AWS Migration Best Practices
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Moving applications, databases, and infrastructure to AWS can unlock greater scalability, flexibility, resilience, and cost control. But a successful cloud migration is not simply a matter of copying virtual machines from an on-premises environment or another cloud platform into AWS.
Migration is a business and technical transformation. Mission-critical applications may have complex dependencies, legacy systems can behave differently in the cloud, and a poorly planned cutover can create downtime, data loss, unexpected infrastructure costs, or security gaps.
The best AWS migrations therefore start long before the actual migration. They connect business objectives to technical decisions, establish the AWS environment correctly, assess dependencies, select the right migration strategy for each workload, and move applications in controlled waves.
At Cloudvisor, we approach AWS migration as a structured journey from discovery and planning through replication, testing, cutover, and post-migration optimization. We plan migration waves, test workloads, synchronize data, and schedule cutovers to reduce disruption.
What makes an AWS migration successful?
A successful AWS migration moves the required workloads without losing sight of why they are moving in the first place. Speed matters, but so do application availability, security posture, cost efficiency, operational readiness, and the ability to take full advantage of AWS services after migration.
AWS structures large migration programs around assess, mobilize, and migrate phases. The early stages establish the business case, migration readiness, governance, operating model, AWS foundation, and migration plan before workloads move at scale.
1. Define clear migration goals and the business case
One of the most important AWS migration best practices is to define clear migration goals before selecting tools or moving workloads. Cloud migration should support a business strategy, not exist as a technical project with no measurable outcome.
Start by asking what the migration needs to achieve. Common goals include reducing infrastructure costs, exiting a data center, improving scalability, strengthening resilience, accelerating deployment, reducing operational overhead, or creating a foundation for application modernization.
Translate these goals into measurable KPIs. Depending on the project, success metrics could include target infrastructure savings, availability, deployment frequency, latency, recovery objectives, migration completion dates, or the percentage of legacy applications retired or modernized.
Calculate costs before making migration decisions
Cloud costs work differently from traditional on-premises infrastructure. Before migrating, compare the current cost base with expected AWS usage, migration effort, licensing, connectivity, support, and the cost of running source and target environments in parallel during transition.
AWS Migration Evaluator can help organizations build a data-driven business case, identify over-provisioned on-premises instances, compare AWS scenarios, and evaluate licensing options before making migration decisions. (Amazon Web Services, Inc.)
Using actual utilization data at this stage helps avoid simply reproducing oversized infrastructure in the AWS Cloud and creates a more realistic baseline for expected cost savings.
2. Assess your current infrastructure and application dependencies
A comprehensive assessment of the current infrastructure is a critical step in any cloud migration strategy. Build an inventory of applications, servers, databases, storage, network connections, operating systems, licenses, users, owners, and business criticality.
Then document application dependencies. A web application may depend on a database, identity provider, file share, third-party API, scheduled task, internal DNS service, or another legacy application that is not obvious from the infrastructure diagram.
Dependency mapping reduces the risk of moving one component while leaving something essential behind. It also helps determine which applications should move together in the same migration wave and which workloads can be migrated independently.
AWS recommends portfolio assessment as part of migration planning, including discovery and analysis of applications and the underlying compute, storage, and network infrastructure. (AWS Documentation)
Use a Migration Readiness Assessment and AWS CAF
AWS defines a Migration Readiness Assessment, or MRA, as a way to understand an organization’s cloud readiness, identify strengths and weaknesses, and create an action plan for gaps that could block migration.
The assessment can use the AWS Cloud Adoption Framework across six perspectives: business, people, governance, platform, security, and operations. This helps evaluate migration as an organizational transformation rather than only a technical infrastructure project.
3. Choose the right migration strategy for each workload
There is no single migration strategy that is right for every application. AWS currently defines seven common migration strategies, known as the 7 Rs: retire, retain, rehost, relocate, repurchase, replatform, and refactor or re-architect.
For large migrations, it is often better to avoid unnecessary transformation during the move. AWS Prescriptive Guidance identifies rehost, replatform, relocate, and retire as common approaches for large migrations and notes that extensive refactoring can significantly increase complexity.
Rehost, replatform, or refactor?
Rehost, commonly called lift and shift, moves an application into AWS with minimal changes. It can be useful when a company needs to exit a data center quickly, migrate a large number of servers, or postpone application modernization until after migration.
Replatform makes targeted changes to benefit from cloud services without rebuilding the whole application. Moving a self-managed database to Amazon RDS is a common example. This can reduce infrastructure management while keeping application changes manageable.
Refactor or re-architect changes the application more substantially to take advantage of cloud-native architecture. It can deliver greater long-term benefits, but it usually requires more engineering work, testing, and coordination.
The best migration methodology can combine these patterns. A legacy application may be rehosted first to meet a deadline and modernized later, while another workload may be replatformed during migration because the change is low risk and removes significant operational burden.
4. Build the AWS foundation before workloads arrive
Security and governance should not be added after the migration. Before moving production workloads, establish the foundational AWS environment where applications will run.
AWS describes a landing zone as the baseline for multi-account architecture, identity and access management, governance, data security, network design, and logging. AWS Control Tower is one option for establishing and governing this type of multi-account AWS environment.
Establishing these core components early prevents teams from creating inconsistent AWS accounts and configurations during migration and then having to retrofit governance later.
Design identity, networking, encryption, and logging from day one
Identity and Access Management is central to the AWS security model. Define who can access the AWS environment, use role-based permissions, apply least privilege, and avoid giving internal users broader permissions than their work requires. AWS identifies least-privilege permissions as an AWS Well-Architected security best practice.
Plan the network architecture before cutover. Amazon Virtual Private Cloud, or Amazon VPC, can provide logically isolated networking for AWS resources. Subnet design, routing, DNS, connectivity to on-premises systems, security groups, and traffic flows should be understood before applications depend on them.
Encryption requirements should also be established for data at rest and in transit, with appropriate key-management practices. Compliance requirements, industry regulations, and data residency constraints should influence architecture before sensitive data is moved. AWS recommends encryption alongside identity, resource, and network access controls.
Logging and configuration visibility are equally important. AWS CloudTrail provides activity records for auditing and governance, while AWS Config provides configuration history and can evaluate resources against compliance rules.
5. Plan migration waves instead of moving everything at once
A phased approach reduces operational risk. Rather than treating the migration as one large cutover, group applications into migration waves based on dependencies, business criticality, complexity, team availability, and required cutover windows.
Start with workloads that can validate the migration process without putting the most critical systems at unnecessary risk. Early waves help test landing-zone assumptions, networking, permissions, migration tooling, documentation, and operational handoffs.
AWS migration tooling also supports grouping servers into applications and applications into waves, allowing migration activity to be coordinated across larger environments.
Run a pilot migration before scaling
A pilot is more than a technical demonstration. It should test the end-to-end migration process: replication, launch, application validation, monitoring, user access, operational procedures, cutover, and rollback.
The results from the pilot can then be used to improve procedures before larger migration waves begin.
6. Select AWS migration tools based on the workload
AWS provides numerous tools for moving servers, databases, and files. The best tool depends on what is being migrated, how much downtime is acceptable, how much data must move, available bandwidth, and whether the source is on premises, another cloud, or a hosted platform.
We select migration tooling based on your stack and risk tolerance.
AWS Transform MGN (formerly AWS Application Migration Service)
AWS Transform MGN, formerly AWS Application Migration Service, automates the migration of physical, virtual, and cloud servers to AWS using continuous block-level replication.
We use MGN for lift-and-shift scenarios where speed and minimal refactoring are priorities, continuously replicating workloads, testing them in AWS, and cutting over when the target environment is ready. Our current Migration service follows this same approach for Windows and Linux server migrations.
Use AWS Database Migration Service for database replication
AWS Database Migration Service, or AWS DMS, supports database migrations and ongoing replication. Change data capture keeps source changes replicating after the initial load, helping reduce downtime during final cutover. (AWS Documentation)
AWS DMS supports both homogeneous and heterogeneous database migrations across supported engines. For example, a database may move to an equivalent engine on Amazon RDS, or a migration can involve changing database platforms when compatibility and schema conversion are addressed.
Database migration requires validation beyond simply seeing a replication task complete. We run test loads, validate data, monitor replication, and coordinate final database cutovers during low-traffic windows where possible.
Track progress and move files with the right AWS services
AWS Transform is AWS’s current migration and modernization service for new migration projects. It brings together capabilities for discovery, migration planning, workload grouping, and migration execution with AI-assisted automation.
For large file transfers, AWS DataSync can move data between on-premises storage and services such as Amazon S3, EFS, and FSx. Physical AWS transfer options can also help when bandwidth makes online transfer impractical.
7. Test every migration wave before production cutover
Testing is one of the simplest ways to reduce migration risk, yet it is often compressed when timelines get tight. Every migration wave should have clear technical and business validation criteria before production traffic is moved.
Test application functionality, performance, integrations, identity, permissions, network connectivity, backups, monitoring, logging, security controls, and expected user journeys. For business-critical applications, involve application owners and internal users who understand normal system behavior.
Document acceptance criteria before testing begins. This makes go/no-go migration decisions clearer and reduces pressure to approve a cutover based on incomplete checks.
Coordinate the cutover window and rollback plan
A cutover plan should define the sequence of actions, owners, communication channels, validation steps, expected duration, rollback criteria, and the point after which rollback becomes difficult or unsafe.
Coordinate cutover windows with business teams and schedule them during lower-traffic periods where practical. For data-intensive migrations, monitor replication lag and complete the final synchronization before directing users or traffic to the AWS environment.
At Cloudvisor, we use continuous replication, testing, and planned low-traffic cutovers to help minimize interruption during the actual migration.
A rollback plan is not a sign that the migration is expected to fail. It is part of careful planning for systems where downtime or data loss would carry meaningful business risk.
8. Prepare people and operating processes for AWS
AWS migration introduces new services, responsibilities, and operational practices. Training staff early makes the transition smoother and reduces the risk that a technically successful migration leaves teams unable to operate the environment confidently.
Update architecture diagrams, runbooks, access procedures, incident-response processes, backup documentation, recovery instructions, and ownership information as the AWS environment is built. Documentation created before migration should be updated to reflect the actual production architecture.
Plan a structured handover for the teams that will manage the environment after migration. In our HelloSafe migration, for example, the project concluded with architecture documentation, best-practice guidance, and a knowledge-transfer session so the client’s team could confidently manage its AWS setup.
9. Monitor and optimize after the actual migration
Production cutover is not the end of the cloud migration process. The first weeks after migration provide real workload data that should be compared with the assumptions made during assessment and planning.
Use monitoring to track application performance, availability, resource utilization, errors, and operational health. Amazon CloudWatch focuses on monitoring and operational health, while AWS CloudTrail provides visibility into activity for auditing, security, and governance.
Post-migration optimization can include rightsizing instances, introducing Auto Scaling, adjusting storage, tuning databases, removing temporary migration infrastructure, improving resilience, or modernizing workloads that were initially rehosted.
The goal is to move beyond simply running the same infrastructure in another location and start using AWS cloud capabilities where they create measurable business value.
Add FinOps and cost optimization to day-two operations
Cloud services make infrastructure easy to provision, which also makes cost governance important. Establish ownership, budgets, tagging, cost visibility, and regular optimization as ongoing operating practices.
A successful migration should not reproduce on-premises overprovisioning in the cloud. At Cloudvisor, we optimize AWS setups for long-term cost efficiency after migration and can continue supporting customers through AWS cost optimization, Well-Architected reviews, and managed AWS services.
Common AWS migration pitfalls to avoid
The first common pitfall is migrating before understanding dependencies. An incomplete inventory can lead to broken integrations, inaccessible services, and emergency work during a cutover window.
The second is treating lift and shift as the final architecture by default. Rehosting can be the correct migration decision, but legacy applications moved unchanged may not automatically gain the full operational or cost advantages available from cloud services.
The third is delaying security and governance. Building identity, logging, network controls, compliance, and account structures after workloads arrive creates unnecessary rework and can weaken the security posture during migration.
Another pitfall is migrating without measurable goals. If a team cannot define what success looks like, it becomes difficult to determine whether AWS cloud migration delivered true value or simply changed the location of the infrastructure.
Finally, avoid treating migration as an infrastructure-only project. Application teams, security, finance, operations, and business owners all influence migration decisions and need to understand their responsibilities before cutover.
Why work with an experienced AWS migration partner?
Cloud migration requires expertise across infrastructure, applications, databases, networking, security, governance, and cost management. An experienced AWS partner can fill capability gaps and reduce the learning curve.
We are an AWS Advanced Tier Partner with 50+ AWS certifications, and our migration service covers the journey from discovery to cutover and post-migration optimization. We assess the current environment, define the migration strategy, select tools based on the workload, plan waves, test, synchronize data, and coordinate cutover.
Our migration options include MGN for server migrations, AWS DMS for databases, AWS DataSync for file transfers, and modernization approaches for more complex legacy or mainframe applications. We also help eligible customers identify AWS funding opportunities for migration projects.
Our migration case studies show how a structured approach works in practice. For HelloSafe, we migrated services from Heroku to AWS in four phases covering AWS account setup, infrastructure as code, staging, CI/CD, verification, production deployment, and knowledge transfer.
Following the migration, HelloSafe achieved 30% lower monthly cloud spend and 99.99% uptime, while the migration itself was fully covered by AWS funding.
We have also migrated G-Works from an on-premises environment to AWS, using a container-based architecture with Amazon ECS, AWS Fargate, and Auto Scaling to create a more maintainable and scalable environment.
If you are planning an AWS migration, we can start with a free migration assessment. Our AWS Solutions Architect reviews your current environment, outlines an appropriate migration strategy, and provides a no-commitment Statement of Work.
Talk to our AWS migration experts and build a migration plan designed around your workloads, business objectives, and risk requirements.
Frequently asked questions
1) What are the most important AWS migration best practices?
Start by defining clear migration goals, assessing your current infrastructure and dependencies, choosing the right migration strategy for each workload, and establishing security and governance before production systems move.
Use a phased approach, test each migration wave, maintain a rollback plan, monitor data replication, and validate applications before cutover. After migration, continue monitoring, rightsizing, cost optimization, and application modernization where it creates business value.
2) What are the AWS migration strategies?
AWS currently defines seven migration strategies, or 7 Rs: retire, retain, rehost, relocate, repurchase, replatform, and refactor or re-architect.
Lift and shift is another name for rehosting. It is often used when speed is important and major application changes can wait, while replatforming and refactoring introduce progressively more change to take advantage of cloud services.
3) What is AWS Transform used for?
AWS Transform is AWS’s current migration and modernization service for new migration projects. It brings together capabilities for discovery, migration planning, workload grouping, and migration execution with AI-assisted automation.
AWS Migration Hub previously provided centralized migration planning and tracking and remains available to existing customers. However, AWS stopped accepting new Migration Hub customers in November 2025 and now recommends AWS Transform for new migration projects.
4) How can AWS DMS reduce database migration downtime?
AWS Database Migration Service can perform an initial data load and then use ongoing replication, or change data capture, to replicate subsequent changes from the source database.
This allows the source to continue operating while the target stays synchronized. The final cutover can then be coordinated after replication lag and data validation meet the project’s acceptance criteria.
5) Should we use lift and shift or modernize during migration?
It depends on business objectives, timelines, technical debt, and the specific workload. Lift and shift can expedite migration and data center exit, but it may carry existing inefficiencies into AWS.
For some applications, replatforming during migration can provide clear value without creating excessive risk. Larger refactoring projects are often easier to manage after workloads have been migrated and stabilized, particularly during large migration programs. AWS Prescriptive Guidance similarly cautions against making extensive refactoring part of a large migration unless there is a strong reason to do so.
6) How do we reduce security risks during an AWS cloud migration?
Establish the AWS foundation before moving production workloads. This includes account structure, identity and access management, least-privilege permissions, Amazon VPC network design, encryption, logging, monitoring, backup, and governance controls.
AWS Config can provide configuration and compliance visibility, AWS CloudTrail can support auditing and governance, and Amazon CloudWatch can monitor operational health. Involve security and compliance teams during migration planning rather than waiting for production cutover.
7) What is a migration wave in AWS?
A migration wave is a group of applications or servers planned to move within the same stage of a larger migration. Grouping workloads into waves helps teams coordinate dependencies, testing, resources, and cutover windows.
AWS Transform MGN supports organizing servers into applications and applications into waves, which can help teams manage migrations at scale.
8) How can AWS Migration Evaluator help with migration planning?
AWS Migration Evaluator helps organizations assess their current infrastructure and build a data-driven business case for AWS migration. It can provide insights into existing utilization, infrastructure requirements, licensing, and potential AWS costs.
Using tools like AWS Migration Evaluator during the assessment stage can help identify overprovisioned resources, estimate potential cost savings, and support better migration decisions before workloads are moved.
9) How should business and IT teams align before an AWS migration?
A successful cloud migration should start with a clear vision shared by both IT and business stakeholders. Technical migration goals should connect directly to business objectives such as reducing infrastructure costs, improving scalability, increasing resilience, accelerating development, or exiting a data center.
Establishing this alignment early helps teams prioritize the right workloads, define meaningful KPIs, and avoid migration decisions that add technical effort without creating measurable business value.
10) How can organizations maintain compliance during an AWS migration?
Security, governance, and compliance requirements should be established before production workloads are migrated. In addition to defining access policies, encryption, logging, and network controls, organizations can establish automated standards for compliance tracking early in the migration process.
AWS services such as AWS Config can continuously evaluate resource configurations against defined rules, helping teams identify configuration changes and potential compliance issues as the AWS environment grows.
11) Why is staff training important during an AWS migration?
AWS migration often introduces new services, security models, operational processes, and responsibilities. Training staff early helps smooth the AWS transition and prepares internal teams to operate the new cloud environment confidently after migration.
Training should be supported by updated architecture documentation, operational runbooks, access procedures, and knowledge-transfer sessions. This can reduce dependency on external support and improve long-term operational readiness.
12) How can Cloudvisor help with an AWS migration?
We manage AWS migrations from assessment and planning through hands-on migration, testing, cutover, and post-migration optimization. Our AWS Solutions Architects select migration patterns and AWS services based on the existing environment, dependencies, downtime requirements, risk tolerance, and business objectives.
We also help eligible businesses explore AWS migration funding opportunities. If you are considering migrating from on premises, another cloud platform, or an existing hosting provider, contact our team for a free migration assessment and a migration strategy tailored to your environment.
Sources: AWS Documentation
