You can also look up for these other topics:
Framework
Coding Standards
Boilerplate
CMS
Tool
Security
Hacktoberfest
Symfony bundle to isolate your app's doctrine database tests and improve the test performance
Doctrine2 behavior traits that help handling Blameable, Loggable, Sluggable, SoftDeletable, Uuidable, Timestampable, Translatable, Tree behavior
Doctrine2 behavioral extensions
Symfony2/3/4/5 Queue Bundle (for background jobs) supporting Mongo (Doctrine ODM), Mysql (and any Doctrine ORM), RabbitMQ, Beanstalkd, Redis, and ... {write your own}