My session done at DrupalCamp Montreal 2018 about a high speed workflow for Drupal 7 and 8 with Composer, NPM and Lando.

So you want to edit a specific piece of code provided by a class from Drupal's core or from a contrib module?

...

You just need a few lines of Javascript to automatically filter all your Views in Drupal.

Basically, we use the great Lazy Builder provided by Commerce Cart module. Easy peazy!

Menus are very specials in Drupal 8 - and sometimes very frustrated too!
Learn how to filter menu items by the current user's language in Drupal 8.

I a few word, it's been a mix of luck and sweat.