Atishay Kasliwal — Writing 2026-07-14T00:00:00.000Z https://atishaykasliwal.com/ Atishay Kasliwalhire@atishaykasliwal.com Your backtest is lying to you https://atishaykasliwal.com/blog/point-in-time-correctness 2026-07-14T00:00:00.000Z 2026-07-14T00:00:00.000Z Point-in-time correctness is the difference between a financial ML pipeline that works and one that only appears to. Here is where the leaks hide and how to design them out.