I have been developing websites and web applications for more than 15 years now and I wanted to list the top 10 situations where I spent (or wasted?) a lot of time debugging or managing a situation where the root cause was tricky (or stupid?).
Google has just launched a great certification program called “mobile sites” where they advocate for their vision of how mobile websites should be designed and optimized to improve the user experience. It gives some interesting statistics on page size and loading speed that everyone involved in website development should know.