Welcome HN. Technology is about tradeoffs. Using Postgres for everything is a tradeoff. Of course you use the right tool for the job. Often this is Postgres. Helping dozens of startups I have seen many more people overcomplicate setups than companies that use tools that are too simple for the job. If you have 1M+ customers, and 50+ developers, and you need Kafka and Spark amd Kubernetes, go ahead. If you have more systems than developers, just use Postgres. Thanks to Hugo and BunnyCDN for keeping the page fast. PS: Postgres for everything doesn’t mean one server for everything ;-)
TLDR; just use Postgres for everything.
We have invited complexity through the door. But it will not leave as easily.
There is Radical Simplicity though.
One way to simplify your stack and reduce the moving parts, speed up development, lower the risk and deliver more features in your startup is “Use Postgres for everything”. Postgres can replace - up to millions of users - many backend technologies, Kafka, RabbitMQ, Mongo and Redis among them.
Use Postgres for caching instead of Redis with UNLOGGED tables and TEXT as a JSON data type. Use stored procedures to add and enforce an expiry date for the data just like in Redis.
Use Postgres as a message queue with SKIP LOCKED instead of Kafka (if you only need a message queue).
Use Postgres with Timescale as a data warehouse.
Use Postgres with JSONB to store Json documents in a database, search and index them - instead of Mongo.
Use Postgres as a cron demon to take actions at certain times, like sending mails, with pg_cron adding events to a message queue.
Use Postgres for Geospacial queries.
Use Postgres for Fulltext Search instead of Elastic.
Use Postgres to generate JSON in the database, write no server side code and directly give it to the API.
Use Postgres with a GraphQL adapter to deliver GraphQL if needed.
There I’ve said it, just use Postgres for everything.
As a CTO, Interim CTO, CTO Coach - and developer - Stephan has seen many technology departments in fast-growing startups. As a kid he taught himself coding in a department store around 1981 because he wanted to write video games. Stephan studied computer science with distributed systems and artificial intelligence at the University of Ulm. He also studied Philosophy. When the internet came to Germany in the 90 he worked as the first coder in several startups. He has founded a VC funded startup, worked in VC funded, fast growing startups with architecture, processes and growth challenges, worked as a manager for ImmoScout and as a CTO of an eBay Inc. company. After his wife successfully sold her startup they moved to the sea and Stephan took up CTO coaching. You can find him on LinkedIn, on Mastodon or on Twitter @KingOfCoders