It's common to see people advocate for learning skills that they have or using processes that they use. For example, Steve Yegge has a set of blog posts where he recommends reading compiler books and learning about compilers. His reasoning is basically that, if you understand compilers, you'll see c...

A common topic of discussion among my close friends is where the bottlenecks are in our productivity and how we can execute more quickly. This is very different from what I see in my extended social circles, where people commonly say that velocity doesn't matter. In online discussions about this, I ...

An alternate title for this post might be, "Twitter has a kernel team!?". At this point, I've heard that surprised exclamation enough that I've lost count of the number times that's been said to me (I'd guess that it's more than ten but less than a hundred). If we look at trendy companies that are w...

A question I get asked with some frequency is: why bother measuring X, why not build something instead? More bluntly, in a recent conversation with a newsletter author, his comment on some future measurement projects I wanted to do (in the same vein as other projects like keyboard vs. mouse, keyboar...

In the classic 1986 essay, No Silver Bullet, Fred Brooks argued that there is, in some sense, not that much that can be done to improve programmer productivity. His line of reasoning is that programming tasks contain a core of essential/conceptual1 complexity that's fundamentally not amenable to att...

I've been comparing notes with people who run corporate engineering blogs and one thing that I think is curious is that it's pretty common for my personal blog to get more traffic than the entire corp eng blog for a company with a nine to ten figure valuation and it's not uncommon for my blog to get...

My hobby: opening up McIlroy’s UNIX philosophy on one monitor while reading manpages on the other. The first of McIlroy's dicta is often paraphrased as "do one thing and do it well", which is shortened from "Make each program do one thing well. To do a new job, build afresh rather than complicate ol...

If you read any personal finance forums late last year, there's a decent chance you ran across a question from someone who was desperately trying to lose money before the end of the year. There are a number of ways someone could do this; one commonly suggested scheme was to buy put options that were...

Reaching 95%-ile isn't very impressive because it's not that hard to do. I think this is one of my most ridiculable ideas. It doesn't help that, when stated nakedly, that sounds elitist. But I think it's just the opposite: most people can become (relatively) good at most things. Note that when I say...

When I ask people at trendy big tech companies why algorithms quizzes are mandatory, the most common answer I get is something like "we have so much scale, we can't afford to have someone accidentally write an O(n^2) algorithm and bring the site down"1. One thing I find funny about this is, even tho...

This is a psuedo-transcript for a talk given at Deconstruct 2019. To make this accessible for people on slow connections as well as people using screen readers, the slides have been replaced by in-line text (the talk has ~120 slides; at an average of 20 kB per slide, that's 2.4 MB. If you think that...

A recurring discussion in Overwatch (as well as other online games) is whether or not women are treated differently from men. If you do a quick search, you can find hundreds of discussions about this, some of which have well over a thousand comments. These discussions tend to go the same way and inv...

This is an archive of the original "fsyncgate" email thread. This is posted here because I wanted to have a link that would fit on a slide for a talk on file safety with a mobile-friendly non-bloated format. From:Craig Ringer <craig(at)2ndquadrant(dot)com> Subject:Re: PostgreSQL's handling of fsync(...

I've had this nagging feeling that the computers I use today feel slower than the computers I used as a kid. As a rule, I don’t trust this kind of feeling because human perception has been shown to be unreliable in empirical studies, so I carried around a high-speed camera and measured the response ...

A statement I commonly hear in tech-utopian circles is that some seeming inefficiency can’t actually be inefficient because the market is efficient and inefficiencies will quickly be eliminated. A contentious example of this is the claim that companies can’t be discriminating because the market is t...

It's common knowledge that Android device tend to be more out of date than iOS devices, but what does this actually mean? Let’s look at android marketshare data to see how old devices in the wild are. The x axis of the plot below is date, and the y axis is Android marketshare. The share of all devic...

About once a month, an app that I regularly use will change its UI in a way that breaks muscle memory, basically tricking the user into doing things they don’t want. Zulip In recent memory, Zulip (a slack competitor) changed its newline behavior so that ctrl + enter sends a message instead of insert...

We’re going to reproduce some results from papers on filesystem robustness that were written up roughly a decade ago: Prabhakaran et al. SOSP 05 paper, which injected errors below the filesystem and Gunawi et al. FAST 08, which looked at how often filesystems failed to check return codes of function...

If you look at “gaming" keyboards, a lot of them sell for $100 or more on the promise that they’re fast. Ad copy that you’ll see includes: a custom designed keycap that has been made shorter to reduce the time it takes for your actions to register 8x FASTER - Polling Rate of 1000Hz: Response time 0....

This is a pseudo-transcript for a talk on branch prediction given at Two Sigma on 8/22/2017 to kick off "localhost", a talk series organized by RC. How many of you use branches in your code? Could you please raise your hand if you use if statements or pattern matching? Most of the audience raises th...

I recently had a problem where part of the solution was to do a series of pointer accesses that would walk around a chunk of memory in pseudo-random order. Sattolo's algorithm provides a solution to this because it produces a permutation of a list with exactly one cycle, which guarantees that we wil...

There’s a great MSR demo from 2012 that shows the effect of latency on the experience of using a tablet. If you don’t want to watch the three minute video, they basically created a device which could simulate arbitrary latencies down to a fraction of a millisecond. At 100ms (1/10th of a second), whi...

Which is faster, keyboard or mouse? A large number of programmers believe that the keyboard is faster for all (programming-related) tasks. However, there are a few widely cited webpages on AskTog which claim that Apple studies show that using the mouse is faster than using the keyboard for everythin...

I often talk to startups that claim that their compensation package has a higher expected value than the equivalent package at a place like Facebook, Google, Twitter, or Snapchat. One thing I don’t understand about this claim is, if the claim is true, why shouldn’t the startup go to an investor, sel...

A couple years ago, I took a road trip from Wisconsin to Washington and mostly stayed in rural hotels on the way. I expected the internet in rural areas too sparse to have cable internet to be slow, but I was still surprised that a large fraction of the web was inaccessible. Some blogs with lightwei...

HN comments are terrible. On any topic I’m informed about, the vast majority of comments are pretty clearly wrong. Most of the time, there are zero comments from people who know anything about the topic and the top comment is reasonable sounding but totally incorrect. Additionally, many comments are...