Past, Present and Future of Resource Loading
summary
Resource loading is slow because of measurable steps — DNS/TCP/TLS handshakes, server TTFB (often ~450 ms), slow start (initial congestion window ≈14 KB), discovery and deep dependency trees, queuing and bufferbloat, contention across connections, and bloat. Practical fixes already exist: QUIC removes head‑of‑line blocking and enables server‑side prioritization, BBR reduces bufferbloat and improves throughput, use preload/preconnect and h2 push with cache digests responsibly, and consider web packaging and Brotli (≈30% smaller) for cross‑resource compression.
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chapters (24)
- 0:00Start
- 3:29time != (bytes / BW)
- 4:02Latency!
- 7:26Why is loading slow?
- 10:29Slow Start
- 14:20Priority HTML CSS JS Fonts Images
- 22:46Queueing
- 23:50Packet loss HOL
- 24:10Priority responsiveness
- 25:22X-resource compression
- 31:34H2 compression dictionaries
- 32:45Web Packaging
- 33:54Server side processing
- 34:34Flush early
- 37:46Cache Digests
- 42:50Priority Hints
- 44:23Connection coalescing
- 45:50Non- credentialed connections
- 48:15Responsive Images & Client Hints
- 48:27What's in the future?
- 49:02What do I actually need to do?
- 49:18Use Push, Preload and Preconnect
- 49:28Unshard your domains Coalesce your connections
- 49:38Load only what you need
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