If you are using lando and xdebug, you need to make sure that your docker-php-ext-install all go through (https://docs.lando.dev/guides/installing-php-extensions-on-lando.html#_…), otherwise xdebug might not be installed properly, after that also make sure xdebug setting is

To fix this problem you will need to unistall cmdinstall and then put yarn, if not it will keep calling cmdtest, this is even on newer ubuntu 20.x versions.

sudo apt-get remove cmdinstall;sudo apt update;sudo apt-get install yarn

If you updated your environment to php 7.3 or higher, there is a good chance you will have default syslog settings that is syslog.filter set to no-ctrl 
http://php.itronic.at/manual/en/errorfunc.configuration.php#ini.syslog…;

To check current rsyslog version, run this in terminal

rsyslogd -N1

So we had "503 Max restarts limit reached" problem on our production while doing some batch operations and some edits of entities. Problem for both was that server response was slow as both have large queries running which take more than 20 seconds(yeah should be optimized and probably add some indexes to fields).

Calling this 3 commands should help you install qcachegrind so you can read xdebug profiler files you made

# Install qt
brew install qt

# Install qcachegrind
$ brew install qcachegrind
 
# Install graphviz
$ brew install graphviz

run qcachegrind in CLI and it will open up app in window where you can import profile file.

You want to keep composer quite and just do its job? Then either set that to your composer.json config with

composer config --global discard-changes true

Which will add that config to your config.json and everbody will have this setting or you can just make this one liner to keep it shut.

To get all crontabs from users on your system write this one liner

for user in $(getent passwd | cut -f1 -d: ); do echo $user; crontab -u $user -l; done

to check other crons you need to see what is in for example 

ls -la /etc/cron.daily

or

I will just link to 2 good articles how to do this

https://www.bounteous.com/insights/2020/03/11/automate-drupal-deployments/
https://chromatichq.com/blog/drupal-8-deployment-scripts

To login to drupal and POST/PATCH some endpoint over JSON:API you need to login first, this is simple over postman, just go to Authorization TAB, select Basic Auth and fill in your user/pass and this will be automatically added to your header. You could also make it manually adding header with calculated base64 username:password, which you can get with CLI and