If I know how to use Postgres as a relational DB, it does not mean that I know how to turn it into message queue. I guess I can build some kind of implementatio

If I know how to use Postgres as a relational DB, it does not mean that I know how to turn it into message queue. I guess I can build some kind of implementation but that would take time to research and implement it. And I can spend that time to implement RabbitMQ. Which is likely million times more popular than Postgres for this particular task, so I'll have more information. I don't agree to this post. One should use old, proven and stable solutions. If you need message queue, you need rabbit MQ. If you need cache, you need Redis. Don't implement non-standard non-conventional solutions if you can avoid it. Find out what's industrial standard and use it. Avoid dying solutions, avoid new solutions. But also remember that you should have something unique. You don't want your business to be easily repeated by someone, because you will compete to margin zero. It's not necessarily tech thing. But it might be tech thing. You don't build cloudflare using off-the-shelf nginx.