AWS Application Modernization
Legacy monoliths slow every release and make outages harder to diagnose. We modernize apps on AWS incrementally — containers, serverless, or microservices — with working software at every stage. Start with a free modernization assessment: 6 Rs roadmap, TCO comparison, and a prioritized plan with no obligation to proceed.
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Application modernization is the process of updating legacy applications and architectures to align with cloud-native capabilities. The goal is not modernization for its own sake — it is enabling your team to ship faster, scale more efficiently, and operate with less overhead.
Legacy applications accumulate technical debt over years: monolithic codebases where every deployment is a risk, on-premises databases with expensive licenses, manual deployment processes that take hours, and architectures that cannot scale horizontally without significant rework.
Modernization removes these constraints incrementally, delivering business value at each step.
AWS defines six strategies for modernizing applications. The right strategy for each workload depends on its complexity, business value, compliance requirements, and modernization cost.
Move the application to AWS with no changes to the application itself. Run on EC2 the same way it ran on-premises.
When to use: Applications with inflexible architectures, short timelines, or where the primary goal is eliminating on-premises infrastructure costs. Rehost first, optimize later.
Tools: AWS Transform MGN (formerly AWS Application Migration Service), VM Import/Export.
Move to AWS with small optimizations — switch to RDS instead of self-managed MySQL, use Elastic Beanstalk instead of manually configured EC2, or move to containers without changing application code.
When to use: Applications that can benefit from managed services without code changes. Replatforming reduces operational overhead without the risk or cost of a full refactor.
Example: Move a Java application from on-premises Tomcat to AWS Elastic Beanstalk. Same code, managed infrastructure, automatic scaling.
Modify the application to use cloud-native services and patterns. Break a monolith into microservices, adopt event-driven architecture, or restructure around managed services.
When to use: Applications with clear scaling bottlenecks, high deployment risk due to monolithic architecture, or significant business value that justifies higher modernization investment.
Example: Extract the payment processing module from a monolith into an independent service on ECS with its own Aurora database, communicating through EventBridge.
Fully redesign the application from scratch using cloud-native patterns — serverless, event-driven, microservices from the ground up.
When to use: Applications at end-of-life where the existing codebase is a liability, or greenfield capabilities where you have the opportunity to design correctly from the start.
Example: Replace a batch-processing monolith with a serverless pipeline using S3 events, Lambda, Step Functions, and DynamoDB.
Decommission the application entirely. It no longer serves a business need, or its functionality is now covered by another system.
When to use: Duplicate systems, applications with no active users, or functionality absorbed into another product.
Keep the application as-is, either on-premises or on AWS. Not every application should be modernized.
When to use: Applications that work, are rarely changed, have no scaling requirements, and where modernization cost exceeds business benefit. Mainframe systems that perform critical batch processing are a common example.
A modernization assessment is not a sales call dressed up as architecture review. In 1–2 weeks we produce an auditable deliverable:
What you get: A prioritized roadmap your CTO can take to the board — whether or not you engage us for execution.
Book a Free Modernization Assessment →
We begin with an application portfolio assessment that maps each application to an appropriate 6 Rs strategy:
The output is a prioritized roadmap: quick wins (Rehost/Replatform) that deliver immediate value, followed by higher-value refactoring for critical workloads.
For Refactor and Rearchitect paths, we design the target architecture before writing code:
We implement the modernization incrementally using the Strangler Fig pattern where possible:
Post-migration optimization to extract full cloud-native value:
| Layer | Technologies |
|---|---|
| Container orchestration | Amazon ECS, Amazon EKS, AWS Fargate |
| Serverless compute | AWS Lambda, AWS Step Functions |
| API management | Amazon API Gateway, AWS AppSync |
| Event-driven architecture | Amazon EventBridge, Amazon SQS, Amazon SNS |
| Database modernization | RDS, Aurora, DynamoDB, ElastiCache |
| CI/CD | AWS CodePipeline, GitHub Actions, GitLab CI |
| Infrastructure as code | AWS CDK, Terraform, CloudFormation |
| Observability | CloudWatch, AWS X-Ray, OpenTelemetry |
For a comparison of containerization approaches, see AWS ECS vs EKS and our guide on Microservices vs Monolith Architecture on AWS.
For the migration component of modernization, see our AWS Cloud Migration Services. For serverless implementation, see AWS Serverless Architecture. For the CI/CD pipeline automation that modernized applications need, see AWS DevOps Consulting.
Free evaluation of your application portfolio against the 6 Rs framework. We tell you which workloads to modernize, which to rehost, and which to retire — with a prioritized roadmap and TCO comparison for each decision.
Package monolithic applications into containers for consistent deployments, environment parity, and horizontal scaling on Amazon ECS or EKS.
Decompose appropriate components into Lambda functions and event-driven architectures — eliminating server management and reducing compute costs.
Break monoliths into independently deployable services using the Strangler Fig pattern — incrementally, with working software at every stage.
Migrate from legacy databases (Oracle, SQL Server) to managed services — RDS, Aurora, DynamoDB — reducing licensing cost and operational overhead.
Replace manual deployment processes with automated CI/CD pipelines using CodePipeline, GitHub Actions, or GitLab CI — enabling multiple deployments per day. Lambda targets default to Node.js 22/24 (Node.js 24 supported through April 2028) or Python 3.13, with SnapStart (now GA for Python 3.12+ and .NET 8+) where startup latency matters.
We are not a lift-and-shift shop. We assess each workload against the 6 Rs framework and recommend the right path — including Retain or Retire when modernization cost exceeds the business benefit. Not every application should be refactored.
We deliver working software at every stage — no big bang rewrites that take 18 months and deliver nothing in between.
We assess modernization risk before recommending approach. Some workloads should be rehosted, not refactored. We tell you which is which.
Java, Node.js, Python, .NET, PHP — we have modernized applications across every major stack onto AWS. Regulated industries (healthcare, fintech) get extra attention to compliance continuity throughout the migration.
Verticalized engagements aligned to industry threat models, compliance, and reference architectures.
Legacy financial systems cost millions annually in maintenance. We modernize banking platforms from mainframe/COBOL to cloud-native architecture, reducing operational costs and enabling innovation.
Healthcare organizations run legacy EHR systems on expensive infrastructure. We modernize EHRs to cloud-native, interoperable platforms that improve clinical workflow and reduce operational costs.
Implementation guides for this service from our team of AWS experts.
Q2 2026 ranked: AgentCore Harness GA (Jun 17), FinOps Agent preview (Jun 9), Graviton5 GA (Jun 10), OpenAI on Bedrock (Apr 28). Adoption matrix + verified TCO signals for CTOs.
On a 120-stack AWS Organization, CloudFormation StackSets for platform baseline plus CDK for app teams cut org-wide guardrail rollout from 6 weeks to 2 — with Application Composer for spikes and Blocks for greenfield TypeScript only at preview.
AWS Blocks (public preview, June 2026): 18+ open-source TypeScript building blocks that run locally without an AWS account and deploy with zero code changes.
AWS shipped ECS Express Mode on November 21, 2025 — three inputs (image + two IAM roles) and Express Mode provisions Fargate, ALB, HTTPS, auto scaling, and a *.ecs.*.on.aws URL. Up to 25 services can share one ALB. No Express Mode surcharge.
Refactor, replatform, or rearchitect — pick the path that matches value and risk. July 2026 refresh: 6R framing, AWS Transform for mainframe, when strangler fig fails.
Build a data-driven business case for application modernization. ROI calculations, cost-benefit analysis, risk frameworks, and board-ready presentations.
July 2026 decision guide: monolith → modular monolith → microservices on AWS — team size, platform tax (VPC Lattice/mesh), and a checklist before you split for the org chart.
The difference between a successful AWS migration and a costly failure often comes down to strategy. A practical guide to choosing the right migration approach, building your roadmap, and avoiding the pitfalls that derail most projects.
On a composite B2B order API (~2.4k RPS peak, 24 ECS tasks on Aurora), running the scaling ladder in order — RDS Proxy, read-replica routing, ElastiCache, then SQS offload — moved modeled p99 from 1,840 ms to 72 ms before any microservice split.
For a .NET monolith (~220 endpoints, ~$28k/mo EC2), strangling 14 endpoints to Lambda cut p95 on those routes 1.4s → 210ms — an early LMI move on spiky traffic wasted ~$3.2k in idle capacity provider hours.
For a mid-market retailer (~2.4M SKUs, checkout p95 1.9s → 420ms), DynamoDB cart + Step Functions checkout + conditional inventory cuts held 2.1k checkout RPS — after a cache-as-inventory mistake oversold 380 units in 12 minutes.
Third-party tools we frequently wire into AWS as part of this engagement — production-tested integration guides for each.
Amazon EKS in 2026: Auto Mode GA, Hybrid Nodes, Karpenter 1.0, Pod Identity, Graviton-first node pools, and ECR enhanced scanning — cheaper, safer K8s.
GitHub Actions to AWS in 2026: OIDC keyless auth, Artifact Attestations, Immutable Actions, ARM runners, and reusable workflows to ECS, Lambda, EKS.
Terraform + AWS in 2026: Stacks GA, ephemeral values, provider-defined functions, Test Framework, OpenTofu 1.8 encryption — vs CDK and CloudFormation.
Architecture patterns, decision trees, and glossary terms that map to this engagement.
Production event-driven architecture on AWS — EventBridge custom buses, EventBridge Pipes for the transactional outbox, SQS dead-letter queues, Step Functions for orchestration, and Lambda or Fargate workers. Decouple services without dual-writes.
Amazon Elastic Kubernetes Service — fully managed Kubernetes control plane for running containerized applications at scale on AWS.
Serverless compute service that runs code in response to events without provisioning or managing servers.
In-depth guides and best practices from our certified AWS architects.
Assume 8 state transitions and 200 approved signups in a month: 1,600 transitions. Step Functions Standard includes 4,000 free transitions a month in US East (N. Virginia) at $0.000025 after that. The workflow marks READY only after the health check.
Read articlePutRestoreValidationResult accepts FAILED, SUCCESSFUL, TIMED_OUT, or VALIDATING. Once the status is set, AWS says it cannot be changed. A completed restore job is not an application check until you run one.
Read articleDelete is a late state. A legal hold stops the machine in HELD. One Scheduler invocation on the retention date sits inside the 14 million free EventBridge Scheduler invocations a month. The first write revokes access. It does not delete objects.
Read articleIn-depth comparisons to help you choose the right approach before engaging.
Practical comparison of Amazon ECS vs EKS. Container orchestration, scaling, operational overhead, and when to choose each.
Detailed comparison of AWS Lambda vs ECS Fargate. Execution time, cold starts, cost, and architectural tradeoffs.
Objective comparison of AWS vs Microsoft Azure for enterprise workloads. Features, pricing, compliance, and strategic fit.
Maps your full application portfolio to the right modernization strategy and delivers a prioritized roadmap with ROI estimates — no commitment to proceed.
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