The blog post announcing the forum contains the details. Relevant excerpt:
Here is what you can do to get the Pioneer Badge.
- Head to the forum and click Log In. You’ll be authenticated with your algolia.com account, or prompted to log into Algolia if you weren’t already.
- Introduce yourself on the introductions thread.
- Tell the community about what you’re working on in the Projects category.
Do these steps by January 31, 2017 and this lovely hand-crafted badge created by @sebastien.navizet shall be yours. Among other things, the badge guarantees you entry to certain Algolia events even when they’re full.