M5 is a multi-year initiative to build and productize large-scale foundation model on massive World and Amazon data for use by teams across SDO to improve Amazon customer experience. We build large scale foundation models for both generative and representational tasks using cutting edge techniques, and publish papers to internal and external top conferences to contribute broader science community. In the past four years, M5 has enabled over 100 production launches across SDO which generated $+4B OPS and $+4B GCCP measured via weblabs, and published 40+ papers in external top conferences in NLP/CV/ML areas.