The main problem with AWS Fargate, as with most of AWS's offering, is cost. More precisely, granularity. AWS Fargate cost infrastructure, at best, charges you

The main problem with AWS Fargate, as with most of AWS's offering, is cost. More precisely, granularity. AWS Fargate cost infrastructure, at best, charges you per ceiling of 0.25 vCPU and 0.5GB of RAM (rounded up) per second, with a ceiling of 2GB of RAM. If your containers have some spiky workloads that require more than 2GB of RAM then the coarseness goes up and your are charged per 1GB of RAM (rounded up) per second. That means a spiky workload can lead you to spend more than a month's worth of a EC2 instance with 2GB of RAM (say, T3.small with 2vCPU and 2GB of RAM). The whole service becomes even more ridiculous if a company is already operating EC2 instances or even kubernetes clusters on EC2 spot instances (the topic of this discussion), because more often than not these workloads can be already covered by the cluster's unused capacity.