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Recent Posts
System Design: Ad Exchange (Real-Time Bidding, Sub-100ms Auctions, DSP/SSP, Impression Serving)
System Design
Apr 10, 2026 · 59 min
System Design: E-Commerce Flash Sales (10M Users, Coupon System, One-Per-User Enforcement)
System Design
Apr 5, 2026 · 106 min
System Design: News Aggregator (100K Sources, Dedup, Personalized Ranking)
System Design
Apr 5, 2026 · 86 min
Leadership
ManagerEngineering Roadmaps
“Outcome-based roadmaps outlast feature-based ones. Define what success looks like, not just what to build”
Org Design
GrowthEngineering Career Ladders
“IC and management tracks should run parallel in seniority and comp. A Staff Engineer and an Engineering Manager should be peers, not one reporting to the other”
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Discover Today
Google S2 Geometry
The spherical geometry library behind Google Maps, Spanner, and every serious geospatial system
Linkerd
Built on linkerd2-proxy, a purpose-built Rust proxy that uses roughly 30MB per sidecar compared to Envoy's 100MB. Smaller memory footprint, fewer moving parts.
Quorum Systems & NRW Notation
With N replicas, W (write quorum) and R (read quorum) define the consistency tradeoff. If W + R > N, every read sees at least one replica with the latest write because the write and read sets must overlap