The Customization Guide is helpful while wanting to adapt Sylius to your personal business needs.
Customizing Models
Customizing Forms
Customizing Repositories
Customizing Factories
Customizing Controllers
Customizing Validation
Customizing Menus
Customizing Templates
Customizing Translations
Customizing Flashes
Customizing State Machines
Customizing Grids
Customizing Fixtures
Customizing Fixture Suites
Customizing API
Tips & Tricks
See also
All the customizations can be done either in your application directly or in Plugins!