Most checklists could apply to any provider, any workload, any business. This one is built specifically around moving to AWS, and around the question CTOs and IT directors actually care about: how do you migrate without disrupting the business that depends on the systems you're moving.
AWS's own current migration guidance separates the work into three phases: assess, mobilize, and migrate. This checklist follows that same structure, since it reflects how migrations actually succeed or fail in practice, not a marketing framework.
The Checklist
Five phases, in the order that actually works
Assess & Build Readiness
Get an honest picture of what you're moving
Application inventory.
List every application, service, and dependency currently running. This sounds obvious and gets skipped constantly. It's the single most common reason migrations run over schedule.
Application dependency mapping.
Understand what talks to what. An application that looks simple to move can be tangled with three other systems that weren't on anyone's radar until cutover day.
Cloud readiness assessment.
Evaluate which workloads are genuinely ready to move as-is, which need changes first, and which shouldn't move at all yet. An AWS migration readiness assessment earns its cost here, catching expensive surprises before they become live incidents.
Build the business case.
Cost, expected downtime, risk, and timeline all belong in a written business case before migration begins, not worked out informally as you go.
Strategy & Foundation
Choose your migration strategy and build the foundation
Pick the right strategy per workload,
not one strategy for everything. See the strategy breakdown below.
Build your AWS landing zone.
Your account structure, network architecture, and baseline security setup, the foundation everything else gets built on. Getting this wrong early is expensive to fix later.
Set up security and IAM before you migrate, not after.
Identity and access management, encryption standards, and compliance requirements need to be part of the foundation, not a retrofit.
Pilot, Test & Prepare
Pilot, test, and prepare for cutover
Run a pilot migration first.
Move a low-risk, low-visibility workload before touching anything business-critical. This is where you find the problems your planning missed.
Plan migration waves.
Group applications by dependency, risk, and business priority rather than migrating everything at once. Waves are what make "without business disruption" achievable in practice, not a promise.
Test before cutover, not during it.
Performance and user acceptance testing need to happen against the migrated environment before it goes live.
Have a rollback plan for every wave.
If something goes wrong mid-migration, you need a defined way back, not an improvised one. Not optional for anything customer-facing.
Migrate & Cut Over
Migrate and cut over
Synchronize data before cutover.
Data replication needs to be running and verified well before the actual cutover window, not started the night before.
Define your cutover window and communicate it.
A clear, communicated window means the business knows exactly what to expect and when.
Monitor actively during and immediately after cutover.
This is when problems surface, if they're going to. Active monitoring catches issues before they become customer-facing incidents.
Validate & Optimize
Validate and optimize
Validate against your RPO and RTO targets.
Parse these from phase one and confirm the migrated environment actually meets them.
Right-size and optimize costs after migration, not during it.
Migrating first and optimizing second is usually the more reliable order.
Keep the rollback and disaster recovery plan current.
A migration isn't finished when the last workload lands. Ongoing business continuity planning is part of the job going forward.
Next Steps
Not sure which wave your workloads belong in?
A readiness assessment tells you what's safe to move first, what needs work, and what shouldn't move at all yet.
Phase 2, In Detail
Match the strategy to the workload, not the other way around
AWS's current guidance discusses rehost, replatform, refactor, and repurchase as the main strategies. Different applications in your portfolio will call for different ones.
Moves an application as-is. Fastest, lowest effort. Right when you need speed or the app doesn't need architectural change.
Makes minor optimizations during the move, like shifting a self-managed database to a managed AWS service. Modest effort, meaningful operational benefit.
Re-architects the application for cloud-native services. Highest effort, but the right call when an application needs significant work anyway or has real scaling limitations.
Replaces the application with a SaaS equivalent instead of migrating it at all.
Some applications should simply be retired. It's common to discover a meaningful share of an application portfolio isn't worth migrating in the first place.
A Note on Business Continuity
Be honest about "zero downtime"
Whether a migration can achieve genuinely minimal downtime depends heavily on the workload's architecture and the migration method chosen. A stateless, well-architected application can often move with very little disruption. A tightly coupled legacy system with a large database usually can't, no matter how well the migration is planned.
The honest goal for most businesses isn't zero downtime. It's minimizing downtime through waves, testing, and a real rollback plan, and being transparent about which workloads carry more risk than others.
A Note on AWS Migration Tools
Worth knowing, without turning this into a product catalog
Your AWS landing zone setup typically also draws on the AWS Well-Architected Framework as a baseline for security, reliability, and cost practices.
What This Actually Costs
AWS migration cost varies enormously based on portfolio size and how many applications need refactoring versus a straight rehost. A cloud migration business case should account for both the one-time migration cost and the ongoing total cost of ownership afterward. A migration that moves everything but doesn't right-size afterward can quietly cost more than the on-premises setup it replaced.
Seaflux's Approach
Built around assess, mobilize, migrate, not a one-size-fits-all playbook
As an AWS Select Consulting Partner, our cloud migration consulting covers readiness assessment, landing zone design, infrastructure as code consulting using Terraform, and migration execution designed to minimize disruption to the business systems that depend on what's being moved.
We've applied this directly to real, regulated environments:
Retail & eCommerce
AWS cloud migration for a luxury retail brand
Used Terraform infrastructure as code and automated deployment to solve security and scalability problems in an on-prem setup that couldn't handle traffic bursts.
View case study
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Healthcare · HIPAA
HIPAA-compliant AWS cloud migration
Moved infrastructure to AWS with zero-trust security and Terraform-based infrastructure modernization, a case where business continuity wasn't optional.
View case study
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Our full cloud migration services page covers assessment, deployment, and cutover in more depth, alongside our broader cloud computing services for teams also weighing DevOps, cost management, and cloud-native application development as part of the same project.
Ready to plan your AWS migration without the disruption?
Start with a readiness assessment and a wave plan built around your actual dependencies, not a generic template.
