How do you run your BETA programs for your software?

My process:

• Collect beta signups via landing page with MailChimp form
• Send out invite urls that have an invite code attached. Even though invite code looks random, everyone gets the same invite code. It just sets a cookie that's read client-side and renders the app if it's correct. No need to overengineer.
• Invite beta participants to a private forum or Slack to give feedback.
• Try to schedule calls with as many beta testers as possible to learn more about them and their experience.
• Spend as little time as possible in beta. Launch publically a few weeks later unless there are major issues that need to be addressed.

I am developing JPEG artifacts removing tool and for Beta version:

1. Tested it myself as much as possible. Using diverse data as an input and near to target domain.
2. Asked friends / mates from IT to test it for free / personal usage. Sometimes it works.
3. Posted links at betafy and website like that, but has no traffic / response from them.

And yeah, for testing purpose I also publish demo-version with quite restricted functionality hoping someone will write a feedback :)