Thing is, I've lead my fair share of teams and I trust my team-mates and colleagues implicitly. It makes for a strong team. But we still do code review (peer review) because we want to build software that works well and support each other. We're not in the job to simply deploy code to prod as quickly as possible.
I'd also add that I think any software engineer should try and have the experience of working in a highly regulated field, like healthcare. It's hard to get an appreciation for why these things exist until you realise you're held to a much higher level of accountability because your oopsie moments can have much larger consequences. For me, it's been hard to go back to my old, cavalier attitude after that.
TFA:
> Engineers [..] request reviews when they think it's necessary.
Problemo solved.
It does however mean you don't sit around waiting for someone to approve a three line delete PR that you know is safe. The "Rubber Stamp" review is a thing and it does waste time.
I'd be exactly in the boat you describe (and actually: I've yet to see a situation where someone reviewing my code did not lead to improvements). But: If I want my code reviewed, I have to actually fight for it. Since everybody's workload is too high, even the willing often simply don't have the time.
From higher up, at our place, there's no one that actively opposes code review as a practice, but they don't seem to get that it requires investment (i.e. time), either. That means that if management refuses to change their ways of planning or explicitly enshrine reviews as priority tasks, it simply won't happen except for maybe the gnarliest cases.
And that's from a perspective of the change's author being willing and proactive. I work with individuals that produce very questionable code at times. And I'm not talking style here: Code in 2021 that still is prone to SQL injection at every turn. Methods that are hundreds of lines long with a gigantic cyclomatic complexity that no one (including the author) will ever really understand. Method names like "process" and "process2". And so on.
Needless to say, those programmers will never push for their changes to be reviewed. The rest of the team simply discovers them after they blow up (which they do regularly) and we're debugging.
Now, these people are luckily a tiny minority (which at least makes this somewhat bearable), but I over and over again would wish for someone with more authority to show that they're interested in the matter. Which a policy on code review would do -- if only as a signal. Yes, we want to check each other's code. Yes, we want collaboration. Yes, that's more important than some arbitrary deadline for minor feature X. Yes, we expect our programmers to be professionals.
Another symptom of such an environment also is the fact that everyone is the king of their particular hill. No one every familiarizes themselves with another person's code unless they really have to. By now, I've jumped to insisting that every change on a critical component I'll ever make will be done through pair programming, and so far, at least that seemed to stick. But again -- that only happens if both parties involved actively fight for it instead of everybody understanding that this is just an expected part of work.
Was interesting to hear your experiences and maybe update my expectations of workplaces somewhat
> [...] alongside the culture of my employer [...]
I think you've hit the nail on the head here. As many others have said in different HN posts, culture is hard to change. And I would also understand the argument that one can also enforce culture changes with policies; my hope up to now simply has always been that engineers could "overrule" some artificial time limits in favor of more collaboration by referencing such a policy.
I guess if you're starting from a context where code reviewing practices "just work", introducing explicit policies also can't improve much, anyway. On that note: If you happen to know a good heuristic to detect such cultures during interviews or the like, I would be extremely interested :)
This hits at the heart of why I strongly agree with this post and think PRs and code reviews are ultimately destructive.
Reviews are going to get dropped _regardless_ of whether they are in the process or not. Pressure makes code reviews and quality worse, not better.
More than that, the need to "appear" to review is going to slow things down and can cause an exponential back up. I saw this happen about a mouth ago: 3 day release cycle got bogged down and then took _3 weeks_ to get a single release out.
Process goes out the window when pressure hits. You are then operating in foreign environment at the most critical point and your safety net of useless.
Your safety net when things need to go fast should be highly automated fast build and deploy, coupled with great test coverage, from unit to end to end.
The only exception might be if you work in highly regulated field where you legal required to have a very low Mean Time To Failure. In that case things move slow unless you are very well resources.
Otherwise (ie the majority of products) focus that effort on having a very low Mean Time to Resolve. If you absolutely need some form of quality assurance, Pair. Do continuous PRs and knowledge sharing rather than out of context after the fact reviews.
There is an easy way to resolve this:
Request peer review for SMALLER chunks of code.
Each small change on its own might make sense and be ok to a reviewer, but if you step back and look at the series of changes together there might be some issues that could have been noticed.
Then that's what you need to fix.
...when they need it. Actually, really good engineers will ask to pair when they need it. Review is a distant second.
I agree with you there, but I'm also sure that one reason for this is that many people still see reviews as the task that only happens after everything else.
I'm convinced there's a lot of useful middle ground to be had if reviews aren't just "here's 500 LOC, please review", but maybe more… staged.
Say: Rummage around in the code a bit for yourself (ask questions if you have to), come up with a strategy of solving your problem, and submit that for review. Not in code, but maybe using markdown, preudocode, small diagrams or the like. In person (i.e. via screenshare nowadays). And if the other party doesn't find obvious holes in your strategy, then go implementing it.
I remember an interview with some Linux kernel maintainer that mentioned the same effect -- people submitting a gigantic patch for something that will simply never be merged. And all that would have been necessary to avoid this wasted work was an e-mail asking if the maintainers are at all interested in the change.
One downside of code review is reduced velocity. There are teams out there who use code review so effectively that they never ship big fuck-ups to production. They never have to tell clients that they have bad practices. Instead, they struggle to get clients because they pay much more per line of code shipped and therefore don't deliver as good of a value as their competitors.
This where the argument needs to be: whether and how to have code reviews be a net positive.
I can see how that equation balances in favour of no code review when it's in the context of a startup that is probably still figuring out how to make money, especially with a subscription based app launcher. As far as prototyping and early stage iterations go, you're probably just seeing what works and reviewing the code isn't so important at that point. There would still be one or two things you'd ask someone to check, e.g. security related stuff.
I think you make a good point though: what makes an effective code review process? I don't think there's a single answer to that because it depends on the circumstances.
I would at least say that it goes better if it's treated as a priority and issues are raised and dealt with promptly, rather than leaving it as a chore you eventually get around to. And you would have to see value in it beyond it being a sanity check, as others in this thread have described (knowledge transfer, for example).
We really should be relying on automated systems to catch bugs for the most part, and leave code review for what it's good for: making sure a different human can understand and maintain the code.
In fact, if we manage to catch a bug in a code review that didn't also trigger our automated systems to alert us, that should probably prompt us to look into how we can expand the coverage of that automated system, similar to what we'd do in a postmortem if the bug wasn't caught in code review and reached production, because we can't rely on that happening the next time.
Disagree, but it's also a good place to be ensuring that the system is evolving in a way that is reasonable and consistent — or that it is unreasonable and inconsistent for good reasons.
I’ve always code reviewed/gotten code reviewed on both the implementation and the tests, with completeness as the main quality you’re reviewing test code for. If that’s how we do it, we’re right back at code reviews.
I'm not saying code review can't find any bugs (in practice bugs are found in code review all the time), I'm just saying that if we do find a bug through code review, it means we got lucky, and we shouldn't count on getting lucky again, so better add a test/linter rule for the next time when we might not get so lucky. That's just one more way to grow your automated systems organically.
What big launch? :) Is useful to feature flag new functionality so that you can release gradually and spot the bugs - often via error monitoring and user feedback - before they affect everyone. Yes, realize it can happen but there are techniques to minimize the chance of it happening.
However, the review process is far from perfect and can create a false sense of security.
To review a piece of code, that code should ideally be small in scope. For larger pieces it's rather common that the reviewer don't have enough time to do a good job.
If there were better incentives for doing a review, then it would greatly improve the situation.
But i haven't seen that yet.
In almost all cases it's very hard to get people to look outside the web browser for the diffs. Diffs show you something, but never the whole context.
The other problem I've found is stamping down on style arguments: they have no place in code reviews, and a lot of the time you get a round of "please change this variable to be named something else" - which might be valid, but raises the question of why the reviewer didn't do it, and more often leaves a weird authority gap - I have no power to just reject such a request because I think it's invalid, nor does the business have anyway to resolve the issue. In fact if there's a dispute at all, very rarely is there any process for bringing in a third party to mediate or break the stalemate (which is hilarious in some ways since everyone by now should realize 2-party systems can't achieve consensus).
Code reviews are very, very cargo-culty and I've not seen them ever include a thorough design: people give up on the very near edge cases, and so the whole system falls apart because it's just a hurdle to get through and not a collaborative or constructive process.
Or are you saying that one can actually find more bugs when two people compile and execute the same code rather than just one?
When I review code, I want the author to tell me how they have verified that the code has the desired effect -- but if they do that, I'm going to trust that they did the actual verification and I'm not going to simply retrace their steps. That seems like a waste of time to me.
1) Catch edge use case / business requirements misunderstandings
2) Mentor new hires/junior engineers on the ways things should be done (e.g. internal culture about some architecture/design).
BUT, I absolutely despise code reviews that nitpick on non documented or 'because I prefer that way' stuff:
1) Task tickets that only have a vague description, have their own 'play detective' about the requirements, but a lot of new ones surface during code review.
2) Requirements are met, but there are internal/personal technical directives that are written nowhere, are not enforced with automated checks and may dramatically change a feature/patch is implemented (I can only think about that guy that worked in a company in which only LEFT JOIN sql statements were allowed).
Fuck that noise.
The main purpose of code reviews is checking the general structure of the code and tests. Is the code well designed? Are error cases considered and tested? Another important purpose of code reviews is knowledge sharing.
To spot quality problems before going to production .. what you need is testing.
Not "unit testing" - which is just another pointless process that does not actually provide the purported benefits.
You need a separate QA team that handles testing - manual and automated.
You should absolutely have a small QA team, but their job shouldn't be doing the QA -- it should be helping others do their own QA.
One thing I've seen that I like a lot is individual changes creating individual front ends. You test the one thing in that change, and it's done. This tends to cause a lot of problems with CORS, but then what doesn't?
Agreed with you though that good code reviews (whatever that means) obviates most of this.
Your quality problems might well come from poor or non-existent architectural decisions and tech-debt, and QA won't pick up on that stuff unless it manifests as a faulty requirement.
The earlier you catch a problem, the easier it is to fix.
In our case we have a public API and several backends. The tests run against the public API. To know that a new backend is working it has to pass all the tests. Getting any new backend working correctly without the tests would be nearly impossible.
I’ve heard from my workplace’s software team that this makes hiring from certain sectors particularly difficult because they don’t get this. Too used to move fast and break things and MVP.
On my team, the majority of code review comments are not discussing potential bugs, they're making sure everybody knows how the new thing works, why it was designed that way, implementation tradeoffs, etc. All that discussion is extremely valuable over the long run. For example, it means that nobody has to pay attention to email while they're on vacation in case something goes pear-shaped with a module they implemented.
That said, I 100% agree with the article's concluding paragraph about YMMV. Raycast is operating in an entirely different business domain from the one I'm in. It sounds like the reasons why Raycast likes their way of doing things don't really apply to us, and I don't think the reasons why we like our way of doing things don't really apply to Raycast.
I like a hybrid "the person who wrote it can't deploy it" model. You get an informal code review and two sets of eyes/brains to the extent that the deploying engineer feels like they understand it enough to shepherd it into prod weighted against how important the component and the scope of the change is.
It self scales from "copy change on the website yolo" to "this involves two new racks of servers and a database migration, I'm going to need to spend a week understanding it to the point I can make a plan."
This is the most common reason I see cited for code reviews, but I'm not entirely sure if I buy it, at least not for a lot of teams.
In most cases you are going to have one, maybe two other people looking at a given PR. The positive way of looking at this is that you've just doubled (in some cases tripled) the number of people who are familiar with the code. In reality though, this is still going to be a very small fraction of most engineering organizations. If you have a small team who wholly owns a small codebase then it could be meaningful, but a lot of the time you're still talking about a rounding error from zero people knowing the code- most people in the organization will still be touching the code in the future without any prior knowledge of it, and will have to start understanding it from zero.
Even if you are dealing with a small enough code base, in a small enough team, that the reviewer is adding a substantial margin of familiarity with the codebase to the team, reviewing the code is only going to give an extremely shallow level of understanding. The reviewer isn't going to have all of the context that the original developer had. They won't know all of the things that weren't done or why, the tradeoffs that were made, requirements, business context, etc. Best case scenario, someone wrote that down in a well-known place (comments in the code near the feature, something relevant in a docs directory, hopefully not as an archived jira issue that will never be looked at again). The reviewer probably has their own work to do anyway, and once they approve the PR they'll flush most of what they had out of their short-term memory anyway.
In a lot of ways, this is the same set of reasons that people aren't very likely to find bugs in a code review either. Someone without a lot of context on the problem isn't likely to find many business logic errors, or missed requirements. Since you were busy working on your feature, you probably don't know who else on what other teams might have been doing something relevant to your work, so you wouldn't know to get a review from people who might have something useful to contribute (and they wouldn't know to proactively review your code). One of the reason senior engineering roles often devolve into telling people to talk to one another is to try to address this kind of situation, but that only scales up to a small fraction of the overall code churn at organizations of any size.
For what it's worth, I ask for PRs, and I review my co-workers code. I make comment when I see something that might be useful, and I graciously accept feedback and try to make sensible decisions about when to make changes and when to let the feedback go. I actively search for PRs that might touch sections of the code I've been working in or am very familiar with to try to optimize the quality of the feedback I can give. I'm not really convinced any of this actually helps deliver better code in the moment, but maybe it does some good as a way to help teach my co-workers about things (or to learn about things they can teach me), and anyway it's such an ingrained part of engineering culture that it doesn't seem worth the political capital you'd have to spend to try to change it, and even if you succeeded it would be a prime target for scapegoating if anything went wrong later. It does slow down the development process I think, but people need down time anyway. If waiting on a code review gets people an hour or two of downtime to check their email or read HN between tasks then maybe it's actually worth it for that. The burnout caused by superfluous process and the occasionally large pile-ons and people demanding poorly thought out changes, gatekeeping your ability to deliver business critical work is essentially a cost of doing business that we seem to have collectively accepted in software.
I should also note that I also work on some open source projects, and in that setting PRs work much better. Not only does such code often need more review, but you also typically have a smaller group of people who know the whole codebase, and are much better central repositories of knowledge. The review process is also a much more effective way of doing collaborative decision making in an open source project IMHO.
That said, I do sometimes encounter individuals or cultures that seem to view code review more as a mechanism for catching abnormal/unexpected mistakes than as a normal part of the process of writing code.
It's precisely because I've learned to read and write so fast that I "skip over" the simple parts of sentences, making me oddly blind to certain categories of spelling errors!
Especially when I've gone over the same text over and over, I'll have memorised it to the point that I can skip entire sentences.
This is why you need someone else to step in and read the text for the "first time" and not skip anything.
The same applies to programmers and code review.
No it's not.
If an author produces gibberish and nobody checks, the published result is gibberish. And with print books uneditable in a run starting in the thousands.
If a programmer produces gibberish, it won't compile.
It also won't pass the unit test or acceptance tests, never mind QA or the alpha/beta testers.
But I think it's still the right analogy. You code review to make sure the code is comprehensible to other humans. You code review to make sure the tests (which are great automated protections) are protecting against the right things. And (most relevant to the analogy) getting those things wrong are not abnormalities that mean you're a bad programmer and we don't trust you, they're things that competent devs can get wrong all the time.
The equivalent in book writing would be that you are not allowed to write more than one page at a time, and someone must approve it before you start working on the next page.
If books were read by machines rather than humans, and were published incrementally, then it would make sense to ask someone to edit each iteration.
Incorrect. Bugs (“errata”) are regularly fixed in bugfix versions (“printings”) of books, whereas feature changes are regularly fixed in more major versions (“editions”). And that’s after the equivalent of a “1.0” release.
Books are also regularly iteratively released either to a closed group of reviewers or even the public (e.g., Manning MEAPs, PragProg Beta Books, etc.) prior to the equivalent of a “1.0” release.
But those fixes don't fix the already printed books.
For actual physical books (as opposed to ebooks, where making the complete new version available to purchasers for errata, but usually not new editions, is common), this is usually true for logistical reasons, though issuing errata sheets (usually online now, though the practice is older but notification and distribution was harder in the past) to keep existing users up-to-date is not uncommon.
Only for a drive-by take-down by someone with none of the context. It's a totally asymmetric investment of time. Even helpful review comments might only take a minute to write but a day to incorporate.
If that's a regular issue that's a culture problem. Starting with "if you've been talking with colleagues about your problem, why is someone with no context reviewing the result?", people not investing time in reviews, people doing "take-downs" instead of asking questions if they don't understand things, hold up merge for non-urgent concerns ...
> Even helpful review comments might only take a minute to write but a day to incorporate.
Either the feedback is worth the investment of the day of time, then no problem, otherwise it's not that important and doesn't need to be done (or depending on what it is can be done later or ...)
Couldn’t one also argue that if code reviews are routinely catching problems mentioned earlier in the thread (misinterpreted requirements, conflicts with other WIP, etc.) then that’s a cultural problem? It just seems odd to assume that the person assigned the task couldn’t possibly be expected to routinely avoid those problems, but that adding rigorous code review could routinely avoid them.
Except that this decision is often not up to the code author, because the tooling rejects for example committing changes until all discussions are resolved (see Gitlab for example) and some @holes make their quest for any reason not to resolve the discussions that they started until the code author writes the exact code with the exact words in the exact indentation with the exact architecture, etc that those @holes like, which makes the whole code review like a torture and the REAL productivity killer. Not to mention that this does not provide any improvement to the code base either in most cases.
If this is an issue in your workday, you should bring it up with management or the individual rejecter. If someone has the authority to kill PRs, they should also be required to put in the effort to understand it and/or be available for discussion at an earlier stage of the development process. PRs shouldn't ever be rejected without mutual agreement - neither internally in an organization, or in an open source project.
Then write it down. If the code reviewer can't follow what's going on, what hope is there for the new hire looking at it six months from now?
It'll be 6-months if you're lucky. Try figuring out why there's a particular "if" clause, one or two or four years later. Software maintenance, especially when the original author has moved onto another team/organization/company/career, is a frustrating art of almost remembered stories and hoping that you can figure out Chesterton's fence, lest it become Chesterton's barbed wire. The worst is when you fix a small bug with code and introduce an even bigger big in the process.
Code reviews aren't a "take-down", they're a process of helping each other produce better solutions and better code.
> Even helpful review comments might only take a minute to write but a day to incorporate.
Then like all pieces of work, a decision must be taken whether that day is worth it, no?
[0] Not just because the reviewer is trying to be nice, but because they don't know what constraints and problems the author discovered in the process of writing the PR. If the reviewer writes "use a map here, instead of scanning an array" without knowing how many items are handled, then they may be making the PR worse by replacing a cheap linear scan over a maximum of 50 items with a bunch of costly yet constant time hashing. Often the solution is an explanatory comment rather than the "obvious" fix.
Good reviews can take a light touch, in part by differentiating non-blocking ideas and suggestions from "hey I think this is a bug."
Some of my favorite reviews of all time actually don't change a single line of code, but the questions reviews ask zero in on what's going to confuse the next developer so it can be documented appropriately.
I don't see any other reason to require code reviews before a change can be merged.
> humans make mistakes
Then write unit tests, religiously. And pair. Or "... request reviews when they think it's necessary".
In my experience code reviews are not very good at catching mistakes.
> Different work in progress can be in conflict with each other.
Code reviews are the cause of too much work in progress, not the solution. Not the only cause.
> Reviews are a good way to learn from each other
In my experience, they are pretty bad at this. Pairing is vastly superior, or giving talks.
> reason to communicate with devs I might not otherwise communicate with
Then communicate with them. And if you want a review "... request reviews when they think it's necessary".
> Rejected
Exactly. That's not a useful form of interacting with your peers.
In the US, a SOC 2 audit of your org’s change management process is going to be a really bad time without this.
The deciding factor was ownership and accountability tho - you maintained own code and if you done it crappily, you knew.
The code review is related to assumption that everyone can change everything - meaning all in all inconsistent mess. It is also related to unfortunate assumption that code review is how people learn system. They don't, unless they are original author. The rest of then knows pieces of it only.
Ownership and accountability are workable as long as the same person sticks around long enough to fix all their mistakes. If that person leaves, the code becomes orphaned and it's up to one of their teammates to find out where the skeletons are buried.
And the person doing explanation actually understand the whole part. That is big one too - you are not explained bits of it by someone who knows only small parts of it. And the system was not changed by third party without the person who explains having at least vague idea it was changed.
> Ownership and accountability are workable as long as the same person sticks around long enough to fix all their mistakes. If that person leaves, the code becomes orphaned and it's up to one of their teammates to find out where the skeletons are buried.
That is actually exactly the same without clear areas. Except everyone is new all the time.
If you have high turnover, this aspect will be bad matter what.
And it is not that bad with responsibility either. Old person does explains things to new person. Taking over, when you are working consistently in same area is not that hard, actually. Some parts you conclude to be mess, but usually not whole of it.
---------
And imo, quality and knowledge heavily depends on other parts of team. Analysis and testing. Both, if work reasonably well are massive resource for knowing how the hell the system is supposed to work.
And once you have reliable source for requirements, that is not developers, then deciphering the code is much easier.
As a result, any work that's assigned to someone else will only interact with at the interfaces / boundaries. And of course, that's sort of the intention with modularity / loose coupling - it's not necessary to learn the gory details of the XYZ subsystem's implementation, only its API. Knowing the details is certainly valuable, but there's no baseline impetus to get the owner to explain the details.
Taking over from someone who's ceding responsibility, but staying at the company, I agree that's manageable. But sometimes people get laid off suddenly (or perhaps get hit by a bus, etc) and there's no chance to get the one person who has it all in their head to explain it to you.
You mentioned high turnover, but if anything, a place with high turnover has less information locked up in a single person's head. If Alice who's worked at the company for 25 years and has always owned the code leaves, you're going to have a much harder time getting all of the tribal knowledge out of her head on two weeks notice compared to Bob who only made it 6 months.
To me, the value of code review is that even at its worst, someone other than the author is forced to look at the code. No process can force a reviewer to take an active interest in a particular subsystem, but at least we can make them look at pieces of it and see if it gets them curious enough to ask further questions of the author and better understand the system.
For myself, knowing that someone else will have to understand my code, even through the limited lens of a code review, makes me more diligent about making sure that the code is clean and the pull request has enough context that someone playing code archeologist will be able to make sense of it, even if I'm not walking them through it in real time. I will admit that this is not a universal thing - I've worked with coworkers where no matter what process is in place, they won't do the basic courtesy of reading their own changelists to see that they accidentally committed random junk files from their local machine.
I agree that good documentation around requirements is valuable. I find pull requests / code reviews are a great opportunity to highlight how the code relates to specific requirements, since the focus is narrower.
Informal reviews can have a lot of different shapes, and provide a lot of different benefits. But anything that is a stop-the-process activity is there because you expect quality problems from the earlier steps.
(That said, no good developer trusts oneself. So if you don't have anything on your process that makes you trustworthy, lack of trust is the correct approach.)
I'm a fan of code review
For me, code review is collaboration. We're helping each other.
The one thing I'd suggest is, as much as possible, try to phrase reviews like a question: "Do you mean to do X here?", "Would using fooTheFob here work?", "Is this a race condition?". At least it feels better to me.
Is the phrase "trust but verify" an attempt to avoid damaging self-esteem? There seems to be some emotional/ego-based attachment to the concept of trust.
I never work directly on master, always on a branch, and when I'm done I create a PR for myself.
Can't remember a single PR that I reviewed where I didn't find some issue or bug.
I guess you can say I don't trust myself...
> Pull requests don't prevent bugs. Reviewing code is hard! You can catch obvious mistakes, but you won't have consistent in-depth scrutiny. Many issues reveal themselves only after extensive use, which doesn't happen during code reviews. We rely on fast iterations with user feedback.
So many things I can say about this. "Fast iterations with user feedback" are great, until you introduce a security bug that you find out about because someone exploits it. Catching "obvious" mistakes alone has significant value. Since he acknowledges that code reviews catch some bugs, this criticism seems to be that they don't catch all bugs. To that, I say: show me a practice which does catch all bugs, and I'll show you why it doesn't. Even the most rigorous development process doesn't prevent all bugs. [0] This just doesn't sound like a fair criticism to me.
> Pull requests slow down. Code reviews aren't high priority for engineers. They have to make time to clean up their review queue. In reality, PRs are an afterthought and not what you want to spend your time on as an engineer.
This is largely a culture problem. Code review should be a high priority for engineers. Maybe it's not the highest priority, but, it's fair to expect one could get a decent review on a PR that isn't too large in, say, 1-2 days or less. If you have PRs sitting in review for weeks at a time on a regular basis[1], one of two things is happening: either engineers aren't properly prioritizing code review, or your PRs are too large and/or have too many dependencies.
Which brings me to the second thing you can do, which is make PRs that are as small and simple as possible, but no more. Minimize dependencies to help make your PRs understandable. And, it should be fairly obvious, but the fewer lines of code (including config changes) you have in your PR, the easier it will be to review, so, the faster it will get done.
Code review is also a great opportunity to learn and teach. Every senior+ engineer should be reviewing code frequently, IMO.
Finally, yes, code reviews will slow you down if your basis for comparison is just "engineers merge code when they think it's ready." That's intentional, and good. The cost is more than paid for by better code quality, leading to fewer instances of "here's a PR to fix the issues with my previous PR."
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[0]: https://news.ycombinator.com/item?id=29801451
[1]: I've only had this happen once or twice in my career so far. In each case, it was because the code surrounding the code I was working on was not stable and kept changing. These were clearly exceptional instances.
Is that why we do code reviews, because we don't trust each other? I find this attitude problematic. We do code reviews because humans make mistakes. Requirements can be misinterpreted. Different work in progress can be in conflict with each other. Reviews are a good way to learn from each other and keep abreast of what work is occurring outside your own bubble. Not doing code reviews because of "trust" kind of misses the point.
I find even just cursory and brief code reviews are beneficial and often pick up on issues. It also creates a more collaborative team and gives me a reason to communicate with devs I might not otherwise communicate with, even if that is just a brief comment on a PR.
Rejected.