I wonder how they're doing this, are they invoking the Lambda functions using the synchronous API, or are they using something like API gateway? From what I ca

I wonder how they're doing this, are they invoking the Lambda functions using the synchronous API, or are they using something like API gateway? From what I can tell API gateway costs $3.50 a month per 1m calls, so unless they've negotiated some deal with AWS or something...