I need a RUBY Developer

I'm searching around for a RUBY expert. I own a small personal training gym and had a developer build a ruby system for me last year. The main purpose is to relace our outdated excel system. The function being to enable trainers to enter in completed/charged client training sessions into an online timesheet (client name and date of session), that data that auto dumps into client accounts which clients can log in and view to see completed/charged sessions and also see their payments they've made and see how many prepaid sessions they have left or how overdue they are. I also have an admin panel where I can enter payments clients have made (which, again, auto dumps over to those client accounts). In ADMIN I can also add new clients, client rates (many rates), Trainers, trainer rates, payments and payment info etc. After a year, the developer finally presented a system that works enough that we switch off the old excel system. Unfortunately the new system still has issues and the developer seems to take about 2 months per each edit to come up with a patch or solution which only partially addresses the issue. I need a reliable expert to work with going forward