[kovyrin]

Honestly, just as it is with many SAAS companies at some scale, we do not need care about any specific customer's traffic anymore. Simply because we get so much traffic already from our existing customers, that none of the new customers could generate enough to cause any significant blip on the radar. If a customer comes to us with some specific requirements (like being able to index 100MM documents with some specific response time guarantees), we build dedicated pieces of infrastructure for them, load-test it all and provide those guarantees. All of the others are placed in their own pools which have enough capacity to handle 3-5x of ALL of our current traffic with no issues, so any single customer would not be able to generate enough load to cause problems.

And, as I mentioned in the article, we could always order new boxes for any of our clusters and get them online within a couple hours, so we are able to scale up pretty quickly if needed.