I am working on re-designing an existing Spring Boot application which is trying to automate a series of executions of work that the company is currently having done manually by it's staff. It has a main application that works almost as an orchestration application in the sense that it is the service that will call other applications to get the overall piece of work done. It has 7 sub-systems that it invokes, 3 of these systems need to be invoked in some form of order and complete before the other 4 are invoked but they can be invoked asynchronously.

All of these sub-systems have now been moved to Spring Microservices and the application I'm working on must invoke these microservices (some in order and some asynchronously), it is possible that my application will be called more than once at the same time so I need to consider that multiple containers may be needed for each sub-system. I've implemented Open-Feign to invoke each of the Microservices.

They also have the plan in the not so distant future to move this to AWS ECS/Fargate, however for the time being it is going to be run in Linux VM's and the containers are created on the same private network for communication. I'm wondering if I should remove ThreadPoolTaskExecutor completely and just invoke a new container for each simultaneous request to my application, however I've read that threads on a process are still faster and have less overhead than creating a process on a container and considering there's not going to be many containers invoked simultaneously I'm perplexed as to the best approach.

Any advice would be appreciated.