LeeStack — Writing by David LeeDeep technical notes and architectural essays on software engineering.https://leestack.dev/SQLite vs. PostgreSQL: A Production Engineering Decision Frameworkhttps://leestack.dev/writing/sqlite-vs-postgresql-framework/https://leestack.dev/writing/sqlite-vs-postgresql-framework/A systems-level breakdown of SQLite and PostgreSQL — concurrency models, WAL mechanics, failure modes, and when the conventional wisdom is wrong.Sun, 26 Apr 2026 00:00:00 GMTMental Models for Distributed Systemshttps://leestack.dev/notes#mental-models-for-systems/https://leestack.dev/notes#mental-models-for-systems/A quick reference for reasoning about consistency, availability, and failure domains.Sun, 26 Apr 2026 00:00:00 GMTSQLite on the Edge: Performance Noteshttps://leestack.dev/notes#sqlite-on-the-edge/https://leestack.dev/notes#sqlite-on-the-edge/Observations from running Turso and Cloudflare D1 in production environments.Sat, 25 Apr 2026 00:00:00 GMTWhy I'm Moving Core Logic to Rusthttps://leestack.dev/notes#why-rust-for-core-logic/https://leestack.dev/notes#why-rust-for-core-logic/The trade-off between iteration speed and runtime safety in critical path code.Fri, 24 Apr 2026 00:00:00 GMTInside LinkedIn's AED System: How 6,167 Extension Probes Build a Device Dossierhttps://leestack.dev/writing/linkedin-aed-systems-analysis/https://leestack.dev/writing/linkedin-aed-systems-analysis/A backend engineer's breakdown of LinkedIn's Active Extension Detection system — the fingerprinting pipeline, the data model, the distributed surveillance architecture, and what it means when a platform weaponizes browser primitives against its own users.Thu, 02 Apr 2026 00:00:00 GMTNASA’s Rules for Code That Can’t Fail — Revisited for AI-Generated Systemshttps://leestack.dev/writing/nasa-rules-for-code-that-cant-fail/https://leestack.dev/writing/nasa-rules-for-code-that-cant-fail/Applying NASA's legendary JPL flight software discipline to modern backend infrastructure and the era of AI-generated code.Wed, 18 Mar 2026 00:00:00 GMTWhy Content Firsthttps://leestack.dev/notes#why-content-first/https://leestack.dev/notes#why-content-first/A short note on avoiding premature app complexity.Fri, 16 Jan 2026 00:00:00 GMTSQL Window Functions in Production: What the Tutorials Don't Tell Youhttps://leestack.dev/writing/sql-window-functions-production/https://leestack.dev/writing/sql-window-functions-production/Window functions aren't just a cleaner syntax for analytics. Understanding their execution model, cost profile, and failure modes is what separates a working query from one that takes down your reporting replica.Sat, 17 May 2025 00:00:00 GMTGo Maps Never Shrink: Diagnosing Heap Retention in Production Serviceshttps://leestack.dev/writing/go-maps-never-shrink/https://leestack.dev/writing/go-maps-never-shrink/A production postmortem on Go's map memory model, why deleting keys doesn't reclaim heap, how this compounds in long-running services, and what Rust's HashMap design teaches us about explicit control in backend systems.Sun, 13 Apr 2025 00:00:00 GMT