If your website is based on PHP and is being served by Apache web server with Nginx as reverse proxy, then you may have experienced 504 Gateway Timeout errors. The error usually happens because some PHP script takes longer than usual to run.
Jekyll is a static site generator. It generates static HTML pages from content written in Mark Down or HTML. Its different from other website publishing tools in that it does not use a database.
The Google Chrome developers toolbox is a useful tool that can be used to test HTTP POST requests. For example we may want to replay HTTP requests for testing APIS or debugging web pages.