Logging Predictions & Ground Truth

Day 72 of 100 Days of MLOps. You can't monitor what you don't record. Today you build the foundation of every monitoring system: log every prediction your model makes — inputs, output, timestamp, model version — to an append-only file, then later join it with the true outcome when it arrives. Once prediction and reality sit in the same row, you can measure how right the model really was. It's the unglamorous plumbing the whole module depends on. Runs 100% locally on any OS.