AWS Lambda SnapStart & Cold Start Optimization (2025) cloudaura Infrastructure Team January 27, 2026 54 min read The Hidden Cost You Didn't Know You Were Paying The August 2025 Billing Change On August 1st, 2025, AWS quietly started billing you for something that used to b aws lambda cold startlambda snapstartprovisioned concurrencylambda performance optimizationlambda init billinglambda memory tuninglambda power tuningarm64 lambda