I often like to have streams of trials playing in the background when I am working, and the recent trial of interest was the trial of Karen Read, who was accused of murder. One issue in this case was a conflict between two timestamps logged by different apps on a potential suspect's phone. Apple health had logged the …

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A guilty pleasure of mine is the pursuit of perfection. It is certainly a vice in most contexts, but there are some problems whose solutions demand a measure of perfection. These are problems that I will refer to as "5-9 problems": problems whose solutions need five 9's (or more) in some dimension. Usually, those nines …

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This account comes from several publicly available sources as well as accounts from insiders who worked at Knight Capital Group at the time of the issue. I am telling it second- or third-hand. On August 1, 2012, Knight Capital fell on its sword. It experienced a software glitch that literally bankrupted the company. …

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As you build a computer system, little things start to show up: maybe that database query is awkward for the feature you are building, or you find your server getting bogged down transferring gigabytes of data in hexadecimal ASCII, or your app translates itself to Japanese on the fly for hundreds of thousands of …

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A modern CPU is an incredible machine. It can execute many instructions at the same time, it can re-order instructions to ensure that memory accesses and dependency chains don't impact performance too much, it contains hundreds of registers, and it has huge areas of silicon devoted to predicting which branches your …

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A lot of ink is spent on the "monoliths vs. microservices" debate, but the real issue behind this debate is about whether distributed system architecture is worth the developer time and cost overheads. By thinking about the real operational considerations of our systems, we can get some insight into whether we actually …

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Python and Assembly have one thing in common: as a professional software engineer, they are both languages that you probably should know how to read, but be terrified to write. These languages seem to be (and are) at opposite ends of the spectrum: One is almost machine code, and the other is almost a scripting …

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