A Modern Data Stack project starts with a data audit: what data exists, where it is stored, its quality, who is accountable for it, and which business processes rely on it. On this basis we prepare a migration map, MVP scope and priority data domains. The first warehouse or lakehouse for a single domain - for example sales, finance or operations - is typically launched in 10-14 weeks. We then extend the solution to further data domains, developing governance, data-quality monitoring, lineage and a data-ownership model in parallel. A full migration from an on-premise warehouse to a modern data stack usually takes 12-24 months and is carried out in stages, with a dual-run period for source systems and the new data platform.