Application Replatforming Services That Reduce Cost Without Rewriting Code

Application replatforming involves making targeted changes to an existing application so it can run on a modern managed cloud platform — replacing a self-managed database with Amazon RDS, containerising the application for Kubernetes deployment, or upgrading the runtime from Java EE to Spring Boot — without redesigning the core business logic. Rehosting (lift-and-shift) moves the application with no changes at all, preserving the same runtime and infrastructure. Re-architecting redesigns the application from the ground up — breaking a monolith into microservices, adopting serverless, or rebuilding on a cloud-native architecture. Replatforming occupies the middle ground: more benefit than rehosting, far less risk and cost than re-architecting.

Replatforming is the right choice when the application's core business logic is sound, the problems are at the infrastructure or runtime layer, and the cost and timeline of a full rebuild cannot be justified. Typical replatforming triggers include: the current runtime has reached or is approaching end-of-life (Java EE, .NET Framework, PHP 7), the application is deployed on self-managed infrastructure with high operational overhead, the organisation wants to move to container-based deployment without rewriting application code, or the business needs cloud-native scaling and managed services without the 12–18 month timeline of a full re-architecture. If the application has fundamental design problems — a data model that cannot scale, tightly coupled logic that prevents independent deployment — replatforming alone will not fix those, and re-architecting may be a better long-term investment.

A typical application replatforming engagement runs six to eighteen weeks per application tier, depending on the complexity of the runtime migration, the number of database dependencies, and the extent of CI/CD modernisation required. Simple containerisation and managed database migration for a well-structured application can be completed in six to eight weeks. Runtime upgrades involving significant dependency changes — Java EE to Spring Boot, .NET Framework to .NET 8 — typically take ten to sixteen weeks including staging validation and load testing. We sequence replatforming to deliver early production wins on lower-complexity applications before tackling the most critical tiers.

Database dependencies are addressed as part of the replatforming scope, not treated as separate work. For applications using self-managed relational databases, we migrate to the equivalent managed service — Amazon RDS, Azure SQL, Google CloudSQL — using online replication tools that keep the managed database synchronised with the source during staging validation. For applications with tightly coupled stored procedure logic, we assess whether that logic should remain in the database or be extracted to the application tier as part of the replatforming. Schema modernisation — resolving deprecated syntax for new runtime versions, optimising indexes for the target database engine — is included in every database migration engagement.

We establish a staging environment that mirrors the production configuration of the replatformed application before any production traffic is shifted. Testing includes: functional regression testing against the existing test suite (supplemented by exploratory testing where test coverage is thin), load testing to validate performance against production throughput baselines, integration testing to verify all upstream and downstream service dependencies, and security scanning of the containerised application and its dependencies. For runtime upgrades (Java EE to Spring Boot, .NET Framework to .NET 8), we run the application against a test harness that validates business-critical workflows before the staging environment is signed off for production cutover.

Yes — containerisation is a standard deliverable in most replatforming engagements. We produce a production-grade Dockerfile, a Kubernetes deployment manifest or an equivalent managed container service configuration (AWS ECS, Azure App Service, Google Cloud Run), and a CI/CD pipeline that builds and publishes the container image on every code change. Container images are scanned for vulnerabilities as part of the build pipeline. For organisations not yet ready for Kubernetes, we can deploy to simpler managed container services (AWS Fargate, Azure Container Apps) as an intermediate step.

Cost savings from replatforming come from three main sources: infrastructure cost reduction from replacing self-managed servers with right-sized managed services; licence cost elimination from moving off unsupported runtime licences and on-premises database licences; and operational cost reduction from replacing manual server management with managed platform operations. Typical infrastructure cost reductions range from 20–40% against three-year total cost of ownership comparisons, depending on how over-provisioned the legacy infrastructure was. Runtime licence savings (particularly for .NET Framework on Windows Server) can be significant when migrating to Linux-based .NET 8 containers. We produce a pre-engagement cost model as part of the free discovery call.

We establish baseline metrics before replatforming begins — application response time under load, infrastructure cost per month, deployment frequency, mean time to recovery, and runtime vulnerability count — and measure the same metrics post-replatforming at 30 and 90 days. Successful replatforming engagements show: equivalent or improved application performance on the new runtime and infrastructure, reduced infrastructure cost, elimination of end-of-life runtime vulnerabilities, improved deployment frequency from CI/CD automation, and reduced operational overhead from managed services replacing self-managed infrastructure. We document outcomes against the original business case and produce a post-replatform report.

Replatforming to managed services does introduce a degree of platform dependency — Amazon RDS, Azure App Service, and Google Cloud Run are not interchangeable without configuration changes. However, this dependency is far more manageable than the vendor lock-in created by legacy proprietary runtimes and on-premises infrastructure. We mitigate managed service lock-in by using open standards where possible — PostgreSQL rather than Aurora-specific features, Kubernetes rather than a proprietary container orchestrator — and by documenting the platform-specific configuration choices made during replatforming so a future migration to a different cloud provider is a configuration exercise, not an engineering project.

The first step is a free discovery call in which we review your application estate — the runtimes, databases, infrastructure, and deployment processes you currently use — and identify which applications are candidates for replatforming versus re-architecture or rehosting. Following the discovery call, we produce a replatforming assessment document that categorises each application by replatforming complexity, estimated timeline, estimated cost, and expected outcomes. This assessment is provided at no cost and without obligation. If you decide to proceed, we move into a scoped engagement with a fixed-price statement of work covering the replatforming deliverables for the agreed application tiers.