Assessment
Code health, dependencies, security and hosting, with a chosen strategy for every component.
MODapplication modernisation services
Application modernisation services that keep your rankings.
Founcy Solutions' application modernisation services move legacy software (Web Forms, old .NET, AngularJS, ageing PHP) onto a supported stack one route at a time. A routing layer keeps public URLs identical while components are replaced underneath, so customers, integrations and search engines barely notice the switch.
- no big-bang rewrites
- tests before refactors
- urls kept stable
- legacy: Web Forms, VB.NET, SQL Server 2008, FTP deploys
- a routing proxy moves one component at a time
- modern: Razor Pages, .NET 10 services, Azure SQL, CI/CD
route by routepublic urls unchangedrollback at every phase
definition
What are application modernisation services?
Application modernisation services update ageing software so it is supported, secure and easier to change. That might mean rehosting it in the cloud, re-platforming it onto a current runtime, refactoring the code, or rebuilding parts of it. The safest approach is incremental: a routing layer sends some requests to new components and the rest to the old system, so parts are replaced one at a time while the business keeps running. For public-facing apps, the job also includes protecting the URLs, content and server-rendered pages that your search traffic depends on.
- Starting points
- .NET Framework, Web Forms, AngularJS, PHP 5/7, on-prem servers
- Strategies
- Rehost, replatform, refactor, rebuild or replace, chosen per component
- Method
- Strangler-fig routing, tests first, a parallel run before cutover
- Deadline
- .NET 8 and .NET 9 reach end of support on November 10, 2026
sound familiar?
Is your legacy app running on borrowed time?
Tick what's true today. It shapes the assessment we'd run first.
Tap anything that sounds familiar.
Book a modernisation assessment →what's included
Legacy application modernisation, without the cliff edge.
Every phase leaves you with working software and a way back. Here is what each engagement delivers.
Target architecture
A phased roadmap with a rollback point at every step and clear success measures.
SEO baseline
A crawl, URL inventory and top-traffic pages for any public-facing app, captured before work starts.
Tests first
Automated tests around current behaviour, written before anything is refactored or moved.
Migrated code
Components rehosted, re-platformed or rebuilt behind the routing layer, one at a time.
Data migration
Migration scripts plus reconciliation reports, so the numbers match before cutover.
Redirects & parity
A 1:1 redirect map where URLs must change, and a post-launch parity report.
Pipeline & handover
CI/CD, infrastructure as code, monitoring, a cutover runbook and a decommissioning plan.
modernise the stack, keep the rankings
The safest migration is one where URLs don't change.
Rewrites lose traffic when URLs move, content thins out, or server-rendered pages turn into a JavaScript-only app. Here's how a careful modernisation differs from a rewrite.
traffic risk: high
ApproachRewrite everything and launch over one weekendReplace route by route behind a reverse proxy
URLsNew framework, new URL schemePublic URLs kept identical; 1:1 permanent redirects only where change is unavoidable
RenderingServer pages swapped for a JavaScript-only appServer-rendered HTML kept on every public route
TestingManual checks in the week before launchAutomated tests written before code is touched
Verification"Traffic looks fine"Before-and-after crawl diff: titles, canonicals, schema, links, status codes
RollbackNone, so forward is the only way outAn agreed rollback point at every phase
how it works
Five phases, each one reversible.
The old system keeps working until the new one has proven itself, component by component.
- 01
Assess
Inventory the app, score risk and business value, and capture an SEO and analytics baseline.
→ assessment report - 02
Plan
Pick a strategy per component, sequence the work, design the routing layer and agree success metrics.
→ phased roadmap - 03
Migrate incrementally
Tests first, then components behind strangler routing, then a parallel run while the outputs are compared.
→ components live behind the proxy - 04
Cut over
Shift traffic in stages, with redirects live, monitoring on and rollback ready.
→ parity report - 05
Optimise
Retire the old system, then tune cost, performance and Core Web Vitals on the new platform.
→ decommissioning sign-off
stack
From where you are to where you're going.
// runtime
.NET 10ASP.NET CoreRazor PagesBlazorJava / Spring BootNode.js
// routing & infra
YARPDockerAzure Container AppsAKSEKSTerraformBicep
// data & messaging
SQL ServerAzure SQLPostgreSQLService BusKafka
// delivery & seo qa
GitHub ActionsAzure DevOpsScreaming FrogSitebulbSearch Console
what drives the cost
What will modernising your app take?
The size of the job comes down to four things. Set them to see the kind of programme you're looking at.
keep exploring
Related services.
NET
ASP.NET development
Upgrade to .NET 10 LTS before .NET 8 and 9 lose support.
Explore → AZRAzure app development
Move modernised workloads onto Azure services.
Explore → CLDCloud applications
Re-architect for the cloud when rehosting isn't enough.
Explore → APIAPI development
Expose legacy data through a clean API while the rest moves.
Explore →faq
Modernisation questions.
They're shorthand for the options: rehost, refactor, revise, rebuild and replace in Gartner's version, while AWS's migration strategies add retire, retain, relocate and repurchase. Different components of one application often get different Rs.
Mostly, yes. Incremental routing, blue-green or slot deployments and a parallel run keep the application available. Some data cutovers need a short window, which is planned, rehearsed and scheduled for low traffic.
The risk comes from changes to URLs, content or rendering. We keep URLs stable where we can and redirect one-to-one where we can't, and server rendering stays on public pages. Google says to expect some temporary fluctuation during moves; monitoring catches real regressions early.
Codebase size and quality, existing test coverage, the number of integrations, data volume and complexity, how far you're moving (rehost versus rebuild), compliance needs, and how long the parallel run lasts.
.NET 8 and .NET 9 reach end of support on November 10, 2026, so plan the move to .NET 10 LTS, which is supported until November 2028. .NET Framework 4.8.x still gets security fixes with Windows but no new features; moving off it means package-by-package compatibility work.
Big-bang rewrites carry the most risk; incremental refactoring keeps the business running while value ships. We decide per component, weighing business value against code health, and rebuild only where that clearly wins.
start with an assessment
Retire the legacy. Keep the traffic.
Tell us what you're running and where it's public-facing. We'll assess the code and the search footprint together and propose a phased path.
quote within 24 hours · rollback point at every phase · rankings protected