By Richard Lander, CTO | September 16, 2025
The term "application platform" has been both overused and very poorly defined. In this blog post, I will provide an expanded definition. I will also address some of the nonsensical things that are commonly lumped into the definition of an application platform. Then, I'll provide more context and detail by discussing the management concerns and important characteristics of app platforms. Finally, we'll look at some examples. But first, a rant.
Poorly Defined Terms are the WORST
Poorly defined terms are cancerous to the effective application of a technology or subject. If terms are not useful and commonly understood, reasoning is impaired and implementations are botched.
Well-defined terms are the bedrock of human understanding. Useful terms distill subjects by making helpful distinctions that provide logical clarity. They facilitate individual reasoning, knowledge transfer and shared comprehension.
Application platforms are critical to the smooth delivery of software to remote servers. And, as an industry, we're not doing a great job of this. The prevalence of poor definitions is not helping.
With that said, let's define "application platform."
Definition of Application Platform
An application platform is a system that delivers software services to their remote runtime environments to make them available to end users.
Note the reference to "remote runtime environments." This is to constrain the scope to software running on servers in a data center. App platforms are not used to deliver software that is installed on consumer devices.
An application platform is where you put a release of your application so it can be rolled out and made available to your end users.
An application platform abstracts cloud providers, infrastructure and runtime environments so that the same app can be run in different places. Furthermore, if different components of an app use different providers or runtime environments, the app platform can orchestrate delivery of the entire distributed system.
An application platform satisfies dependencies for your application. An app needs a relational database? The app platform will provision (if needed) the DB and connect it. The app needs to be monitored? The app platform will connect the app to observability systems.
An application platform is designed to handle software systems that have multiple components. They're designed to accommodate distributed systems using microservices architecture with complex requirements.
An application platform is a software delivery system.
So now that we are clear about what an app platform IS, let's discuss what it is NOT.
What an Application Platform is NOT
Please note the definition above includes nothing about developer tools. As long as a piece of software and its intended runtime environment are supported by the platform, it doesn't matter at all what tools were used to build it. The US Postal Service is a platform for delivering mail. You can write a letter on whatever paper you choose, use whichever pen you like. You can use an old typewriter, or a computer and printer. It *doesn't matter*. The tools that create the artifact should NEVER matter to the platform as long as compatibility is intact.
Neither is there any reference to build pipelines. Again, how binary or container image artifacts are built is irrelevant to an app platform. An app platform merely needs to know where it can find the relevant build artifacts to deliver them. The postal service doesn't care what brand of envelope you use or how you seal it. As long as it's a standard size and shape, they will sort it and deliver it to the intended destination.
Also, note there is nothing about operating systems in this definition. An OS is a platform for individual programs on a single machine. An OS provides an interface between programs and computer hardware. An app platform provides an interface between applications - which commonly consist of many individual programs on different machines - and any number of runtime environments with potentially varying operating systems. Operating systems and application platforms tackle different concerns at different layers.
None of these things are useful to include when defining an app platform. Some vendors will bundle as many things as they can and apply catchy buzzwords to sell you things you don't need. But that doesn't make it sensible.
Hopefully, it is now becoming much clearer what a useful definition of application platform is. Let's add greater detail with a look at the management concerns of an app platform.
Management Concerns
Following are the four broad concerns that are abstracted and managed by an application platform.
Infrastructure
An application platform provisions resources or identifies capacity for your app to use. The necessary compute, storage and networking is set up to host your app and provide the bare necessities to run.
Part of the concern of an app platform is to abstract provider-specific implementations of runtime infrastructure.
Runtime Environment
An application platform abstracts the runtime environment. A runtime environment is characterized by the interface that is used to install and run the app. Below are some examples of runtime environments with their interfaces.
- A Linux server in a cloud provider's data center: The interface in this case is the filesystem and Linux kernel because we generally write files to the filesystem and issue commands to the kernel in order to install and run app workloads.
- Kubernetes cluster: The interface here is the Kubernetes API. We create Kubernetes resources and the K8s control plane runs containers in a cluster of machines.
- Managed services such as AWS Lambda or Google Cloud Run: In this case we interface with cloud provider APIs so that our code gets run in their walled gardens.
An application platform allows you to run your application on the right runtime environment based on your requirements and allows you to manage distributed apps coherently when different components are designed for different runtime environments.
Dependencies
Few modern applications run in isolation. In addition to infrastructure and runtime environments, they need network services, DNS records, access to secrets, databases, object stores, integration with observability systems, etc. An application platform allows developers to define their app's dependencies and takes care of the minutia of satisfying those dependencies.
Workloads
Finally, obviously, the app platform manages the deployment, update, upgrade and decommissioning of the workloads that comprise an application. The infrastructure, runtime environments and dependencies are all managed in service of the workload.
Now that we have covered what an app platform is, what it is *not* and what it does, let's dive into the important characteristics to help you discern the good from the bad in app platforms.
Important Characteristics
Following are the most important fundamental characteristics of an app platform. These are provided here to help identify the relative usefulness of different app platforms. A definition of a thing that doesn't include a way to determine the quality of that thing is incomplete.
Extensibility
An application platform must be readily extensible for different use cases. Platforms, by their nature, are general purpose mechanisms. General purpose systems are good for consolidating workflows but can be inefficient for more specialized and advanced use cases. If 95% of your workloads are supported out of the box by a particular app platform, your software delivery problems are NOT 95% solved. That last 5% may consume a wildly disproportionate amount of engineering effort in workarounds, integrations and mishap correction.
However, if your application platform is inherently and readily extensible, you can add the functionality you need to cover 100% of your use cases with comparatively little effort. You can consolidate your systems, optimize your operations and enable self-service capabilities that have profound compounding effects on your development velocity and productivity.
A good application platform provides primitives for the management concerns listed above. It also provides a native mechanism for abstracting those concerns to serve more specific use cases with modular plugins. This is the key to building systems that last.
Scalability
The scalability of an application platform is not a problem until the exact moment it is. Scalability is the storm cloud on the horizon that won't affect you until the day your business is successful enough to need it. It is often said that "scaling problems are good problems to have." This is true, but if, when you get there, you find you cannot scale without major overhauls and refactors, your business' success will also be its curse.
Failing to plan for scaling is like failing to plan for retirement. If you succeed in making it to old age but find yourself broke and destitute, you have not succeeded. If your company's software becomes popular enough for a lot of people to want to use it, but you can't scale to meet demand without compromising the quality of your product, your business has not succeeded.
The same applies to application platforms. If the number of runtime environments, dependencies and/or workloads scale to a volume that causes your app platform to choke, you have a terrible problem. Your options are to migrate to a different platform that *does scale* or implement workarounds such as complex layers of federation that are often devastating to an organization's efficiency and effectiveness in delivering their software.
Resilience
Software fails, servers fail, networks fail, electricity grids fail. High availability, especially across geographic regions is the primary way we mitigate the impact of these failures. The more critical the system, the more resilient it must be to various failures. Few systems are more critical than those we use to deliver our software to their runtime environments.
If your cloud provider has a regional outage in a region where you host mission-critical apps - and if your app platform is also running there - you will have a memorable day for all the wrong reasons. When your mission-critical apps experience any kind of outage, your app platform must remain available to perform any needed failovers or mitigation actions.
Auditability
The ability to see how a system was configured and who took the actions to get there is important in a variety of situations. Downtime incidents and security breaches require investigation. Compliance reports require attestation.
A capable application platform provides mechanisms to record this data and provide efficient means to access it.
Everything Else
There are many other secondary characteristics of an app platform that are important to different organizations. Efficiency, flexibility and security are all examples. However, these priorities are different from one organization to the next. And all are available if these four fundamental characteristics are in place.
Now let's add some color and texture with some examples you may be familiar with.
Examples
So far, we've talked about what app platforms do and what their important characteristics are. But, what does an app platform *consist of*? What are its parts? Today, it's safe to say that the discipline that implements app platforms - platform engineering - is in its infancy. As a result, the shape and form of app platforms is currently very diverse. An app platform can consist of a loose collection of tools with in a pipeline with some custom glue. It can be a packaged commercial offering that caters to a particular use case. Or it can be a custom software system purpose-built for the job.
Following are some examples of application platforms that are provided here to add color by way of familiar implementations in the world today.
Commercial Offerings
Vercel is a popular example of a commercial offering that provides developers of certain kinds of apps a way to get them deployed and into the hands of their users. The cloud providers offer their own incarnations of similar systems. Google Cloud Run is an example of this.
Bespoke Solutions
Many organizations put together a suite of tools to manage different parts of an app platform's functionality. For example, Terraform is commonly used to manage cloud infrastructure and managed services. It is often used in concert with tools like Ansible to manage deployment and configuration of apps on their remote servers. Often, companies will compile their own bespoke pipelines to pull all this together. Jenkins has long been used in this capacity.
GitOps
Arguably, the state of the art in "cloud native" application platforms is an approach called GitOps that uses open source implementations such as ArgoCD or Flux to help deliver containerized workloads to Kubernetes clusters. This is the modern version of Jenkins and follows a very similar pattern of implementation.
Shortcomings
Each of the above examples has critical issues related to the management concerns and fundamental characteristics of an app platform. This a large part of the reason that "application platform" has been so poorly defined. Vendors will often make a definition fit their product rather than making their product fit a good definition.
Threeport
Threeport is an open source application platform that meets all of the requirements of a good application platform. It takes a software engineering approach to software delivery and provides a system that is easy to get started with but has built-in extensibility so that you never outgrow its capabilities.
Qleet
Qleet can help your company implement and utilize Threeport. We pride ourselves on excellence in quality of service to your business. At Qleet, we earn your trust and your business rather than corner you into lock-in that you cannot escape if we fail to meet your expectations.
