title: 500 error when using AWS API gateway as webhook
body: <p>I am trying to use AWS Lambda function with API gateway endpoint as weebhoks. The problem is that after a few requests I get 500 (or sometimes 503) errors. In Cloudwatch I can see that the request does not even trigger Lambda. So API gateway throws the errors. If I am waiting a short time then it everyhting is working fine again.</p>
  <p>In Cloudwatch of API gateway I can only see the error status, no more.</p>