No GPS Required: Our App Can Now Locate Underground Trains
tl;dr: “Thanks to our clever engineering, we can now predict your location in a subway tunnel using your phone’s vibration signature.” This post dives into how.featured in #568
How Passwordless Authentication Works - A Deep Dive
- James Walker tl;dr: Passwordless authentication is a better option than traditional passwords, improving security and increasing convenience by removing the challenges associated with passwords. James explains how passwordless works using methods like magic links, biometrics, or one-time codes, and the benefits it provides engineering leaders and CTOs.featured in #544
How Passwordless Authentication Works - A Deep Dive
- James Walker tl;dr: Passwordless authentication is a better option than traditional passwords, improving security and increasing convenience by removing the challenges associated with passwords. James explains how passwordless works using methods like magic links, biometrics, or one-time codes, and the benefits it provides engineering leaders and CTOs.featured in #535
How Apple Accidentally Broke My Spotify Client
- Roberto Frenna tl;dr: “I turned on my work laptop and started catching up on everything that happened during my absence. Music makes this process more enjoyable, so I started up Spotify and started playing some tunes. I was very surprised (and mildly pissed) when playback abruptly stopped and Spotify seemingly went offline.” Roberto dives deep to understand the issue.featured in #483
Abracadabra: How Does Shazam Work?
- Cameron MacLeod tl;dr: Shazam does the following to register a song: it calculates a spectrogram of a son, extracts peaks from that spectrogram, pairs those peaks up into hashes and stores the collection of hashes for a song as a fingerprint. Cameron discusses these in depth, as well as how Shazam recognizes an audio sample and matches it against its database.featured in #472
The Case Of A Curious SQL Query
- Justin Jaffray tl;dr: Justin provides a deep dive into SQL's foundational aspects, highlighting the importance of a formalized approach to query behavior. Using the example of "predicate pushdown," Justin presents a SQL query that behaves differently across databases like DuckDB, SQLite, and CockroachDB. "I think it's a fun little mind bender that gives you some insight into the internals of these databases query engines without having to actually look at any code."featured in #460
Inside New Query Engine Of MongoDB
- Nikita Lapkov tl;dr: A significant overhaul of the Query Execution Engine has been announced. The article provides an in-depth look into the technical aspects of this change. The previous engine, termed "Classic," was built around JSON documents, leading to inefficiencies in complex queries. The new Slot Based Engine (SBE) introduces "slots" as a means to pass data, optimizing the process. Nikita delves into the architecture, data flow, and challenges faced during the transition.featured in #449
In A Git Repository, Where Do Your Files Live?
- Julia Evans tl;dr: Julia explores the inner workings of git, specifically how it stores files in the .git/objects directory. Through Python programs, Julia investigates the location of specific files and their older versions discovering "content addressed storage," where the filename is the hash of the file's content. The article also demystifies the encoding process, showing that files are zlib compressed, and emphasizes that git stores complete files, not just the differences.featured in #449
UK Air Traffic Control Meltdown
- James Haydon tl;dr: During a routine deployment, NATS, a major UK-based air traffic management company, experienced a significant system disruption. This "meltdown" led to widespread operational challenges. The root cause was identified as a misconfiguration introduced during the deployment. James dives into root causes of the issues that caused 1,000 flights to be cancelled.featured in #448
Building A ShopifyQL Code Editor
- Trevor Harmon tl;dr: “This approach enabled us to provide ShopifyQL features to CodeMirror while continuing to maintain a grammar that serves both client and server. The custom adapter we created allows us to pass a ShopifyQL query to the language server, adapt the response, and return a Lezer parse tree to CodeMirror, making it possible to provide features like syntax highlighting, code completion, linting, and tooltips. Because our solution utilizes CodeMirror’s internal parse tree, we are able to make better decisions in the code and craft a stronger editing experience. The ShopifyQL code editor helps merchants write ShopifyQL and get access to their data in new and delightful ways.”featured in #448