AWS Application Modernization: Proven Strategies and Best Practices

When your application struggles to meet increasing business demands, seeking the most effective modernization approach becomes essential. However, considering AWS application modernization as a solution for your challenges raises several crucial questions:

• Is AWS application modernization the suitable approach to achieving your business goals?
• What are the challenges associated with AWS application modernization?
• What best practices of AWS modernization can improve overall outcomes?

This article aims to provide answers to these questions and help you confidently move forward in transforming your legacy system, scaling your application, and choosing the suitable cloud provider for your project. With more than 10 years of experience in building and modernizing software, I will share practical insights on AWS application modernization from our team and a real-world example of a successful modernization project.

Why modernize applications in AWS?

Cloud application modernization can be conducted in various ways, with AWS application modernization as its part. AWS application modernization is the process of updating and transforming existing applications to leverage the benefits of cloud computing on Amazon Web Services (AWS). This involves migrating, rearchitecting, and optimizing applications to improve performance, scalability, security, and cost-efficiency. 

AWS provides various services and tools to enable this transformation, offering a wide array of benefits. Here are some of them. 

1. Cost-effectiveness (reduced TCO)

AWS offers features for application modernization that reduce infrastructure, development, and deployment costs. The pay-per-use model can considerably lower the total cost of ownership (TCO) as you only pay for the instances that run, stopping them when they’re no longer needed.

2. Enhanced observability

Modernization projects can be challenging as they require a high level of observability to boost system resilience. AWS provides deep visibility into applications, customer journeys, and business outcomes. Key observability information includes:

• End-user experience
• Application performance
• Legacy application dependencies
• Resource usage
• Existing component bottlenecks

Observability relies on three key pillars: metrics, logs, and traces. AWS offers robust observability tools like Amazon CloudWatch and AWS Distro for OpenTelemetry (ADOT) to collect distributed traces and metrics for effective monitoring.

3. Reduced database dependencies

Legacy systems often have complex workloads that tightly rely on monoliths, making modernization challenging. Rewriting these applications for a cloud-native architecture can be labor-intensive, involving code refactoring, data models, test cases, and integrations. 

4. Enhanced security and compliance

AWS provides customizable and secure cloud computing environments that are compliant with cybersecurity best practices and standards. AWS employs layered controls, continuous validation and testing, and extensive automation to ensure that the underlying infrastructure is monitored and protected. Every new data center or service includes these security controls, meeting regulatory compliance regulations like GDPR and HIPAA. Built-in IAM tools help organizations efficiently implement security policies.

5. Higher performance

For business-critical operations, software applications should be able to handle high-intense workloads. AWS enables organizations to meet performance requirements, such as app response time and transactions per second by leveraging instant spot instances. This allows applications to handle growing user bases and efficiently manage fluctuating traffic.

6. Improved resilience and reliability

Resilience refers to an application’s fault tolerance, while reliability is its ability to meet expected performance and functionality standards. AWS enhances resilience and reliability through Well-Architected Framework Reviews (WAFR), which guide partners and customers in evaluating application architectures and implementing scalable designs.

The Well-Architected Framework includes best practices around six key aspects:

• Operational excellence
• Security
• Reliability
• Performance efficiency
• Cost optimization
• Sustainability

Additionally, AWS offers numerous tools and services to improve application resilience and reliability, ensuring that applications remain robust and effective in the face of challenges.

Common AWS application modernization use cases

While AWS application modernization can bring great benefits for the right use case, the decision of what to choose needs careful consideration. In the table below you will find some of the common cases of AWS app modernization.

Let’s take a more detailed look at these use cases. 

1. Lift and Shift (Migrate to Cloud) This involves migrating existing on-premises applications to the AWS Cloud with minimal changes to the application code or infrastructure. The main idea is to quickly move the application to the cloud to be able to use the capabilities of the cloud environment. 
2. Legacy modernization (Re-architecting legacy on-premises apps) This involves modernizing and re-architecting legacy on-premises applications and then moving to the cloud environment. This may include migrating to a managed database service, adopting containerization, or implementing serverless functions.
3. Refactor/Rearchitect (Modernize existing cloud app) In this approach, the existing cloud-based application is redesigned and refactored to take advantage of cloud-native services and best practices. This may involve breaking down a monolithic application into microservices, adopting serverless architectures, or using managed services like AWS EKS. 
4. Cloud to Cloud (Migrate Between Cloud Providers) This involves migrating an application from one cloud provider (e.g., Azure or Google Cloud) to AWS. This could be due to various reasons, such as cost optimization, better-suited services, or the need for a specific AWS feature.

3 key components of AWS modernization strategy

The main parts of the AWS modernization strategy include: assessing, modernizing, and managing stages. Let’s take a more detailed look at them.

1. Assess

Successful application modernization begins with a comprehensive analysis of the app portfolio. This involves selecting and evaluating the infrastructure to be modernized and designing a modernization plan based on a suitable strategy. To prepare for the assessment phase, it’s recommended that an application modernization questionnaire from AWS be used. This questionnaire helps analyze your current situation from various perspectives: business, people, management, security, and operations, and design the future state of architecture within a modernized infrastructure.

Key activities in the assessment phase include:

• App assessment considering business fit, functional requirements, technical requirements, financial fit, and digital readiness.
• App grouping, ranking, and sequencing
• Documenting target and interim operating models
• Understanding technology and regulatory requirements
• Determining apps needing extensive data migration
• Clarifying the scope of data to be converted

Outcomes of the assessment phase:

• Application modernization plan
• Technical and functional architecture for the desired state of an app, based on the analysis results

2. Modernize

The next phase is modernization. This involves establishing project objectives and resource requirements to create a detailed roadmap. This roadmap should align with the chosen strategy and result in an upgraded, reliable, and agile app architecture.

Key activities in the modernization phase include:

• Determining control points for transforming the app’s current code and data
• Analyzing functional requirements for running and managing the necessary infrastructure
• Implementing solutions that meet business and architecture requirements using cloud-based approaches and advanced technological solutions

According to AWS, the elements of a modernized application have these attributes:

• Packaged as lightweight containers
• Developed as loosely coupled microservices
• Consolidated around APIs for interaction and collaboration
• Designed with a clear separation of stateless and stateful services
• Separated from server and operating system dependencies
• Deployed on self-service, elastic, cloud infrastructure
• Operated via well-organized DevOps processes
• Included automated capabilities
• Delivered defined, policy-driven resource allocation 

Outcomes of the modernization phase:

• Target state data model design
• Organizational readiness
• Through procedures for change activities
• Optimized operating model and delivery effectiveness review
• Key business case metrics monitored for efficiency assessment 
• Planned upgrading and automation activities
• A clear roadmap with a modernization strategy for each application
• Modernization preparation and implementation

3. Manage

Post-modernization activities require maintaining and further upgrading modernized applications properly. Understanding the new app characteristics is essential. Adopting cloud-native features, such as microservice operations, means the development of a site reliability engineering (SRE) capability within the organization. The management phase involves change, program supervision, and quality assurance.

Key activities in the management phase include:

• Retraining staff on new app characteristics
• Forming an SRE capability for managing cloud-native features
• Supervising change programs
• Ensuring quality assurance

In the table below you can see the summary of the AWS application modernization process defined by stages. 

By following these structured phases — Assess, Modernize, and Manage, you can ensure a smooth and effective transition to modernized applications, leveraging the full benefits of cloud-native architecture and practices.

A step-by-step process of modernizing AWS applications

Managing a legacy application modernization journey is a significant assignment. It requires planning, execution, and an organization-wide readiness to embrace change. Let’s check how it might look step-by-step for successful application modernization on the AWS cloud.

Step 1. Assess your application portfolio

Analyze what applications you already have, and how they work, and identify which applications are qualified for modernization. Evaluate factors like technical debt, business value, and your business priorities to understand what aligns best with your organization’s strategic goals. Prioritize the applications based on their potential for improvement and business impact.

Step 2. Define your modernization goals

Determine the key drivers for software modernization, such as improving scalability, reducing costs, enhancing security, or increasing adaptability. Establish clear, measurable goals and success criteria for the modernization process so that the results can be evaluated later. Align the objectives with your organization’s overall technology and business strategies.

Step 3. Choose the right modernization approach

Evaluate different modernization strategies, such as rehosting, replatforming, or rearchitecting, based on your modernization goals and your application portfolio. Decide whether to migrate the application as-is, containerize it, or break it down into a microservices architecture. Consider leveraging AWS-managed services, serverless computing, or other cloud-native technologies to improve the application’s scalability and operational efficiency.

While choosing the right modernization approach can be challenging, our experienced software engineers and consultants can help you assess your needs and pick a tailored modernization strategy to achieve your business goals.

Step 4. Plan and prepare for the modernization

Conduct a detailed assessment of the application’s dependencies, data, and infrastructure requirements. Develop a comprehensive migration plan, including timelines, resource requirements, and risk mitigation strategies. Ensure that your team has the necessary skills and expertise to execute the modernization project. Set up the necessary AWS services, such as EC2, ECS, Lambda, or managed databases, to support the modernization process.

Step 5. Execute the modernization process

Gradually migrate the application to the cloud, following your defined modernization approach. Implement CI/CD pipelines and DevOps practices to streamline the deployment process. Continuously monitor the application’s performance, cost, and security to identify and address any issues. Ensure that the modernized application meets the defined objectives and success criteria.

Step 6. Optimize and maintain the modernized application

Continuously optimize the application’s architecture, infrastructure, and deployment pipeline to improve performance, cost-efficiency, and scalability. Leverage AWS services and tools, such as Amazon CloudWatch, AWS CloudTrail, and AWS Config to monitor and manage the modernized application. Adopt security measures, including identity and access management, data encryption, and vulnerability monitoring. Continuously review and update the modernization strategy to adapt to business and technological requirements.

AWS app modernization services that can help you

When it comes to modernizing applications, AWS offers a comprehensive suite of tools designed to streamline the process and ensure success. Here are some key tools that can assist you in your AWS application modernization journey.

Utilizing the right AWS services can significantly streamline your application modernization efforts, making the transition smoother and more efficient while taking advantage of the full power of the cloud. AWS offers a wide variety of different tools tailored to specific tasks, so you can choose the ones that work best for your requirements and needs.

Challenges and best practices of AWS application modernization

AWS application migration is a process with some specifics, and if you are planning to migrate to AWS, you need to understand the various aspects of the transition and best practices which will help you to avoid common challenges and reach the goal smoothly and fast. 

Here are some common challenges of AWS application modernization. 

1. Complexity of legacy systems

Legacy applications often have complex architectures, outdated technologies, and intricate dependencies that make modernization challenging. Understanding and untangling these dependencies can be a time-consuming and resource-intensive process.

2. Data migration

Migrating data from legacy applications to the cloud while ensuring data integrity and consistency is a significant challenge. It involves careful planning, robust migration strategies, and thorough testing to avoid data loss and breaches.

3. Security and compliance

Ensuring that applications and data meet security and compliance requirements in the new cloud environment is critical. This involves implementing robust security measures, such as identity and access management, encryption, and continuous monitoring, as well as adhering to industry-specific regulations like GDPR, HIPAA, and PCI DSS.

4. Application redesign

Rewriting or refactoring applications to take advantage of cloud-native features such as microservices, serverless computing, and containerization can be a complex and resource-intensive process. Ensuring that these changes do not disrupt business operations or degrade performance is essential.

5. Performance optimization

Ensuring that modernized applications perform optimally in the cloud environment is crucial. This involves continuous monitoring, performance tuning, and scaling to handle variable workloads efficiently.

6. Integration with existing systems

Modernized applications often need to integrate with other existing systems and services. Ensuring seamless integration while maintaining data flow and system interoperability is an important task your development team needs to take on. 

To deal with these challenges effectively and ensure smooth AWS application modernization, I recommend some best practices to implement during the transition. 

1. Adopt cloud-native architecture. Implement cloud-native solutions such as microservices, serverless computing, and containerization to efficiently modernize your applications on AWS. These solutions improve scalability, resilience, and resource utilization, allowing organizations to be more agile and innovative. 
2. Utilize managed services. Take advantage of AWS-managed services like Amazon RDS, Amazon Aurora, and AWS EKS to shift infrastructure management tasks, allowing you to concentrate on application development and innovation. These managed services offer built-in scalability, reliability, and security, accelerating your modernization efforts. 
3. Adopt a phased modernization approach. This approach allows the implementation of gradual updates, reducing disruptions and facilitating a smoother transition. It also provides the flexibility to adapt plans according to changing business needs and technological advancements.
4. Automate deployment and testing. Set up continuous integration and continuous deployment (CI/CD) pipelines using AWS services such as AWS CodePipeline, AWS CodeBuild, and AWS CodeDeploy to automate the deployment and testing of your applications. This automation streamlines the release process, reduces manual errors, and enhances overall software quality. 
5. Pay more attention to security and compliance. Emphasize security and compliance throughout the modernization process by implementing AWS security best practices and compliance standards such as HIPAA, GDPR, and PCI DSS. Use AWS services like AWS Identity and Access Management (IAM), AWS Key Management Service (KMS), and AWS Config to secure your applications and data in the cloud. 

AWS app migration success story:  Modernizing a Legacy CRM Application

The client approached us to address issues with their CRM product. They had tight deadlines, requiring the software to be updated within a month. 

In the course of the tech audit, our team revealed that the system used outdated technology versions and an inappropriate dedicated physical server, with only 1% of the paid capacity being utilized. So we were faced with the challenge of optimizing the code and infrastructure to ensure the system could meet growing business needs.

How we delivered: 

1. Built a new scalable cloud infrastructure
The legacy system was a monolithic architecture, with a server hosting the database and file storage. This setup made it challenging to scale the server load. Deploying new code also required manual FTP transfers to the server. To address these limitations, we provided cloud migration consulting and proposed using AWS as a test environment, which the client later selected as the cloud platform for the entire project. This allowed for the creation of a unified, optimized infrastructure.

To start, we migrated the database and file storage from the monolithic server to remote, cloud-based services (AWS RDS for the database, AWS S3 for file storage). Leveraging third-party cloud services provided higher stability and built-in backup mechanisms, which enhanced security and helped prevent data leaks.

The next step was to containerize the architecture using Docker, isolating each service (NGINX, PHP, Socket) into separate containers. This enabled the setup of a stable, automated CI/CD pipeline for code delivery to the server. It also provided opportunities to optimize server resource utilization.

AWS services used: AWS EC2, AWS ECR, AWS RDS PostgreSQL, AWS CloudFront, AWS S3, AWS IAM, AWS CloudWatch. 

By leveraging AWS, we were able to select the most appropriate instance types that met our requirements without being overpriced. This allowed us to provision resources that fully covered the needs of the product and its real-world user base.

2. Improved code quality under tight deadlines
The poor quality of the codebase led to additional challenges. We had to invest significant time in understanding the logic behind each method, even for minor changes. To address this, we adopted a gradual refactoring approach, focusing only on the specific functionality we were currently working on, and progressively addressing other parts of the code. This strategy enabled us to meet the deadline and optimize costs for the client. Over six months, with refactoring services provided, approximately 80% of the codebase had been optimized.

Business outcomes:

1. Improved Scalability and Performance: Transitioning from a monolithic server to a more scalable, cloud-based architecture allowed the application to handle increased user traffic and data volumes more effectively.
2.  Enhanced Agility and Flexibility: The modernized, cloud-native architecture made it possible to improve legacy code without significant delays in the release of new features. The development team can now deliver more consistently with less chance of human error. The ability to easily add or modify services, without impacting the entire application, increased the organization’s adaptability to market shifts and new opportunities.
3. Enhanced security: Third-party services are more stable and already have a backup mechanism that is more secure and helps to prevent data leakage.
4. Reduced Infrastructure and Operational Costs: Using AWS services has helped the company significantly reduce infrastructure overhead by allowing it to choose and pay only for the server resources it needs. Separate billing allowed the client to clearly see how much and for which servers the business was paying and manage it more efficiently.

MobiDev application modernization services: use AWS benefits to the fullest 

Migrating to the cloud with MobiDev ensures a seamless, efficient, and secure transition, leveraging over a decade of experience in building, scaling, and modernizing software products. 

Our in-house consultants and engineers start with a thorough audit of your software and existing infrastructure. This allows us to create a clear, strategic roadmap tailored to your business needs. From planning to execution, we take on the entire implementation process, ensuring every step is aligned with your business goals.

MobiDev’s in-house DevOps specialists are involved in streamlining the cloud migration process. By employing best practices and cutting-edge Cloud and DevOps tools, we reduce the risk of errors and ensure a smooth and successful transition to the cloud. Our experts have experience in handling complex migrations, minimizing downtimes, and ensuring your business continues to operate seamlessly. 

For a long time, MobiDev has been working with key cloud services such as Google Cloud, Azure, and AWS. This experience helps us understand the nuances of different cloud platforms and we can recommend the best solutions for your specific requirements. By choosing MobiDev’s consultants and engineers as your application modernization team, you benefit from experts who not only understand the technical complexities involved but also tailor solutions to your strategic business goals.