INSIDE MICROSOFT'S FRONTIER PRE-TRAINING STACK

Summary from the TLDR AI newsletter

Microsoft detailed the training of MAI-Base-2, a 2.8T-parameter mixture-of-experts model with 80B active parameters that it said surpassed every open-weight model in its held-out pre-training evaluations. The deep dive covers its data strategy, compute efficiency, full-stack infrastructure, and Microsoft's plans to turn internally trained frontier models into enterprise offerings through Foundry.