In recent months, I’ve created visual tools to help people make sense of Microsoft’s most important cloud frameworks:
The Cloud Adoption Framework (CAF) – Microsoft’s end-to-end cloud journey guidance
The Well-Architected Framework (WAF) – principles for designing secure, reliable, and cost-effective workloads
These two frameworks underpin how organisations plan, govern, and build in Azure.
But at Microsoft Build (May 2025), a new addition quietly joined the party: the App Modernisation Guidance – a focused set of recommendations and patterns to help organisations bring legacy apps into the modern cloud world.
Where CAF shows you the overall journey and WAF ensures your workloads are well built, this new guidance zooms in on one of the most complex (and valuable) pieces of the puzzle – modernising legacy applications for the cloud.
What is the Microsoft App Modernisation Guidance?
The Microsoft App Modernisation Guidance is part of the wider Cloud Adoption Framework. It provides a practical, structured lifecycle to help organisations move from legacy systems to modern, cloud-native applications on Azure.
It breaks the journey into seven clear phases:
Get Started – Learn the lifecycle, define your roadmap, and assess where you are
Assess – Evaluate app portfolios, gather inventory, and check cloud readiness
Plan – Choose the right strategy using Microsoft’s 6 Rs (Rehost, Refactor, Rebuild, etc.)
Launch – Run a proof of concept, and embed identity, security, and compliance
Foundation – Set the groundwork for specific stacks like .NET, Java, SAP, Oracle, VMware
Expand – Rebuild using APIs, microservices, serverless platforms, and data modernisation
Innovate & Optimise – Introduce AI, low-code, performance, and scale improvements
Why does modernisation matter?
Modernising applications isn’t just a technical upgrade – it’s a business enabler. Most organisations still rely on legacy systems that are hard to scale, expensive to run, and difficult to integrate with modern services.
Modernisation helps you:
Deliver faster and adapt to change
Reduce technical debt and support overhead
Enable AI, analytics, and low-code tools
Improve performance, security, and scalability
Unlock agility and business value from your existing assets
This guidance provides structure and clarity for what can otherwise feel like an overwhelming task.
How does it relate to CAF and WAF?
Here’s the relationship in simple terms:
CAF = the full cloud journey
App Modernisation Guidance \= the "modernise your apps" part of that journey
WAF = best practices to make sure your apps are well-architected, secure, and scalable
The App Modernisation Guidance slots directly into CAF’s Modernise phase and can be used alongside WAF to validate the architecture of replatformed or rebuilt workloads.
AI-powered modernisation with Copilot
Microsoft is also bringing AI into the process. The GitHub Copilot Upgrade Assistants help speed up app modernisation by offering intelligent recommendations and automated code changes.
These tools can save a significant amount of time when migrating large legacy estates, and are well worth a try.
Why I built a visual explorer for this guidance
Like many others, I’ve found real value in having a visual, structured view of large Microsoft frameworks. After publishing explorers for CAF, WAF, and Microsoft AI Adoption, I wanted to do the same for this new addition.
The Markmap Visual Explorer for the App Modernisation Guidance lays out all seven phases in a single interactive map – with direct links to Microsoft’s official documentation.
It’s built for architects, developers, IT leads – anyone planning or delivering app modernisation.
📦 GitHub Repository
🗺 Launch Interactive Map
Final thoughts
In my opinion, this guidance is a real value-add to the Cloud Adoption Framework.
It helps clear away much of the ambiguity around how to get from A to B in the cloud – offering practical, grounded steps that go beyond theory. It’s not just about moving tech – it’s about aligning modernisation efforts to real business outcomes, in a way that’s measurable, focused, and easy to understand.
If you’re modernising legacy systems or preparing to – this is worth your time.
And if you want the big picture at a glance – give the Markmap a try.
A quick note on spelling…
You may notice a mix of UK and US spelling in this post. I’m based in the UK and follow British spelling conventions (like modernisation and optimise), but I also use Microsoft's official product names and terminology (like App Modernization Guidance) as they appear in the documentation - which typically uses US spelling. It’s a deliberate mix to keep things both accurate and readable.
