The survey was done by interviewing 11,000 interviewers. They also answered some other questions, including what programming languages they used, favorite frameworks and salary.
Packt Publishing also found that the income of web developer is not the direc proportion to the popularity of programming languages. For example, The annual average salary of Bash, Perl, Scala web developers is over $80,000, while PHP and C web developers is under$ 40,000.
In terms of tools used by web developers, AngularJS ranks first. Followed React.js frameworks of Facebook, Node.js, Docker, Laravel, Bootstrap, WordPress and AWS.
The most popular programming languages in a few years ago were Swift, C#, Go, Rust and Elixir. The most popular new Frameworks are Docker, Apache Spark, Amazon Web Services, Hadoop, Azure, Xamarin and so on.