Where do you find actual active developer communities on Discord/Slack? (No dead servers please)

Been trying to network and learn from other devs, but keep finding dead/spam-filled servers. Looking for active tech communities where people actually talk and help each other.

What I'm looking for:

- Active daily discussions

- Mix of juniors and seniors

- Code review channels

- Job opportunity sharing

- Project collaboration

What I've tried:

- Random Discord listings (mostly inactive)

- Generic "programming" servers (too broad/noisy)

- Public Slack workspaces (hit or miss)

Questions:

  1. Which Discord/Slack communities do you actively participate in?

  2. How did you find them?

  3. Red flags to watch out for?

  4. What makes a dev community worth staying in?

Bonus: Any niche communities for specific tech stacks?

Thanks for all the responses! I'm compiling a list of verified active communities in the comments.