Migrating our UI and API to use Puma

[syphax-bouazzouni]

Description:

To improve performance and maintainability, we should migrate our Rails UI and Sinatra API from Passenger and Unicorn servers to Puma server.
Puma is now the standard for Rails and Sinatra apps due to its better concurrency handling, lower memory usage, and cloud compatibility.

Definitions:

• Passenger: A web and application server known for its ease of use and integration with Nginx/Apache.
• Unicorn: A forking web server optimized for Rails but limited to process-based concurrency.
• Puma: A multi-threaded and multi-process web server designed for better performance and scalability.

Feature	Unicorn	Puma	Passenger 5
Clustering	Yes	Yes	Yes
Multithreaded	No	Yes	Enterprise Only
Slow client buffering	No	Yes	Yes
ActionCable	Yes	Yes	Yes
Support	Open Source	Open Source	Open Source / Paid
Installation	Gem	Gem	Binary or Gem
Zero-Downtime Deploys	Yes	Yes	Enterprise

Reasons for Migration:

• Performance & Scalability: Puma's hybrid model handles concurrency better.
• Memory Efficiency: Uses fewer resources compared to Unicorn.
• Active Development: Puma is actively maintained, unlike Unicorn.
• Simplified Deployment: Less overhead compared to Passenger.