Any good recommendations for A/B testing frameworks? Server/client side (JavaScript in either case) preferred!

How can a total noob start building simple machines?

I am interested into building machine but I don’t know where to start. I have basic knowledge about JavaScript and Python. Is there any resources that could help me start?

Do long CSS selectors make page rendering slow?

I've heard that having really long selectors in your CSS makes your page rendering slow. Since I'm used to using SASS, so I always end up having really long selectors. Something like this: .parent .child .element .child .child2 .child3 .child4 .child...

When should you use flexbox?

I recently got into an argument with a co-worker where he blamed me for making a component too complex by using flexbox. His argument was that flex rules like justify-content: space-between might behave unexpectedly when you're manipulating the eleme...

Would it be a good idea to perform animations with CSS variables?

I’ve heard people saying CSS variables can be used in an intelligent way and that you can change your variable value real time to achieve animations (something like this). I’m interested in knowing if this manipulation of CSS variables would be perfo...

How do you optimize website assets & reduce load time?

I constantly find myself optimizing assets to improve efficiency. I try to keep the file size to a minimum without compromising on quality but sometimes I find this a challenge. I was wondering if you guys have any pointers when working with assets f...

Why do we even have vendor prefixes in CSS?

We use vendor prefixes in CSS when a property is not fully supported everywhere and write something like: .div { display: -webkit-box; display: -webkit-flex; display: -ms-flexbox; display: flex; } instead simply writing display: flex;...

How do you clearfix?

Clearfix are used to avoid elements collapsing into each other and is usually done by just adding an extra div with clear:both rule. What’re some other ways of applying clearfix? also, is it a good practice to use clearfix?

Implementing instagram like filters using CSS?

I'm trying to enhance some images on my website and photoshopping is just too much of effort, is there any way I can implement instagram like filters using CSS?

How do you make a clock animation like in Google IO event page?

Demo. Any suggestions?