Dan Luu
@danluu
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Active on https://t.co/WG71NrsDQk; also trying out https://t.co/DBk2OnBVL1. No longer read replies or notifications here now that tweetdeck is gated.
Joined December 2008
"Unfortunately, a recent software update was not successful. Your vehicle cannot be driven. Please call customer support:"
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Every once in a while, I think about going to work in the game industry.
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A former Apple engineer discusses Google product culture:. > My director wore an Apple Watch and had an iPhone . my VP too. Nobody was expected to eat the dog food and so few did. This was crazy to me coming from Apple .
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Current and former Google engineers discuss how Google has changed:
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Long-time Microsoft employees explain changes in Windows: . Designers were handed full control over UX. Engineers who fought for usability over a slick-looking interface burned out and left after repeatedly being overruled.
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"Hardcore" engineering at Twitter 2.0: "To address extreme level of data scraping & system manipulation", Twitter added rate limiting on the backend which seems to have created a retry storm from the client that DDoS'd Twitter for at least eight hours.
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State of the art anti-cheat techniques:. Roblox detects if you have the string "x86dbg" in a window title (or window?), so kids are changing their display names and discord server names to x86dbg to get people kicked from Roblox.
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When it's easier to put up physical a sign than it is to get Google to stop routing people down the wrong road.
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I've find U.S. immigration policy baffling. Back when I was in college, the majority of the top EE students at my university where from China, Korea, or India. Almost all of them wanted to stay in the U.S., but most couldn't, so they went home and worked as engineers at home.
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One thing it took me quite a while to understand is how few bits of information it's possible to reliably convey to a large number of people. When I was at MS, I remember initially being surprised at how unnuanced their communication was, but it really makes sense in hindsight.
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One of the things that I think is sad about the decimation of Twitter eng is that Twitter was doing a lot of interesting (and high ROI) engineering work that, at younger companies, is mostly outsourced to "the cloud" or open source projects. A few examples off the top of my head:.
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My favorite conspiracy theory:. Cryptocurrencies are an effort by time travellers to forestall the AI apocalypse via computational terrorism, making compute, storage, etc., too expensive for superhuman AIs to exist. Satoshi's identity is secret to prevent untimely termination.
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It's astounding how bad the web is without an ad blocker. This tax on using the web, which funds most of it, pays most of the highest paid programmers ($750k/yr+), etc., doesn't impact programmers, who almost all use ad blockers. The whole situation reminds me of the lottery tax.
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An empirical study on the effect of open offices: "the volume of face-to-face interactions decreased significantly (approx. 70%)".
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Amazing analysis by a Columbia professor, showing that Columbia has climbed the USNWR college rankings by submitting fraudulent numbers for. * class size.* % faculty with PhDs.* student : faculty ratio.* instructional spend.* retention & graduation rates.
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An optimized FizzBuzz implementation, for the next time someone asks you to write FizzBuzz in an interview:.
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I got promoted a while back, which really hammered home how arbitrary promos are. I was promoted 2x in 3 years at my current job (senior -> staff -> sr. staff) vs 0x in 3 years at other BigCos. AFAICT, the main difference was that my manager made sure I got credit for my work.
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Workarounds people use to overcome "technical" limitations intended to prevent name changes:.
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I'd been wondering why I see so many people who haven't done anything particularly interesting with "Forbes 30 under 30" on their bio and it turns out there's Forbes has 41 "30 under 30" lists per year, so it's actually "1230 under 30 each year".
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Really nice answer to the question "in layman's terms, what exactly does it mean to be transcendental? How would a transcendental number be different from an ordinary number, say 5":.
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I feel like it would be useful for programmers, as a field, to acknowledge that humans are bad at programming. This is because techniques for improving at things you're bad at are different from techniques for improving at things you're good at.
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I feel like, if you care about learning, long tenures are highly underrated. In online discourse, a lot of people recommend job hopping frequently specifically to learn a lot and avoid stagnation, but I think that's generally the opposite of correct.
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I find this letter from Carmack interesting in that it summarizes a sentiment I've heard from literally all of the highest impact/most effective people I've talked to at large companies:. You can make a big difference, but you're constantly fighting a self-sabotaging organization
I resigned from Meta, and my internal post got leaked to the press, resulting in some fragmented quotes. Here is the full thing:
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Timeline of George R.R. Martin statements on the release date of the next Song of Ice and Fire book:
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This comment describing how Microsoft responded to a security disclosure in 2010 is incredible:.
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This comment, by a real wizard of a programmer, on how their cognitive capability was so reduced in the wake of a viral infection that following the instructions on a box of instant mashed potatoes was too complicated for them, is one of the scariest things I've ever read.
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With the exception of my current team, on every team I've been on since git became popular, I've been "the git person". You know, the person that people WHO ARE PROFESSIONAL PROGRAMMERS go to when their git repo gets into a state broken state and they need an "expert" to fix it.
Git is not a success story. Git is a failure as a system with a crap user experience that forces you to learn more about the tool you're using that about getting your work done.
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I've never understood the position that people shouldn't unionize because they're rich. You know who's even richer? Execs. Tech companies have monopsony hiring power and use it to capture most of the value of labor, enriching execs with mid 8 figure to mid 11 figure net worth.
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We lost candidates due to recruiter screens like this when I was at Google. Not sure why they persist in doing them.
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Where does engineering rep come from? Here's a Google engineer slagging on Amazon engineering, which they say mediocre. I don't think this is an unusual opinion, I've heard this from people both inside and outside of Google. Google has the best engineering, Amazon is mediocre.
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Great, practical, guide on how to write a successful library. When people talk about why X is great, most trendy topics are highly overrated and the topics in this post are highly underrated.
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This kind of thing is why the CPU startup I worked for allowed users to change the CPUID: you get huge performance gains from putting GenuineIntel in CPUID(0), but it would be a copyright violation to distribute our CPU with GenuineIntel in the CPUID.
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Want to write to your filesystem safely? No worries, the manpage has all the latest rumors
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Why don't more programmers work half-time? Proportionally, I know a lot more medical professionals (doctors, physios, etc.) who work half-time or less. I've heard people say it's hard to find part-time programming work, but everyone I know who's actually tried has succeeded.
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Twitter is, of course, mostly on prem. The now gutted HWENG group was so good at designing low power servers that, in a meeting with Intel folks, discussing reference designs vs. what Twitter was doing, the Intel folks couldn't believe the power envelope Twitter achieved.
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This might be the best written job posting I've seen. Not only do they disclose comp, they're candid about negatives
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That time a slashdot reader fixed a multi-day global Microsoft/hotmail outage by paying an overdue domain invoice.
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it's odd to have a set of policies that results in giving a huge number of people a very valuable education and then not allowing them to stay in the U.S. This is arguably good from a global equality standpoint because it reduces U.S. concentration of wealth & power, but.
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Offer numbers from someone with 5 years of experience, currently making $300k/yr. They consider offers of $500k/yr so low that they're not even worth mentioning. I shopped around a bit and have found similar, in that large companies are willing to offer me >= 2x what I'm making.
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Interesting comment about SGI leadership knowing about the problems they were facing and still being unable to come up with a way to handle them.
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It's funny how wrong basically every public take about Twitter from the commentary class is, e.g., here's a blue check who's a fellow at a think tank saying that all Twitter needs to do is pay its AWS bills (serving is on prem and most cloud spend is GCP) and it will run itself,
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Despite the market already seeming bonkers high then, it has gone way up since then. E.g., a friend of mine who was "senior" at Google (there 4 years with no promo) now makes $750k/yr and got a level bump for changing jobs after FB and another company got into a bidding war.
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This pair of blog posts that blows up the idea that you can benchmark by running a warm-up period and then taking the last N results without looking at the underlying data are some of the best performance blog posts I’ve ever seen:.
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A pattern it took me way too long to see is that people who are extremely mercenary and behave as if duty/loyalty/honesty/etc. don't matter to them often make extremely basic mistakes as a result of not understanding that other people aren't as mercenary as them.
A funny thing about the concerns about saboteurs, comments about lazy devs, etc., is how many people I've talked to who, just before they left, went the extra mile to make sure the site stays up as long as possible without intervention.
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Lots of people in my mentions saying things like "Elon is cleaning house! Lazy bums are getting what they deserve!", as if Twitter employees are getting a much deserved comeuppance. Since people don't seem to understand what the bums at are getting, here's a short primer:.
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A funny anti-pattern is that management track has better career prospects than IC track in expectation, leading people who want career advancement to switch to management when their IC career stalls out. On average, people I've seen switch for that reason are poor managers.
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This thread about math reminds me of a fallacy I frequently see in systems design, where some people believe that, because they've created simple primitives, the resultant systems that are built on top will be simple and easy to reason about.
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Interesting to see users working around the lack of tactile buttons in some modern cars:
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See also, automotive engineers fighting against designers who want headlights to look nicer but work less effectively and/or blind people in other vehicles:
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An interesting thing about this claim is that not only is the implication wrong, Twitter probably has better evidence of its wrongness than any other company in its size class could have.
Btw, I’d like to apologize for Twitter being super slow in many countries. App is doing >1000 poorly batched RPCs just to render a home timeline!.
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What are software "shims" or "tics" people use to work around hardware/software issues? Some examples of what I mean:. In the web's early days, I reflexively hit "select all; copy" constantly because apps would error out and browsers didn't preserve text when you hit "back".
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Funny to see VCs who generally rail against government intervention making the case for a bailout of Silicon Valley Bank now that there's an intervention that would directly help them and their friends. Socialism for me, capitalism for thee.
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People say you should work at startups because that's where the interesting work (and money) is. That's backwards!
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When I first heard this, I thought it was odd, but having since paid attention to what happens when VPs and directors attempt to communicate information downwards, I have to concede that it seems like the MS VPs were right and nuanced communication usually doesn't work at scale.
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I remember having conversations with people when I was in school (20y ago) about how these policies had to create thriving EE industries in other countries, causing problems for U.S. companies down the line. No one disagreed at the time and this played out exactly as predicted.
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Programming blogs e̶v̶e̶r̶y̶o̶n̶e̶ ̶m̶u̶s̶t̶ ̶r̶e̶a̶d̶ you might like:.
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Another leap second, another slew of outages. Handling time correctly is hard!.
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Of the best engineers I personally worked with in college (on class projects, etc.), all but one wanted to stay in the U.S. but wasn't allowed to due to visa rules. From my university's standpoint, international students were great because they paid high tuition/fees, but.
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The new stuff in the Twitter algorithm is wild. "author is elon", "author_is_republican", "author_is_democrat", etc., are explicit terms that are special cased.
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Some benefits of simple architectures. or, if you prefer a more exciting title,. The unreasonable effectiveness of simple architectures.
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reducing U.S. share of wealth/power seems antiethical to the goals of the people who are advocating for immigration limits which result in highly productive folks being forced to leave the U.S. (it aligns with other goals, but the impact of this one seems larger in the long run).
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The Twitter change where they switched everyone from their choice of timeline to ranked timeline reminds me of a question: why don't social media companies react to negative signals from users?. The change trained me to stop checking the app since it filled my feed with garbage.
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I wonder how much waste has been eliminated by Yann Collect creating zstd. When I ran the numbers at Twitter, which is tiny compared to the huge tech companies, switching to HDFS to zstd was ~ mid 8 figs/yr. Across the world (not annualized), it seems like must be >= 9 figs?.
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There are a billion active Android devices running an Android version that's two or more years old. Approximately 0% of those devices will get updated.
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I was shocked to find out that Steve Klabnik is the lowest paid person on the Rust team because of how obviously high impact his work is, but I guess I shouldn't be surprised considering how non-programming non-management work is compensated in tech.
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What successful (say, $1B+) tech companies use an architecture that's basically a monolith (as opposed to a service-oriented architecture)?. Some famous examples of this are Etsy ($20B) and Stackoverflow (acquired for $1.8B), but there are probably other examples?.
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The project led by the PM director who bragged about how many hours they work and sleeping in the office hit their deadline and shipped. The product charges people who sign up but it doesn't actually work. But they technically shipped. The best kind of shipped.
On one end, impressive that this new, verified feature got built and shipped in a week, people working 84 hour weeks. On the other: it doesn’t work. I’m a Twitter Blue subscriber. The new app tells me I now have a verified checkmark. But I don’t. Fast work, but sloppy work.
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I learned a lot in my 8-year long stint I couldn't have learned in 2 4-year long stints, and this recursively applies to every shorter duration I've worked. Seeing the real impact of decisions down the line has value for anyone who wants to build anything of lasting value,.
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But when I looked at execution speed on actual projects (via backchannel communications), AWS was smoking both us and Google. In one case, I heard that they got the idea for a project from our product announcement and they still shipped before we did.
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So, about that desperate covid-19 related shortage of COBOL programmers in NJ that I've seen written up in six different publications.
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It's interesting to see how "algorithm" has become a bogeyman among people who write about tech, even people who tend to be relatively well informed. It's as if people want "algorithm" to become the new "radiation".
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The fear was that if they said that they needed to ship fast and improve reliability, reliability would be used as an excuse to not ship quickly and needing to ship quickly would be used as an excuse for poor reliability and they'd achieve none of their goals.
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I find it funny that, looking at writing that's "about" productivity, there's overwhelmingly more written about tech/tooling choices than about emotional management (seems like at least 100:1) when emotional management dominates tech choices at typical margins in industry.
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I often marvel at the dynamic range of productivity that's out there. Once upon a time, a programmer wanted to make an online Dominion implementation, so they did it as a "weekend project". To this day, it's the nicest interface I've used for any online board game,.
IIRC, originally used some kind of fancy cloud-based solution and then switch to running on a single machine in the guy's apartment and had better uptime than most companies with fancy multi-AZ and multi-region setups.
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I think I failed an interview at FB a long time ago (~2013) because of this. The interviewer asked me how you can write deadlock free code, and I told him that there's this thing people say about taking/releasing locks in order, but there are places where that won't save you.
Same re: other properties you might think you have, like deadlock-freedom because you obey a proper lock hierarchy. In the model that's true, in actual reality the best you ever get is some statistical guarantees.
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When reading discussions about tech comp, people often talk past each other because they have different mental models. This thread is an attempt to convey some mental models that people who want higher compensation might have.
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I recently heard some advice from someone in eng leadership to an IC to avoid performance work since it's a career dead end. I find that interesting because it seems to me that performance work seems like one of the most straightforward ways to make "senior staff".
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There’s something I find unreasonably entertaining about seeing what memes, etc., people in other fields pass around, e.g., HVAC techs:
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LRTs: it's funny how frequently people leave because their employer forces them to interview elsewhere if they want market rate comp. I've heard the justifications for this, but if you do the math on this, I don't it works out even as a pure cost savings play.
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People who've worked at (non-dysfunctional) small companies describe what big companies feel like after having worked at a small company (h/t @hyperpape):.
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One of the funniest (to me) things I learned at Twitter was that peak global load is early in the morning in American zones because North American Twitter users use the site during work hours and Asian Twitter users use the site after work, so the alignment of those is peak usage.
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Has anyone made even a cursory attempt at figuring out false positive / negative rates for interviews?. I tracked down how well a number of people we rejected are doing in cases where I had some visibility into the rejection reason and the reason was wrong most of the time.
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