[IsTom]

I might be holding it wrong, but last time I tried to use DynamoDB it made absolutely no sense performance-wise to me. Postgres on my laptop was many orders of magnitude faster for fraction of price. It seemed like it maybe might make sense when you hit multiple TBs of database data and can no longer run on a single server? But then the costs would be sky-high and you probably could engineer your way around this with this kind of money.

[rushcar]

When you do a DynamoDB write it's replicating that write to 2 other datacenters before ACK (for availability + durability reasons). Your local Postgres instance doesn't need to make any network hops at all.

DynamoDB handled >100M qps during prime day, and its storage is effectively infinite. You don't have to self manage sharding, failover, CDC, etc.

disclaimer: I work for AWS (but not on DDB)

[sudosteph]

It's hard to do apples to apples performance with postgres - it really does depend on the data model and how you interface with it, but the thing about performance for DDB is that it can be very consistent. Pricing also depends a lot on your access patterns and data structures.

For me though, it's not having to worry about DB uptime, performance, or version updates that keeps me reaching for DDB even for small hobbyist stuff. But I'm also comfortable architecting for it, probably more comfortable than I am for traditional dbs, so that's a huge part of it.