In the year 2000 Roy Fielding’s acclaimed dissertation introduced the Representational State Transfer (REST) software design criteria, focusing on a series of constraints to simplify and standardize web services development. Although these guidelines were not immediately adopted as the norm, they paved the way for today’s petabyte-scale web architectures. Before exploring the principles behind REST APIs and high scalability, an overview of how the web works is required, with specific attention to its most popular protocol — HTTP.

I. HTTP- the winged messenger

If the World Wide Web were explained through Greek mythology (its precursor in complexity), the HyperText Transfer Protocol would be the winged…