By Stratos UI, the long-standing open source frontend for Cloud Foundry, has reached the end of its viable life. Accumulated technical debt makes it economically unsustainable to add features or maintain security. Enterprise platform teams running Cloud Foundry need a replacement that matches the pace of modern platform engineering.
In this interview on TFiR, Julian Fischer, CEO at anynines, breaks down why Stratos UI had to be retired, how CF AppStage was built on Backstage and Cloud Foundry API v3, and how this UI layer extends across Klutch and anynines data services.
Guest: Julian Fischer, CEO at anynines
Show: Cloud: Evolution
LinkedIn: Julian Fischer
Watch the discussion on YouTube
Here is what every platform engineer and Cloud Foundry operator needs to know.
Technical Deep Dive
Q: Why is Stratos UI no longer a viable frontend for Cloud Foundry?
Julian Fischer, CEO at anynines, explains that Stratos UI accumulated technical debt to the point where shipping new features and maintaining security became economically unsustainable. The maintenance burden grew while active development slowed, leaving enterprise teams exposed to compounding risk with no clear upgrade path. The combination of reduced community maintenance and growing debt made continued investment in Stratos indefensible.
“The technical debt accumulating in that project led to a point where developing new features and keeping the system secure is not economically maintainable and sustainable anymore.”
Julian Fischer, CEO, anynines
Q: What is CF AppStage and what does it replace?
CF AppStage is a direct replacement for Stratos UI, built on Backstage and Cloud Foundry API v3. Fischer describes it as blazingly fast and easy to use, designed to serve the same enterprise audience that previously relied on Stratos for managing Cloud Foundry applications through a UI. It addresses both the usability gap and the maintainability problem left by Stratos’s decline.
“CF AppStage is a replacement for the Stratos UI. It is built on Cloud Foundry API v3. It’s blazingly fast and easy to use.”
Julian Fischer, CEO, anynines
Q: Why was Backstage chosen as the foundation for CF AppStage?
Fischer positions Backstage as the standard approach to building developer and platform UIs in 2025 and 2026, making it the logical foundation for any new Cloud Foundry frontend. The choice reflects where the broader platform engineering community is investing, ensuring CF AppStage benefits from ecosystem momentum and long-term maintainability. Backstage also provides the extensibility anynines needs to unify multiple products under one UI layer.
“Backstage is the way to go for building UIs in 2025 and 2026.”
Julian Fischer, CEO, anynines
Q: How does CF AppStage fit into the broader anynines platform beyond Cloud Foundry?
The same team building CF AppStage is extending the Backstage-based UI framework to Klutch, a9s Hub, and anynines data services. Fischer describes Backstage as the new unified frontend for the entire anynines ecosystem, serving both platform engineers and application developers. This means the investment in CF AppStage is not isolated to Cloud Foundry but is the foundation for a consistent UI strategy across the full anynines product portfolio.
“Backstage is essentially the new front end for the anynines platform, Cloud Foundry, and anynines data services, as well as for a9s Hub, including Klutch and all the integrations we have there.”
Julian Fischer, CEO, anynines
Q: Do enterprise Cloud Foundry users still rely on a UI rather than the CLI or API?
Fischer confirms that a significant portion of enterprise Cloud Foundry customers continue to manage applications through a UI, even though the CLI and API are the preferred interfaces for most operations. This sustained demand was a direct driver for investing in CF AppStage rather than deprecating UI-based management entirely. The existence of this user segment makes a well-maintained, modern UI a practical requirement, not an optional convenience.
“You’d be surprised how many enterprise customers still use the UI to fiddle around with their applications.”
Julian Fischer, CEO, anynines
Resources & Documentation
- anynines, enterprise Cloud Foundry distribution, data services, and the Klutch platform engineering product
- Backstage, open source framework for building internal developer portals, the foundation for CF AppStage
- Cloud Foundry API v3, the API layer underlying CF AppStage
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👇 Click to Read Full Raw Transcript
Swapnil Bhartiya: That’s true. Is it possible for you to also touch on CF AppStage as well? And how does it fit into the platform engineering? You know,
Julian Fischer: absolutely. I mean, in the Cloud Foundry ecosystem, you either come from a commercial Cloud Foundry distribution, which usually has some sort of UI to manage your applications, and you’d be surprised how many enterprise customers still use the UI to fiddle around with their applications. Although the CLI or the API would be the preferred. Well, it is a demand. So we had Stratus UI as an open source project, but it didn’t age well. There’s less maintenance going on there, and the technical debt accumulating in that project led to a point where developing more features, new features and keeping the system secure is not economically maintainable and sustainable anymore.
So we decided to build a replacement that is entirely based on Backstage, which is the way to go in 2025 and 2026 on building UIs. So CF AppStage is a stratus UI replacement. It’s built on the Cloud Foundry API version 3. It’s blazingly fast, easy to use, and the team we’ve built building CF AppStage is going to continue to build a similar UI framework for platform engineers as well as application developers for Klutch as well. So Backstage is basically the new front end for any9’s platform Cloud Foundry and any9’s data services, but also for any9’s hub. With Klutch and all the integrations we got there.
