engineering where best practices are just operating on inertia and need to be reformulated now that the underlying cost dynamics have fundamentally shifted.

Re: Every layer of review makes you 10x slower

#30

Post by zmmmmm » Tue, Mar 17, 2026, 5:55 AM UTC

CuriouslyC wrote: post #19

markbao wrote: post #7

If you save 3 hours building something with agentic engineering and that PR sits in review for the same 30 hours or whatever it would have spent sitting in review if you handwrote it, you’re still saving 3 hours building that thing. So in that extra time, you can now stack more PRs that still have a 30 hour review time and have more overall throughput (good lord, we better get used to doing more code review) This doe…

Except that when you have 10 PRs out, it takes longer for people to get to them, so you end up backlogged.

And when the PR you never even read because the AI wrote it gets bounced back you with an obscure question 13 days later ..... you're not going to be well positioned to respond to that.