Shelf

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We had to choose where to host a PostgreSQL database on AWS and the choice was between plain AWS RDS, AWS Aurora for PostgreSQL, and AWS Aurora for PostgreSQL Serverless v2.

At first, we were skeptical about Aurora Serverless v2 as past experience with Serverless v1 showed major drawbacks in terms of autoscaling performance.

But after some testing on a couple of hundreds of gigabytes of data, we were convinced Aurora Serverless v2 is the way to go.

It delivers all the promised instant scaling capabilities and provides unparalleled disk IOPS performance, up to millions of IOPS if needed.

Aurora Serverless V2 can truly handle whatever data volume you have and run even the most complex queries without doing much optimization in advance. Of course, later down the road, it gives you detailed performance metrics to help with optimization. It is similar to MongoDB in this regard - easy to start with, don't worry about structure/volume in the beginning, but you got all the tools to optimize it later.

Compared to MongoDB it offers predictable performance, infinite scalability, outstanding stability, and tiny cost.

When using MongoDB at scale, you encounter all sorts of issues that are not advertised in MongoDB promotional materials. You get limited by the number of connections, not compatible drivers, and unexpected bugs in new releases.

With MongoDB, it's easy to get started quickly because it doesn't require you to think about data structure in the beginning. When you hit a certain scale you either spend months reengineering your DB or paying loads of cash to scale your cluster.

On the other hand, DynamoDB is much limited in its querying API, but that's a good thing. It's very hard to build a not scalable or low-performance database with DynamoDB. Also, you get all the perks of native integration into other AWS services.

Back in 2018, we were running microservices in the ECS cluster by managing EC2 instances ourselves. It involved lots of toil work.

Without Fargate we had to maintain & monitor a pool of spot instances, choose the right size of instances, keep OS up-to-date, etc.

We want to ship features, not to manage servers. That's why as soon as AWS Fargate was announced, we migrated our microservices to this managed service. The only configuration you need is Docker image, RAM & CPU resources. The rest of the heavy lifting is taken care of by Fargate, which is wonderful.