I built a Twilio / Goggle Cloud DialogFlow integration last year. It was my first experience with both Twilio or Google Cloud. The client says it’s been working well, but the Twilio bills have been abnormally high.

Anomaly in Billing

I found what appears to be the culprit (see attached image), but can’t track down the cause. These don’t align with any sort of peak usage times and I didn’t see anything in the call logs that coordinate with these spikes. They occur maybe 2% percent of the time, but are responsible for 90% of the cost.

Is anyone familiar with what might be causing this, or what direction I should take to dig further into the issue?