Instrumenting Google Apps Script with OpenTelemetry
Google Apps Script powers a surprising amount of business infrastructure.
Approval workflows, hiring pipelines, invoice generators, CRM integrations
— all running as serverless functions triggered by form submissions, chat
messages, or time-based triggers. When something breaks, you get a
stacktrace in the Apps Script logs and nothing else. No traces, no
metrics, no correlation between the email that failed and the spreadsheet
write that succeeded two seconds earlier. You're debugging with
Logger.log and guesswork.
We run a hiring automation bot on Apps Script that touches Gmail, Sheets, Drive, Calendar, GitHub, and Google Chat in a single command invocation. When a candidate's assignment email silently failed to send, we had no way to tell whether the issue was the template fetch, the Gmail API, or the spreadsheet update that stores the thread ID. The execution log just said "success." This is the story of how we instrumented it with OpenTelemetry.
