Connor McDonald posts an excellent series of articles about tuning a database application. This analysis from a end user perspective reminded me of my own experiences when I was a technical consultant helping customers running a large CRM application, typically in call centres scattered across Europe. I was often summoned onsite and told to solve the problem that ‘The application is slow’. Usually, different people were eager to give me their view on the issue:-

I tend to switch Linux distributions quite often. Consequently, I tend to have this process down to a fine art and it doesn’t take me that long. The most time consuming element is ensuring the necessary backups are in place. However, you normally find some package or configuration option you forgot about and my recent switch from Arch Linux to Fedora 29 and back again unearthed a strange problem with the Dovecot IMAP server I hadn’t encountered before.