Get It Delivered

Get It Delivered is a Leicester based food delivery platform same like (Uber Eats , Deliveroo). I already have 2 Customer Apps (Andriod & iOS), 2 Delivery Patner/Driver Apps (Andriod & iOS) and 1 Outlet Panel for restaurants/takeaways. I want to update and maintain as an when necessary the whole project with new features, UI, Stability, Reliability, Customer friendliness. The system should be developed in such a way that it meets the highest possible standards and quality (E.g Uber Eats). The current technology used to developed the system is core PHP, MySQL, Server Scripting technologies etc. I want it to be designed and developed in such a way that scalability is taken into top consideration and is almost bug free. Also to maintain it in a streamlined manner.