Compliance-first delivery
Modernise incrementally, ship continuously
Legacy systems rarely fail all at once; they become slower to change, harder to hire for and riskier to patch. Old frameworks drop out of support, deployments need downtime, and nobody dares touch the module that calculates invoices. Yet the big-bang rewrite most teams reach for is the riskiest option of all — it freezes the business for months and often ends up recreating the same problems.
We modernise using the strangler-fig pattern. First we put a safety net around the existing system: characterisation tests, logging and monitoring so we know what “working” looks like. Then we route traffic through a facade and replace capabilities one slice at a time — extracting a service, upgrading a framework, moving a database — with each step independently deployable and reversible. Containerisation and migration onto modern infrastructure follow our cloud infrastructure practice, and new delivery pipelines come from DevOps automation.
The result is a system on supported technology, with tests, CI/CD and observability, delivered without a long feature freeze. Where the legacy is PHP, our PHP and Laravel specialists handle version upgrades and refactoring; where it is a set of brittle point-to-point connections, we rebuild them as a clean integration layer.
- Incremental, reversible changes instead of a big-bang rewrite
- Characterisation tests and monitoring before code changes
- Framework, language and database upgrades
- Containerisation and migration to managed cloud services
- Security uplift: modern auth, patched dependencies, secrets management
What's Included
Everything you need, delivered by a senior, security-first team.
Legacy Assessment
Code, dependency and architecture review with a risk-ranked modernisation roadmap.
Test Harness
Characterisation and integration tests that pin down current behaviour before changes.
Strangler-Fig Re-Architecture
Extract capabilities behind a facade into clean services, one slice at a time.
Containerisation
Docker images, Kubernetes or managed container hosting, and twelve-factor configuration.
Data Migration
Schema evolution, dual-write or replication strategies and verified data cutovers.
Security Uplift
Modern authentication, dependency upgrades, secrets out of code and hardened runtime.
Modernise without betting the business on a rewrite
Legacy applications usually still work — that is why they are hard to replace. The problems are slow releases, scarce skills, unsupported runtimes, rising hosting costs and security findings that cannot be fixed without touching fragile code. A full rewrite promises a clean slate but often runs for years while the old system keeps changing. We modernise incrementally: putting tests around what exists, carving off pieces behind stable interfaces and moving them to cloud-native platforms while the business keeps running.
Signs it is time to modernise
- The application runs on an end-of-life language version, framework or operating system.
- Releases are rare because every change risks breaking something unrelated.
- Scaling means buying a bigger server.
- Penetration tests or audits raise findings that cannot be fixed in the current architecture.
- Only one or two people understand how it works.
Modernisation options compared
| Approach | What it involves | Risk | When it fits |
|---|---|---|---|
| Rehost | Move as-is to cloud VMs | Low | Data-centre exit deadlines |
| Re-platform / containerise | Containers, managed databases, CI/CD | Low–medium | Quick operational gains with little code change |
| Refactor (strangler fig) | Extract modules into services behind an API facade, piece by piece | Medium, controlled | Core systems that must keep evolving |
| Rewrite | Rebuild from scratch | High | Small systems or when the domain has fundamentally changed |
Our approach
1. Assess the portfolio
We review code quality, dependencies, data model, infrastructure, security findings and business criticality, then recommend an approach per application rather than one strategy for everything.
2. Build a safety net
Characterisation tests capture current behaviour before anything changes, and a CI pipeline runs them on every commit.
3. Containerise and automate
Packaging the application in containers with infrastructure as code gives repeatable environments and is often the quickest win. Our DevOps automation team handles the pipelines and Kubernetes or managed-container setup.
4. Strangle, do not replace
Using the strangler-fig pattern, new or high-change capabilities are built as separate services behind a routing layer, while the old code paths are retired gradually. Data is migrated with dual-write or change-data-capture where needed.
5. Uplift security and operations
Upgraded runtimes, patched dependencies, secrets moved to a vault, modern authentication, and monitoring in place before each cut-over.
Common pitfalls
- Splitting a monolith into dozens of microservices that still share one database.
- Freezing feature work for a year-long rewrite.
- Migrating to the cloud without changing anything, then being surprised by the bill — see our FinOps playbook.
- No tests, so nobody can prove the new version behaves like the old one.
Deliverables
- Modernisation assessment and per-application roadmap.
- Automated test harness and CI/CD pipeline.
- Containerised, cloud-hosted application with infrastructure as code.
- Incrementally extracted services and decommissioning plan for legacy components.
Related services
Modernisation often runs alongside a cloud migration and new feature work by our custom software development team. For legacy PHP applications specifically, see PHP and WordPress services.
Our Modernisation Approach
Assess
Understand the system, its users and its risks; agree target architecture and the first slice.
Safety Net
Add tests, logging and monitoring so behaviour changes are visible immediately.
Replace in Slices
Route through a facade and modernise one capability at a time, each deployable on its own.
Retire
Decommission legacy components once traffic and data have fully moved across.
Frequently Asked Questions
It is the process of updating legacy software — its architecture, runtime, infrastructure and delivery process — so it is easier to change, cheaper to run and more secure, ideally without stopping the business while it happens.
Rarely. Full rewrites are high-risk because the old system keeps changing while the new one is built. Incremental approaches such as containerising first and then extracting services with the strangler-fig pattern deliver value sooner with far less risk.
Quick wins such as containerisation and CI/CD can arrive within weeks. Extracting services from a large monolith is usually a phased programme over several months, delivering improvements at each step.
The assessment is a fixed-price engagement. Implementation is scoped per phase, either fixed-price or as a dedicated team billed monthly, so you can stop or re-prioritise between phases.
Common examples include legacy PHP, Java, .NET Framework and Python applications, older databases and on-premises or VM-based deployments, which we move towards containers, managed databases and modern frameworks.
Book a free consultation. We discuss the application and its pain points, then propose an assessment with a clear modernisation roadmap.
Ready to get started with Application Modernization?
Book a free consultation — we'll map a secure, practical path forward.