Why My First Smurfing Alert Engine Missed a BDT 3 Million Rocket Ring—and How I Fixed It
AI-generated illustration Bangladesh, 03:12 AM. The BFIU dashboard flashes a red line: a burst of 27 transactions, each just under the BDT 100,000 MFS threshold, moving between five Rocket agent accounts in 45 minutes. The total? BDT 3,027,842. My heart skips. The alarm that should have screamed never did. I was staring at a structuring ring that had slipped through the cracks of our rule‑based engine. The Hidden Problem: Why Classic Threshold Rules Fail in Dhaka We all start with the obvious: set a hard limit at BDT 100,000, flag anything above. Works for big jumps, but not for the slow, steady drip that smurfs money across multiple agents. In Bangladesh the BFIU Circular 15/2023 explicitly calls out “multiple low‑value transfers to a single beneficiary within a short window” as a red flag, yet most AML platforms still treat each transaction in isolation. My first attempt was a naïve count‑per‑hour rule. If an account sends more than three transactions over BDT 95,000 within an hour...