Amplewillow
Independent coverage of infrastructure, networking and data practice.
Reading Latency Percentiles Without Fooling Yourself
July 13, 2026
Mean latency figures obscure the critical tail behavior that quantile measurements highlight. An API exhibiting an average response time of fifty milliseconds can still subject five percent of requests to two-second delays; those unfortunate visitors encountering cold starts, cache misses, and saturated shards generate support complaints.
Evaluating quantiles requires understanding distributional nuances. Comparing 95th percentile metrics before and after releases is valid only when underlying traffic compositions remain unchanged; a surge in heavy reporting queries skews tail figures without representing true performance degradation. Similarly, evaluating 99th percentile numbers over narrow 60-second intervals captures fleeting noise rather than structural patterns.
Why Edge Caching Still Matters in 2026
August 8, 2026
Industry commentary regularly claims that fast compute and cheap bandwidth render perimeter caches unnecessary. High-percentile latency measurements prove otherwise every single week. When a client in Sao Paulo requests data from an origin in Frankfurt, physics imposes an unavoidable transit penalty…
Practical Notes on Postgres Connection Pooling
September 11, 2026
Handling PostgreSQL backends imposes substantial overhead because each active client spawns a dedicated process consuming significant RAM, making intermediary connection management mandatory at scale. While session-level pooling preserves compatibility seamlessly, transaction pooling aggressively re…
Email Deliverability: Authentication Beyond SPF
April 24, 2026
Traditional SPF checking fails to address modern deliverability challenges on its own. While an envelope IP check might succeed, mismatched headers trigger spam filters that prioritize cryptographic DKIM validations and broader DMARC policy rules.…
HTTP/3 and QUIC: What Changed for Operators
September 12, 2026
QUIC moves the transport into userspace and encrypts most of the header, which is lovely for privacy and mildly annoying for anyone debugging with tcpdump. Flow control and congestion data that used to be visible on the wire now live behind the TLS key log.…
More reading
- Understanding TLS 1.3 Session Resumption — Security, May 2, 2026
- What Good Observability Actually Looks Like — Operations, September 11, 2026
- Zero-Downtime Deployments Without the Drama — Operations, May 21, 2026
About us
Our contributors have spent years on-call for large platforms. This site collects the playbooks, postmortems and reference material we wish someone had handed us earlier.