Over the past years, I have been aiming at achieveing complete per tenant file isolation in production. My aim was to be able to track individual/company uploaded files with ease, sometimes enforce storage quota limits per user/company and track their usage for proper billing. I wrote series of S3 and R2 wrappers in order to achieve this and stay organized. I couldn't find what I wanted from other cloud storage providers, most of them gave me a single bucket where I just dropped everything and then wrote the isolation, tracking and billing logics from scratch. Now we have Tenantbox which gives your application per-tenant file storage, quota enforcement, and usage tracking in just two API calls.