Josh Pensky joshpensky

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

⇐ back to the gist-blog at jrw.fi

Advanced SCSS

Or, 16 cool things you may not have known your stylesheets could do. I'd rather have kept it to a nice round number like 10, but they just kept coming. Sorry.

I've been using SCSS/SASS for most of my styling work since 2009, and I'm a huge fan of Compass (by the great @chriseppstein). It really helped many of us through the darkest cross-browser crap. Even though browsers are increasingly playing nice with CSS, another problem has become very topical: managing the complexity in stylesheets as our in-browser apps get larger and larger. SCSS is an indispensable tool for dealing with this.

This isn't an introduction to the language by a long shot; many things probably won't make sense unless you have some SCSS under your belt already. That said, if you're not yet comfy with the basics, check out the aweso

How to Successfully Publish Your App on the App Store or Google Play

As someone who has released many apps starting in 2015 using frameworks such as Cordova and Ionic, and more recently using React Native and Expo, I have learned that the rules for publishing apps can change frequently and can sometimes be challenging to navigate. With that in mind, I want to provide a brief guide to help others navigate the process. While this guide may not cover every aspect of publishing an app, it does cover general tips and information that should be useful for anyone looking to release their app on the App Store or Google Play.

Metadata

Keywords, Description, Screenshots, App Name, Promo Videos

There are significant differences between Apple and Google when it comes to metadata. Apple is generally stricter than Google, so it is advisable to follow Apple's guidelines to ensure the best chances of success on both platforms. Here are some tips to keep in mind:

Keep your screenshots and promo videos separat

	<!DOCTYPE html>
	<html prefix="og: http://ogp.me/ns#">

	<head>
	<!-- content-type, which overrides http equivalent header. Because of charset, this meta should be set at first. -->
	<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
	<!-- Overrides http equivalent header. This tells IE to use the most updated engine. -->
	<meta http-equiv="X-UA-Compatible" content="IE=Edge">
	<!-- Tells crawlers how to crawl this page, and the role of this page. https://developer.mozilla.org/en-US/docs/Web/HTML/Element/meta -->
	<meta name="robots" content="index, follow">