feat: increase webapp Lambda memory from 512MB to 1024MB#116
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Increase the Lambda function memory size to improve cold start performance. Based on measurements across 887 requests (116 cold starts), 1024MB is the sweet spot: 3x faster cold starts (21.7s → 7.1s P50) and 32% cost reduction due to lower billed duration. Changes: - Update memorySize from 512 to 1024 in webapp.ts - Update CDK test snapshots - Update README cost table Closes #101
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Summary
Increase the webapp Lambda function memory from 512MB to 1024MB to improve cold start performance.
Problem
With 512MB (0.29 vCPU), Next.js cold starts take over 20 seconds due to CPU-bound operations (JS bundle parsing, DNS resolution, TLS handshake).
Measurement Results
1024MB is the sweet spot: 3x faster cold starts and 32% cost reduction due to lower billed duration.
Changes
cdk/lib/constructs/webapp.ts: memorySize 512 → 1024Closes #101