Impressive! Really fast, full featured code search across a huge corpus.

1. How did you build the index? Did you use a GitHub dump of some sort? How often do you refresh it?

2. Is it Elasticsearch or similar or a completely custom engine?

3. What kind of RAM/CPU are you using to power it?

4. Any plans to open source the code or commercialize the technology?

I could absolutely imagine paying for a private code search engine like this to run against a large internal company codebase spread across many repositories.