Google AI Classroom Part 1: Solving the $25-Per-Exam Problem — Architecting a Sub-$0.02/Student Serverless AI Classroom with Gemini 4 & Firebase
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Serverless AI classroom architecture with cost analysis, actionable for cloud engineers.
A Hong Kong institute built a serverless AI classroom on Google Cloud that keeps per-student exam costs under $0.02 by running 95% of proctoring inference locally in the browser using WebGPU, WebAssembly, and on-device models like Gemma 4 E2B and Whisper-Tiny. The 4-tier hybrid architecture uses Firebase for real-time signaling, Cloud Functions Gen 2 for event-driven compute, and reserves Gemini 4 Argon and Gemini 3.5 Flash for pedagogical synthesis and rubric grading. This eliminates the $15–$25 per-exam cost of commercial proctoring while addressing academic integrity in the AI era without streaming raw video to the cloud.