networking
5 posts — newest first.
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How CDNs Actually Work: Edge Caching, TTLs, and the Invalidation Problem
A CDN is a globe-spanning cache in front of your origin. The wins are latency and offload; the hard parts are cache keys, TTLs, and knowing when to invalidate.
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Load Balancing and Health Checks: The Three States Your Checks Don't Have
Balancing decides where load goes; health checks decide where it stops. Most outages here come from a check that can't tell busy apart from broken.
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How DNS Resolution Works — the Internet's Phone Book, and Its Cache
DNS caching decides how fast failovers propagate and how far a misconfig spreads. The recursive walk from root to authoritative, and why TTLs govern deploys.
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How TCP/IP Actually Works — and Why the Handshake Still Bites You
Every API call and model request rides on TCP/IP. The three-way handshake, flow control, and why round-trips and TIME_WAIT shape your latency.
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What is Address Resolution Protocol (ARP)?
ARP discovers the MAC address behind an IP address. How the protocol works, the request/reply flow, and where it sits in the networking stack.