We are using MESA to keep our Shopify customer database in sync with an external custom system. This is something Shopify Flow is not able to accomplish. Overall, MESA is a powerful solution. It lacks robust documentation, and there is a lot of trial and error, but MESA support staff is very responsive and helpful. One major omission for MESA is their ability to handle branching (if/then/else logic). But this can be overcome by building separate workflows. This can increase the monthly cost, though, as cost is based on the number of workflows active as well as the number of executions. I can wholly recommend this solution as others fall short.
Very useful app to automate based on many triggers but it still missing Google sheets reverse triggers and actions
It has a very quick & supportive customer service team :)