Model selection is an architecture decision

Stop Asking “Which LLM Is Best?” – Ask Which Model Fits This Workload Last quarter I was elbow‑deep in a fintech product that had to turn noisy bank statements into clean expense reports. My first instinct was to grab the “biggest” LLM, fire‑off GPT‑4, Claude‑2, Gemini‑1.5 and hope it would magically understand every column, currency and weird abbreviation. After a weekend of latency checks, cost tallies and exploding error logs I realized the “best” model on every public leaderboard still missed our real KPI: cost per successful parsing. The fix was to stop treating LLMs like shiny toys and s