happy to answer this with direct customer quotes from the companies you mentioned. all of these quotes are public:

"We chose PlanetScale to host our most demanding Vitess and Postgres workloads, doing millions of queries per second on hundreds of terabytes of data." – Sualeh Asif - Chief Product Officer @Anysphere (Cursor)

"Moving to PlanetScale added a 9 to our uptime." - Brian Scanlan @Intercom https://x.com/brian_scanlan/status/1963552743294967877

"In the past we've had issues when something unusual happens on a specific shard, resulting in spiked CPU and poor performance, and since migrating we haven't really seen instances of this, speaking to PlanetScale choosing the correct hardware for our existing load at the outset." - Aaron Young, Engineering Manager @block

It seems like you are reaching pretty hard to find an issue with this statement. Your comment seems to come from a lack of experience scaling databases and not understanding how difficult it is to do what we've done in partnership with our customers. Either that or deep or a high level of insincerity.

> instead of emphasizing how they just couldn't scale past their previous limits.

We are not saying that our customers don't have the knowledge or expertise to do what we do. Many of our customers, including the ones mentioned above, have exceptionally high levels of expertise and talent.

Even so, it is not a contradiction to say that we allowed them to scale beyond their previous limits. In some cases those limits were that their previous DBaaS providers simply lacked the ability to scale horizontally or provide blazing fast reads and writes the way we do out of the box. In other cases, we offer a degree of reliability and uptime that exceeded what customers' previous DBaaS could provide. Just two name a couple of limits customers have run into before choosing PlanetScale.

Expertise and know-how, and actually doing the thing, are different. Many of our customers who are technically capable of doing what we do would simply prefer to focus their knowledge and expertise building their core product, and let the database experts (that's us) do the databasing.

> Are they implying these other companies lacked knowledge and expertise to put their databases on machines with NVMe storage?

Have you worked at any web dev companies? Of the ones I’ve been at, precisely one had any desire to run their own DBs, and deaf was more out of necessity due to poor schema design needing local NVMe just to stay afloat.

Yes, most web companies lack the experience to touch a server, because their staff are all cloud-native, and their CTOs have drank the Kool-Aid and are convinced that it’s dangerous and risky to manage a server.

Planetscale used to run postgres on AWS with network attached storage. So every time the DB hits the disks > it goes over the network. Need to read 4kb > network, another 4kb > network. So your latency is instead of microsecond on local storage, its miliseconds. Where a local NVME can do ... 100k 4k reads, over the network storage it does maybe 1k (just a example).

The problem is, there are not a lot of solutions to scale postgres beyond a single server. So if your DB grows to 100TB ... you have a issue as AWS does not provide a 100TB local NVME solution, only network storage.

Here comes Niki or whatever they named it. Their own alternative to Vitess (see Mysql), what is a solution that allows Mysql to scale horizontally from 1 to 1000's of servers, each with their own local storage.

So Planetscale made their own solution, so they can horizontal scale dozens, hundreds of AWS VPS with their own local storage, to give you those 100, 200, 500TB of storage space, without the need for network based storage.

There are other solutions like CockroachDB, YukubyteDB, TiDB that also allow for horizontal scaling but non are 100% postgres (and especially extensions) compatible.

Side node: The guy that wrote Vitess for Mysql, is also working on multigress (https://multigres.com/), a solution that does the same. Aka Vitess for postgres.

So yea, hope this helps a bit to explain it. If your not into dealing with DB scaling, the way they wrote it is really not helpful.

sharded setup with a bit fast and loose foreign key management, so very good for performance but not a drop-in replacement if you rely on your foreign keys to be constrained/checked by the database.

The short answer is that RDS doesn't run on local NVMe disks, it runs on EBS.