Build a dependable inventory
Document applications, databases, storage, scheduled jobs, domains, certificates, identity providers, external APIs, network dependencies, data flows, owners, and current support expectations. Include manual processes that may not appear in architecture diagrams.
Record traffic patterns, resource utilization, data growth, availability needs, recovery objectives, licensing constraints, and sensitive-data classifications. These facts shape the target design and migration order.
Choose a migration path per workload
Rehosting, replatforming, refactoring, replacing, retaining, and retiring solve different problems. Do not force every workload into the same approach. A stable low-change service may move largely unchanged, while a fragile system might need staged modernization.
For each workload, document the proposed path, expected benefit, dependencies, rollback option, test approach, decision owner, and conditions that must be met before migration.
Establish the landing zone first
Set up account or subscription structure, identity, least-privilege access, network boundaries, encryption, key management, logging, budgets, tagging, policy enforcement, and environment separation before moving production data.
Use version-controlled infrastructure and repeatable deployment pipelines where practical. Repeatability makes reviews, recovery, and later environments more reliable than manual configuration.
Design observability and recovery
Define service indicators, dashboards, actionable alerts, log retention, audit trails, backup schedules, and escalation ownership. Monitoring added after migration often misses the signals teams need during the riskiest period.
Test restoration rather than assuming backups work. Confirm recovery time and recovery point expectations with business owners, and document what happens when a dependency or region becomes unavailable.
Migrate in controlled waves
Begin with a representative but lower-risk workload, validate the process, and update the runbook before larger waves. Each wave should have readiness checks, a change window, communications, validation steps, rollback criteria, and an accountable decision maker.
After each move, compare reliability, performance, security posture, and cost with the baseline. Decommission old resources only after data retention, rollback, and stakeholder requirements are satisfied.