A from-scratch tour of Bitcoin in Python
Usually when programming we call a public api on an object and the real works are being done. We don’t know exactly what happen under the hood. Imagine you read a file, you call
fseek but that’s that. Who move the hard drive tip? who fetch the data from hard drive and put it to memory so your program can access it? The way to know that is working directly with the protocol instead of relying on the SDK. Today, we do the same with Bitcoin. It’s written by Tesla AutoPilit director
Serving sharp images to high density screens
in 2010 the iPhone 4 came out, and the screen was 640×960, whereas the similar-sized iPhone 3 was 320×480. The resolution doubled, while the screen size was roughly the same, so in effect the screen density doubled. Apple couldn’t just run the same apps but at a higher resolution, because things like text and buttons would be tiny, so they doubled the size of everything. 1 pixel became 2 ‘device pixels’. On the web we call this the ‘device pixel ratio’, or DPR. The iPhone 4 had a DPR of 2. This is sometimes referred to as having a 2x screen, or 2dppx. So you see the mess?
Why mimicking a device is becoming almost impossible
Simply change the user-agent of device just trick simple system. But it isn’t simple like that because a device also share many information such as screensize. And these parameters can be used to figured out the real device model.
r/WallStreetBets Incident Anthology
WallStreetBets and the Gamestop incident causes spike in Reddit traffic and cause internal dependency failure cascaded as the core systems started degrading due to the database performance issues.
Code to read
Resize image in browser with high quality and high speed
The smallest CommonMark compliant markdown parser with positional info and concrete tokens.
a feature rich logging framework, and replacement for existing Ruby & Rails loggers.
is a campaign mailer for Rails. If you run a SaaS, it can be useful to schedule timing campaign for users. Stuff like send first email after signup. second emails after 2 days etc
Dozens of minimal operating systems to learn x86 system programming. Tested on Ubuntu 17.10 host in QEMU 2.10 and real hardware
Terminal-based, hyper-fast, CRDT-backed, collaborative note-taking tool
Hide your scrapers IP behind the cloud. Provision proxy servers across different cloud providers to improve your scraping success.
High-performance, columnar, in-memory store with bitmap indexing in Go
Add a floating virtual IP to Kubernetes cluster nodes for load balancing easily.
Command-line admin tool for observing and troubleshooting Postgres.
a simple and efficient HTTP mock server. Define request/response in Yaml
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