Replatform, Refactor, or Rehost? Choosing the Right AWS Migration Strategy

AWS migration fundamentally transforms businesses, not just IT Systems. Companies that adopt the right AWS cloud migration strategy scale their systems, optimize operations, cut expenses, and prepare infrastructure for the long term. This journey begins by selecting the right migration path — rehost, replatform, or refactor. Each choice has unique benefits and challenges that determine when each approach is most suitable. The differences you identify help companies achieve immediate results and ensure future-ready growth.

Key Takeaways

• Rehost: Fastest and simplest method for quick migration.
• Replatform: Targeted optimizations are possible without complete redevelopment.
• Refactor: Full cloud-native advantages, but requires more time and resource investment.
• Hybrid Migration Plan: This approach usually works best for complex enterprises.
• Best Practices: Adopting AWS recommended migration practices minimizes risk and maximizes ROI.

What is AWS Cloud Migration?

AWS Cloud migration means moving your apps, databases, and workloads from the current infrastructure or existing cloud to AWS so that you can reap the full benefits of the cloud. Your cloud migration strategy determines whether workloads should be lifted and shifted incrementally improved, or fully rebuilt for the cloud.

Choosing the right AWS cloud migration strategy is about balancing:

• Speed – How quickly you need to move.
• Cost – The budget available for migration.
• Performance – The desired improvements in scalability and efficiency.
• Risk tolerance – The acceptable level of downtime and operational change.

Why Cloud Migration Matters

Migrating to AWS can completely transform your business operations. This isn’t just an IT decision—understanding it is crucial for every business:

Scalability

AWS’s elastic scaling feature allows you to adjust your workloads according to demand, whether there is a traffic spike or your business is growing rapidly, without spending on unnecessary hardware.

Cost Savings

AWS’s pay-as-you-go model charges you only for the resources used, while also saving the cost of maintaining physical hardware.

Security & Compliance

AWS has top-notch security certifications and compliance standards, including HIPAA and SOC 2, to keep your workloads safe and compliant.

Performance Optimization

With a global infrastructure and strategically placed edge locations, the speed and availability of applications is optimized for users everywhere.

Managed Services

To reduce operational complexity, take advantage of AWS’s managed solutions—whether it’s databases, analytics, or machine learning, everything is managed effortlessly.

Overview of AWS Migration Strategies

AWS outlines several migration approaches, but for most businesses, three dominate: rehost, replatform, and refactor.

Rehost (Lift and Shift)

Move applications to AWS with little to no modification.

How it works: Use AWS services like Migration Hub and Server Migration Service to replicate workloads directly into AWS.

Pros:

• Fastest migration path
• Lower upfront cost
• Minimal disruption to existing workflows

Cons:

• Doesn’t leverage AWS-native capabilities
• May carry over performance bottlenecks

Best Use Cases:

• Urgent data center lease expirations
• Legacy apps you plan to modernize later
• Proof-of-concept migrations to AWS

Example: A retail chain moves its ERP system to Amazon EC2 without changing its architecture to meet a tight migration deadline.

Replatform (Lift, Tinker, and Shift)

In this approach, some selective optimizations are done while migrating applications without changing the core architecture.

How it works: Some critical parts, like databases and storage, are migrated to AWS-managed solutions — using Amazon RDS and S3 — so you gain cloud benefits without requiring major code modifications.

 Pros:

• Improves performance and maintainability
• Introduces AWS-native tools without full rebuild

 Cons: 

• More planning and testing than rehost
• May require short downtime windows

Best Use Cases: 

• Applications needing better scalability or maintainability
• Workloads benefiting from managed services

Refactor (Re-architecting)

Apps are rebuilt to fully leverage the AWS cloud-native features and boost both system performance and scalability.

How it works: Splitting monolithic applications into microservices, adopting serverless functions like AWS Lambda, and containerizing workloads using AWS ECS or EKS to improve scalability, portability and operational efficiency.

 Pros:

• Maximizes agility and cost efficiency
• Supports rapid innovation and scaling

 Cons:

• Highest cost and complexity
• Longer migration timelines

 Best Use Cases: 

• Companies that want to upgrade and modernize old applications
• Organizations with long-term plans for cloud adoption
• Workloads where performance and scalability are becoming limited

Example: A fintech company converts its core platform to microservices architecture, ensuring global scalability by adopting AWS Lambda and Amazon DynamoDB.

How to Choose the Right Strategy

The ideal AWS migration strategy depends on: 

Business priorities: Speed vs. optimization vs. modernization. 

Application Complexity: Some applications can be shifted directly to the cloud, while redesign is necessary for complex workloads. 

Budget: Rehosting is right if short-term cost reduction is needed, but refactoring is better for long-term ROI. 

Compliance & Risk: In certain industries, it is required to follow a phased or hybrid migration.

Example: In a phased migration, simple workloads are rehosted first, and then selected workloads are replatformed or refactored and migrated — both short-term results and long-term benefits are achieved.

AWS Cloud Migration Best Practices

No matter which migration path, following these best practices increases the chance of success: 

• Comprehensive Assessment: Thoroughly check every workload and its dependencies, supported by cloud migration strategy consulting, ensure that compliance standards are maintained and migration risks are prioritized.
• Use of AWS Well-Architected Framework: Adopt the framework and create a secure and budget-friendly cloud setup.
• Automate Deployments: Implement automation via CloudFormation or Elastic Beanstalk and minimize errors.
• Security Setup: Set up IAM roles, apply data encryption, and protect sensitive information in separate network segments.
• Monitor Performance: Post-migration, track performance via CloudWatch and X-Ray and efficiently optimize workloads.

Conclusion

Choosing to rehost, replatform, or refactor in an AWS migration is not just an IT matter but it shapes your long-term business goals and operational strategy.

• Rehost offers speed and simplicity.
• Replatform balances optimization with cost.
• Refactor to future-proof your infrastructure for innovation.

AllCode’s AWS cloud migration services are specially designed to ensure smooth migration, keep costs under control, and make scalability easy. From fast migration to modernization, we ensure that your AWS cloud migration strategy is efficient and impactful at every step. 

Explore our AWS Cloud Migration Services or contact us today to start migrating to AWS with confidence.

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