I think the PostgreSQL community gets this right. The only deadlines are if you want your feature in the upcoming release, or if you can wait another year. See

I think the PostgreSQL community gets this right. The only deadlines are if you want your feature in the upcoming release, or if you can wait another year. Seems to be paying off quite well. What other database can ship reliably every year with major new features and all kinds of improvements on many axes? And people still say the code is readable and the reliability is solid.