Thanks for those links but they mentioned their codebase is full of legacy code. I talked about what they use on their PHP stacks and they mentioned they don't

Thanks for those links but they mentioned their codebase is full of legacy code. I talked about what they use on their PHP stacks and they mentioned they don't use any frameworks at all. They use AngularJS for their front-end but on the PHP side they use pure PHP and no frameworks at all.