Days 1–30: assess and plan

Inventory workloads, classify by criticality, run AWS Migration Evaluator. Pick the 6 Rs strategy per workload: rehost, replatform, refactor, repurchase, retire, retain.

Days 31–60: migrate non-critical workloads

Start with dev/test, internal tools and stateless web apps. Use AWS Application Migration Service for lift-and-shift; containerize what's already 12-factor.

Days 61–90: cut over production + optimize

Blue-green production cutover, enable Cost Explorer + Savings Plans, set CloudWatch alarms. Expect 18–35% infra cost reduction after the first quarter of right-sizing.