AWS ECS Expert for Infrastructure Fix

We have a Python Flask app running on ECS. It serves all our traffic but we've started to see tasks de-provision or stop in the middle of the day causing customer downtime. Our customers expect 0 downtime as they are operating fast retail environments and our systems being down mean loss of revenue. We've been boarding more customers and have noticed this issue has started to become more frequent. We're looking for an expert to take a look at our current setup and help resolve issues / ensure high uptime. We are also looking to hire for future work / maintainability as well as backend optimization. However, at the moment, our biggest concern is ensuring that we stop having downtime.