/Dan Luu

Willingness To Look Stupid tl;dr: “The benefit from asking a stupid sounding question is small in most particular instances, but the compounding benefit over time is quite large and I've observed that people who are willing to ask dumb questions and think "stupid thoughts" end up understanding things much more deeply over time. Conversely, when I look at people who have a very deep understanding of topics, many of them frequently ask naive sounding questions and continue to apply one of the techniques that got them a deep understanding in the first place.”

featured in #546


How Web Bloat Impacts Users With Slow Devices tl;dr: “Modern pages that burn a ton of CPU when loading could be doing pre-work that means that later interactions on the page are faster and cheaper than on the pages that do less up-front work, but that's not the case for pages tested, which are slower to load initially, slower on subsequent loads, and slower after they've loaded.”

featured in #500


In Defense Of Simple Architectures tl;dr: Dan discusses the effectiveness of simple architectures in software development, using Wave, a $1.7B company, as an example. Wave's architecture is a Python monolith on top of Postgres, allowing engineers to focus on delivering value to users. The article emphasizes that simple architectures can be created more cheaply and easily than complex ones, even for high-traffic apps. Despite the trend towards complex, microservice-based architectures, Dan argues for the "unreasonable effectiveness" of monoliths, detailing Wave's choices, mistakes, and areas of unavoidable complexity. Simplicity in architecture can lead to success, allowing companies to allocate complexity where it benefits the business.

featured in #439


The Container Throttling Problem tl;dr: "At Twitter, most CPU bound services start falling over at around 50% reserved container CPU utilization and almost all services start falling over at not much more CPU utilization even though CPU bound services should, theoretically, be able to get higher CPU utilizations." This document describes potential solutions. 

featured in #278


Willingness To Look Stupid tl;dr: Dan believes the "compounding benefit" and ROI of asking a stupid sounding question is quite large and those willing to ask them "end up understanding things much more deeply over time," despite the fear many feel doing so. Dan provides examples of such questions.

featured in #263


What To Learn tl;dr: "Look for things you can't help but do that most other people don't seem to do." It's common to try and improve all of your skills or "know a bit of everything" but, try to turn a skill into a superpower and "amplify your strengths." Dan also notes the importance of finding the right environment for this to happen.

featured in #261


The Value Of In-house Expertise tl;dr: "Twitter has a kernel team!?" Everyone is surprised to learn this but, as Dan explains: "a company Twitter's size is going to regularly run into kernel issues... without a kernel team or the equivalent, the company will muddle through the issues, running into unnecessary problems as well as taking an unnecessarily long time to mitigate incidents."

featured in #260


A List Of Post-mortems! tl;dr: Dan links to many public post-mortems by both small and large companies.

featured in #210