Somersoft has worked in these areas of DevOps
Building
The use of composer and package libraries reduces the amount of code that is stored in code repository. Composer can invoke other programs like npm, a JavaScript package manager, which in turn can invoke other programs like node-sass to compile SASS into CSS. This can consistently build the application from all the sources.
Developer Environment
The use of environments like Docksal provides a local OS independent environment for all developers.
Code Quality
Add code quality checks into the developer's workflow using programs like PHPCS and PHPunit for PHP, eslint for JavaScript and csslint for SASS/CSS. There is also Rector to check code is sustainable. This functionality can be used on an ad-hoc basis by the developer, or on commit to the source code repository or by the central source code repository.