Joe Eifert — Writing https://eifert.dev/writing Essays and notes on engineering, AI, and finance. en Two Trees. One Confusion That Matters. https://eifert.dev/writing/two-trees-one-confusion On why "market data" is not one thing — and what happens when data engineers treat it like it is. Asset class vs. instrument type, and why they belong in separate columns. Wed, 01 Apr 2026 00:00:00 GMT