You might be able to monetize through closer partnerships with companies like Microsoft, Atlassian, Amazon, etc.. I'm envisioning an ad system that is basically geared towards selling their cloud and DevOps services. Because the engine is geared towards programming queries, you might also entice these companies by showing that developers have an easier time troubleshooting their systems. Perhaps, eventually, the engine could be bought out and act like a loss-leader or funnel to services. I know Microsoft is trying to be very developer friendly.

Just some random thoughts. Monetization is a huge bootstrapping challenge for something like this.