Domain 4 · Migration and modernization
20% of the exam. Deciding what to move, how to move it, and what it should become on AWS.
The questions in this domain follow a migration from start to finish: assess the portfolio, choose a strategy for each workload, pick the transfer tools, then choose the target architecture and look for ways to modernize.
| Task | What it's really asking | Pages |
|---|---|---|
| 4.1 Select workloads | Discovery, portfolio assessment, the 7Rs, TCO | Assessment and the 7Rs |
| 4.2 Migration approach | Which tool moves the data, the servers and the databases | Data transfer, Server migration, Database migration, Hybrid connectivity |
| 4.3 New architecture | Target compute, containers, storage and database | Modernization, Compute and containers |
| 4.4 Modernization | Decoupling, serverless, purpose-built databases | Modernization, Decoupling, Purpose-built databases |
Exam signal
"Quickly", "with minimal changes" or "before the data center lease ends" point to rehost first and modernize later. "Reduce licensing costs" or "remove operational burden" point to replatform or refactor.
Cost optimization
Finding and removing waste in an existing AWS environment, from idle resources and NAT gateway charges to rightsizing before you commit.
Assessment and the 7 Rs
Picking a migration strategy per application, building the business case, discovering servers and dependencies, and planning waves.