Frontend

Upgrading

Update the ember-source and ember-cli package to the next LTS version.
After updating the these two packages update every package which is related to them (See Ember documentation https://guides.emberjs.com/release/)
Then check the browser console and remove all deprecations and errors step by step, if necessary update other packages
After you removed all errors and deprecations push your branch and check if any tests fail
If yes fix the tests if no add your coach as reviewer to the pr

EMBER-AUTO-IMPORT: If the ember-auto-import package has to be updated, check its documentation, if you're upgrading from ember 3.28 to 4.x be aware that the ember-auto-import stores your dependencies in multiple chunk and that you have to reconfigure webpack to create one chunk with an absolute path to reference in your application.
STRATEGY: At the start of each day, write a checklist of which points you have to do today and write a step-by-step strategy on how you're going to solve your problems this helps keeping track of all the upcoming errors and can be extremely useful to other developers which have to help you.
REBASING: An update takes usually longer than just a day especially if you upgrade ember to a major version. Because of that you shouldn't forget to rebase at the start of each day, why you are upgrading the ember version other developers implement features and it can be really frustrating to rebase ALL the features your colleagues have coded at the end of your upgrade.