Functions concurrent execution

Please Help Appwriters

My project is in a scenariot where we need to automatically create two functions for each user we have. The purpose of these functions is to provide autonomous services for our users. Let's call the two functions A et B.

The A function can take up to 3 minutes to complete execution. The B function can take up to 1 minute to complete execution.

Both functions are triggered by CRON. For function A, it's every 5 minutes, and for function B, it's every 4 hours.

The problem is that I've noticed that not all the A functions manage to run, or sometimes the only run one after the another, starting with the first ones we've created. Only the very first functions we created manage to run every 5mins. The others have to wait indefinitely.

Assuming we have 1,000 users, it's clear that customers will almost never get their service.

We're plannig to have 600,000 users. That's 600,000 x 2 appwrite functions == 1.200.000 functions that need to execute every 5 mins.

I'd like to know how we can set up parallel execution of the functions.

We are self-hosting and have the ability to grow server specs at will.

Thank a lot