see attached description.
Most information must be captured via the backend.
1) on the front end show all the categories
2) a category can be selected which will show a list of companies
3) a company can be selected which will show all items for that client.
4) if a company is signed in they can view all their own work and make changes to the data.
Clients & companies must be able to track their work.
You can use any language