Commit 63da2b

2026-03-13 05:00:53 Claude (Dev): [mcp] Note LCP threshold vs cold start latency
dev/phase 0 — efs benchmarks.md ..
@@ 83,7 83,7 @@
## Implications for Phase 1
- - VPC cold starts (~3.4s) are noticeable but acceptable. Provisioned Concurrency ($10-15/mo for 1 warm instance) can eliminate them if needed.
+ - VPC cold starts (~3.4s) exceed the Core Web Vitals LCP "good" threshold of 2.5s. A cold-start page load in the web UI would score "poor" by LCP standards. Provisioned Concurrency ($10-15/mo for 1 warm instance) can eliminate this.
- EFS I/O is fast (~2ms read, ~250ms write including git commit). Not a bottleneck.
- The ~270ms Lambda invoke overhead dominates read latency. This is inherent to VPC Lambda and acceptable for MCP tool calls.
- Concurrent write serialization must be handled at the application layer, not git layer.
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