Modules in Magento can be located in two places – /app/code and /vendor. Let’s consider what is the difference between them and where it is right to develop your modules. TLDR: it depends on the number of projects in your company.
Varnish can fail not only because of misconfigured transient cache. It can fail because of bugs, for example in using libexecinfo. Sometimes you can see that Varnish’s child process fails and you lose all the cache due to it.
If you need to copy emails from one mailbox to another, even if they are located on different servers, you can use the imapsync utility. You just need to install and run it in the console with parameters. Naturally, you need to know the passwords for both mailboxes.
Fluentbit can follow and parse logs and send them to different systems, for example, Newrelic or Elasticsearch. But you may notice, that for some reason it does not follow files or stops follow ones.
As you know, Varnish is a powerful caching system and it is a must-have on every Magento setup, even at the development workstation. But there is a little trick that very few people know about. It is the Transient cache, which I explain below.