Bookmarks (3751)

How does Linux's display work? Linux has an amazing yet frustrated at the same time about display. Xorg, Xserver, X11, KDE, Gnome, Xfce…The full dekstop environment can easily swap out. That multitude can be overwhelming or confusing when we don’t have the full picture. There are multiple documentations for each side of the Linux’s display system, but globally how does it work exactly?

I replaced Google Analytics with a web server running on my phone Your phone is a mini computer with low power consumtion, and if you add the SIM, it maybe come a great device to be always online. What if we run a web server on that device and open it to the internet. What kind of programming language will be easily to be deploy and run on the phone.

Race Conditions/Concurrency Defects in Databases: A Catalogue Categorize concurent transaction issue: Dirty Read, Dirty Write, Read Skew, Lost Update, Write Skew.

What's a key exchange? Key exchange is fundamental in any secure connection, at some point it will have a key exchange that only two partners know so no one can see what they are communicate. This post is an attempt to explain this process in a simpler way.

Building Cloudflare TV from scratch Cloudflate TV is like a TV show where you tune in to watch their engineers talk about programming. Cloudflare has great blog posts we link many time in the past too. They want a solution as simple as joining a Zoom call. They laid out technical challens when building an infrastructur for that.

Inside Code Signing This is probably a post for mobile dev. However, most of time the one who setup build/release for a mobile app maybe a devops/backend engineer. Therefore, understanding code signing process on iOS is really important. Even if you don’t have to deal with this at all, it’s still a good read to understand how iOS control this process.

Improving performance with SIMD intrinsics in three use cases SIMD (Single Instruction Multiple Data) is an instruction set available mostly on all current processors. SIMD instructions give data-level parallelism on a unit (vector of data). A single instruction is executed in parallel on multiple data points as opposed to executing multiple instructions. That improves the performance. People use SIMD to parse JSON faster or process image. In this post, we learn about 3 use cases to make use of SIMD for great peformance

A completed game and a tutorial to build it step by step A replayable arcade shooter with a focus on build theorycrafting. Use a massive skill tree, many classes and ships to create your own builds and defeat an ever increasing amount of enemies. The tutorial includes 15 parts: game loop, room and areas, player stats and attacks, enemies, skill tree and more.

Building Domain Driven Microservices touched upon various concepts, strategies, and design heuristics to consider when we venture into the world of microservices, more specifically when we try to break a monolith into multiple domain-based microservices

Bitcoin from scratch - Part 1 Understanding the fundamental building blocks(😉) of Bitcoin can be daunting for some developers. I find it difficult to meaningfully understand a system without knowing how everything fits together. Someone on Hacker News also wrote a toy implementation of the Bitcoin algorithm in Node so you can even test mining in browser.

Scaling Linux Services: Before accepting connections When writing services that accept TCP connections, we tend to think of our work as starting from the point where our service accepts a new client connection and finishing when we complete the request and close the socket. For services at scale, operations can happen at such a high rate that some of the default resource limits of the Linux kernel can break this abstraction and start causing impact to incoming connections outside of that connection lifecycle. This post focuses on some standard resource limitations that exist before the client socket is handed to the application.

Containers from first principles Dig into container. Docker image are just tar file with some meta data. A container needs at least: network stack, file system, processes. So how can we re-create that, using simple bash commands?

Beginner’s Guide To Abstraction In The Pragmatic Programmer, Andrew Hunt and David Thomas introduced the DRY (Don’t Repeat Yourself) principle But then Sandi Metz came along and said: Duplication is far cheaper than the wrong abstraction. So what should we do

Types of Indexes in PostgreSQL B-Tree index is the default index. But you know we have no one size fit all data structure for fast look up. What if we just want an exact match? Well, a hash index might faster there.

The Double-Bang (!!) Operator And A Misunderstanding Of How JavaScript Handles Truthy / Falsy Values I have been reviewing more JS code recently and saw this a lot. Here, Ben Nadel shows why they aren’t needed and when they are needed(In a comment though).

SCALING THE HOTTEST APP IN TECH ON AWS AND KUBERNETES Hey email app is getting a lot of attention recently. Partly because it is created by DHH, creator of Ruby on Rails, who has a strong opinion on avoiding SPA JavaScript and focus a lot on Ruby. He used to avoid public cloud like AWS or GCP and belive it’s more cost effective on bare metal. But in one podcast I heard 2 years ago, he hinted that eventually the cloud will be cheaper enough and it makes sense to use cloud by then. Here, we will see their infrastructure, initially starting with GCP, then migrate to AWS EKS. They made use a lot of managed service

SSH Emergency Access with certificates A guide to setup SSH authentication with certificates instead of pub key. Why? Certificate allow you to set expiration date, centralization control and revoke easily. With normal public key, once got in, users can added their own key and do whatever they want.

Reshaping JSON with jq teaches how to use the command-line utility jq to filter and parse complex JSON files into flat CSV files. If you need a play ground for jq, check out jqplay.

Real-World Cryptography The author wants it to be the best book in this field. It’s free to read online right now on Manning so check it out(You have to register for a free account to read though). It has 11 chapters so far. Learning about cryptography definetely help you along the way to understand thing like TLS, PGP etc

Performance/Avoid SQLite In Your Next Firefox Feature This is an 2014 document of FireFox project to advise their engineer to avoid SQLite, they explain the downside of SQLite at that time, which may not right in 2020. However, I found many things still ring true such as the IO pattern. I recently have to debug a small SQLite database with heavy disk IO due to its fsync in default rollback-journal mode

The Definitive Guide to Linux System Calls If you ever use chown, chmod, or even doing any file read, or mkdir, you are making system calls. System calls are how a progrm enters the kernel to perform some tasks. This guide teachs us User programs, the kernel, and CPU privilege levels, Interrupts(kind of like event that is generated by hardware or software), then how we can craft system calls using assembly. A very low-level guide but I found it’s very helpful and easy to follow to know more about our computer.

Reading files the hard way But what is a file, really? And what does reading a file entail, exactly? See how it’s done in Node, C, Rust, Strace, x86 asm, look to disk layouts, ext4