Bubble API or C# API which is suitable for connecting Desktop App and Database

Hi, I’m new to Bubble. I’m a full-stack developer, I recently created a time tracker desktop application. I have to do many computations similar to below for my desktop app, when I do that my desktop app becomes very slow so I’m planning to do those calculations in an API so that I can reduce the load on the desktop app. I’m thinking of using Data API or Workflow API in Bubble.

The desktop application is WPF C# application
The database is MySQL hosted in the cloud

My requirement is, I will store data in database like
User ID - 101; Start Time- Jan 1, 2021 10 AM ; End Time - Jan 1, 2021 11 AM
User ID - 101; Start Time- Jan 3, 2021 09 AM ; End Time - Jan 3, 2021 11 AM

The database might have 100+ records for a User ID. The Bubble Backend API should calculate the time taken. In the above case the time taken is 3hrs.
	Expected API response = { "user_id":"101", "total_work_hrs" : "3hrs" }		
	Is it possible for Bubble to calculate and provide a similar response? If possible kindly please share some links for my reference.
	Or is it better to create a C# API instead of using Bubble? Please guide me. Thanks in advance.