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Post-Mortem

How One Bug Cost Me
Over $7,000 on Google Cloud

Aug 15, 2025 Joselito Bacolod

Gusto kong i-share sa inyo ang isa sa mga pinakamalaki at pinakamasakit na pagkakamali na nagawa ko sa career ko. Ito yung kwento kung paano ako nagising isang araw na may bill na umaabot sa higit $7,000 (halos ₱417,000) mula sa Google Cloud.

Normal na araw, chineck ko yung billing para sa "Kapilya Near Me". Para akong binuhusan ng malamig na tubig. Biglang umakyat sa libo-libong dolyar ang bill sa loob lang ng isang araw. Halos lahat ng gastos, galing sa iisang service: Distance Matrix API.

Cost Breakdown

99% of the cost came from a single API.

The Culprit Code

The `applyFiltersAndRender` loop caused an N+1 issue.

Ang akala kong simpleng feature ay naging financial nightmare. Ang problema: sa bawat pag-click ng user sa filter, tumatawag ito sa getTravelTimes para sa LAHAT ng locations sa listahan. Kung may 100 na Locals, isang click lang ng user, 100 API calls agad 'yon! Ito ay umabot ng 1.4 million requests sa isang araw.

Critical Lessons

Billing Alerts

Set budget alerts. If I had an alert at $10, I would have known immediately.

API Quotas

The "kill switch." Set hard limits on requests per day. Better to error out than go bankrupt.

Batch Requests

Avoid N+1. Batch multiple destinations into a single API call whenever possible.

Update August 18, 2025

The Aftermath: Account Lockout

With VAT, the total hit $7,133.38. As of today, my entire Google Cloud billing account is locked.

Impact Radius

This didn't just affect Kapilya Near Me. It took down Bacolodwebdev.com, Bahanearme.com, Somedaycapsule.com, and client projects linked to the same billing account. A painful lesson in having a single point of failure.

I am currently migrating sites and negotiating with Google Support for a "goodwill credit." Stay tuned for the resolution.

Happy coding, and be a responsible dev!

Set your billing alerts today.