10. Phases of a Successful Migration
2024-09-01
Every migration to AWS goes through a set of distinct phases. But most failures happen not from skipping phases — but from not treating them seriously enough.
Here is a real-world take on the eight stages you need to manage:
Monitoring: Instrument your system before interviewing anyone.
Multiple perspectives: Ask different roles to describe the same stack — compare their answers.
Dependency mapping: Databases, cron jobs, third-party APIs, hardcoded credentials, shared file systems.
Risks and unknowns: Surface what might break even before you plan the first step.
Don't trust anyone's memory alone. Confirm everything with logs, metrics, and oppositional interviews.
Plan around product cycles and seasonality.
Include developers, not just DevOps.
Define responsibilities clearly: who owns what?
Create a map of each layer (network, storage, compute) for old vs. new.
Include downtime windows if needed, and know your rollback points.
Most failed plans come from planning in isolation or ignoring the business calendar.
This is the setup phase — and often rushed. But your tools, roles, and visibility need to be ready before migrating anything.
CI/CD ready for cloud environment
IAM roles and permissions created
Logging, metrics, and dashboards prepared
Load testing tools + scenarios built and validated
Plan for test execution (not just writing tests)
Whitelist IPs, register staging environments with external systems
Warm up email and traffic infrastructure if needed
Also, prepare team communication protocols. Who does what during testing, rollout, rollback?
Application behavior changes with more resources
Graceful shutdown and autoscaling create issues in legacy apps
Liveness/readiness probes introduce new failure modes
Network throughput behaves differently
This phase isn’t just technical. It’s psychological. If teams see instability, they may resist. Have fast triage paths and confident observability to reduce fear.
Just because it’s live doesn’t mean it’s done.
Monitor scaling behavior and resolve edge cases
Add any missing metrics, dashboards, or logs
Enable support and BI to respond to new alert patterns
Watch adoption: Are people routing around the new infra?
If the team doesn’t adopt it, they will start undermining it. Monitor people, not just servers.
AWS won’t save you money unless you make it.
Right-sizing instances
Moving background workloads to spot instances
Replacing temporary migration hacks
Tuning queues, caches, and storage performance
This is where you transform AWS from "expensive hosting" into "scalable platform."
No migration is finished until the team is working confidently in the new world.
Developers and DevOps
Support and incident responders
QA and test engineers
BI, analysts, and data consumers
Product managers and delivery leads
External or contract contributors
Change won’t stick if people keep falling back to what they know. Make training real, and tear down the old scripts and systems.
Daily/weekly cost reviews early on
Regular alert review and tuning
Environment drift checks for IaC
Periodic architecture reviews post-migration
Cleanup of unused resources
Retrospectives with affected teams
1:1 interviews for hidden pain points
This is the maturity phase. Your job now is to protect the win, extract the value, and prevent regression.
Migration doesn’t end when the system is live. It ends when the old system is gone, the new one is trusted, and the team can move faster than before.