Ivan CernjaInternal Developer Platform vs PaaS: What's the Difference
A PaaS is a runtime you deploy to; an IDP is a self-service layer over infrastructure you own. Where they differ on control, ownership, and lock-in, and when each fits.
When Heroku ended its free tier in late 2022, a wave of teams that had run side projects and early products on it for years had to decide where to go. Some moved to newer managed runtimes like Render, Railway, and Fly. Others, especially the ones that had grown past a handful of services, used the moment to move onto their own AWS or GCP account and build a paved path for their engineers on top of it. Those two responses map onto the two things people mean when they compare an internal developer platform with a platform-as-a-service, and the choice between them turns on how much of the infrastructure you want to own.
A PaaS and an IDP sit at different layers of the stack, which is why they are easy to confuse and easy to conflate. A PaaS is a runtime you deploy to; an internal developer platform is a self-service layer over infrastructure your organization runs. The clearest way to see the difference is to put them side by side.
A PaaS is a managed runtime owned by the vendor that you deploy code to. An internal developer platform is a self-service layer your team owns, sitting over infrastructure in your own cloud account.
What a PaaS is
A platform-as-a-service is a managed runtime. You give the provider your code, sometimes a small config file, and it runs the app on servers it owns, scales, and keeps hidden from you. Heroku set the shape with git push heroku, and Render, Railway, and Fly.io carry it forward, as do the managed application services inside the big clouds. The value is that there is no infrastructure to operate. You do not touch a load balancer, a VM, or a Kubernetes manifest, and for a small team that is a large amount of work removed.
The cost of that convenience shows up in two places. You run on the provider's runtime and describe your app in the provider's terms, so moving off later means re-platforming onto something else. And the managed layer carries a pricing premium that grows with usage, which is why teams that scale on a PaaS often reach a point where the monthly bill makes their own cloud account look cheap. For more on the model and its tradeoffs, see what a PaaS is.
What an internal developer platform is
An internal developer platform is the self-service layer a company builds or adopts so its engineers can ship without filing tickets or learning every cloud primitive. It sits on top of infrastructure the organization already runs, usually its own cloud account, and gives engineers a paved path: templates to scaffold a new service, a catalog of what exists, environments they can spin up, and a deploy pipeline that follows the same rules every time. The infrastructure stays owned by the company; the platform makes it approachable.
That layer is assembled from a few kinds of tools, and they are worth keeping distinct. Developer portals like Backstage, Port, and Cortex give the catalog, scorecards, and templates that sit in front of infrastructure. Orchestrators like Humanitec generate and wire up environments from a spec. And code-first backend platforms produce the platform experience out of how the application itself is written, rather than as a portal bolted on beside it. The longer treatment is in the internal developer platform guide and the survey of platform engineering tools.
IDP vs PaaS at a glance
| Dimension | PaaS | Internal developer platform |
|---|---|---|
| What it is | A managed runtime you deploy to | A self-service layer over infrastructure you run |
| Who owns the infrastructure | The provider | Your organization |
| Where code runs | The provider's servers | Your own cloud account, usually |
| Control over the stack | Low, abstracted away | High, you set the defaults |
| Setup effort | Push and go | You build or adopt the layer |
| Lock-in | Tied to the runtime and its app model | Tied to your own cloud, lower switching cost |
| Cost shape | Convenience premium, grows with usage | Cloud bill plus the cost of running the platform |
| Best fit | Early products, small teams, prototypes | Many services and engineers, own-cloud requirements |
| Examples | Heroku, Render, Railway, Fly.io | Backstage, Port, Cortex, Humanitec |
Where they overlap
The line blurs because both aim at the same outcome for the person shipping code, a short path from a commit to a running service with the infrastructure handled. A small team on a PaaS gets that path out of the box, which is why a PaaS is sometimes described as an IDP you did not have to build. The difference is ownership. On a PaaS the provider owns and hides the infrastructure, so you accept its runtime and its pricing. With an IDP the infrastructure is yours and the platform layer is what makes it self-service.
Some setups sit in the middle. A company can run a thin internal platform whose runtime underneath is still a PaaS, keeping the paved path while renting the servers. And a growing PaaS user often reaches the point where the bill and the control limits push them onto their own cloud, at which point the layer they build is a backend developer platform of their own.
When each one fits
Reach for a PaaS when you want to ship without operating anything and you can accept the runtime and the pricing. It fits a prototype, an early product, or a small team where the hours saved matter more than the control given up, and it stays a reasonable choice well past the first launch. The reason to leave is usually concrete: the bill outgrows what the same workload costs on your own cloud, or a compliance or data-residency requirement means the infrastructure has to live in your account.
Build or adopt an internal developer platform once you have enough services and engineers that a shared paved path pays for itself, or once you need the infrastructure in your own cloud. The work is real, since the platform layer is something you own and maintain, and the how-to guide on building one covers what that involves. The upside is that engineers get PaaS-like self-service over infrastructure you control, without the runtime lock-in or the convenience premium.
Where Encore fits
Encore spans the two categories in a specific way, which is why it is a useful reference point in this comparison rather than a drop-in for either side. It is an open-source backend framework and a cloud platform: you declare infrastructure like Postgres, Pub/Sub, cron, and object storage as typed objects in your application code, services call each other as type-checked functions, and distributed tracing is built in. The platform experience, environments, preview environments, CI/CD, a service catalog, and an architecture diagram, comes out of how the app is written.
The part that touches this comparison is where the code runs. A PaaS runs your app on the provider's servers; Encore provisions into your own AWS or GCP account with sensible defaults you can adjust in the dashboard, so the workflow feels close to a PaaS while the infrastructure stays yours. It differs from a developer portal like Backstage or Port too, which catalog and template infrastructure you provision separately, because here the catalog and diagram are generated from the code rather than maintained alongside it. That makes it a code-first backend platform, not a portal and not a shared runtime, and encore build docker exports a standard image if you want to run it elsewhere. It also integrates with existing Terraform by exposing provisioned resources as data sources.
Related reading
Frequently asked questions
What is the difference between an internal developer platform and a PaaS?
A PaaS is a managed runtime you deploy code to, like Heroku or Render, where the provider owns the servers and abstracts them away. An internal developer platform is a self-service layer your own team builds or adopts on top of infrastructure you run, usually your own cloud account. The PaaS trades control for convenience; the IDP keeps the control and adds the convenience on top.
Is Heroku a PaaS or an internal developer platform?
Heroku is a PaaS. You push code and it runs on Heroku's managed dynos, with the underlying servers, scaling, and networking handled for you and hidden from you. An internal developer platform is something a company assembles for its own engineers, typically over its own cloud account, so the team keeps ownership of the infrastructure. Some teams use Heroku as the runtime underneath a thin internal platform, but Heroku itself is the runtime, not the platform layer.
When should you use a PaaS instead of building an internal developer platform?
Use a PaaS when you want to ship without operating infrastructure and you can live with its runtime and pricing. It fits early-stage products, small teams, and prototypes, where the time saved outweighs the loss of control. Building an internal developer platform makes sense once you have enough services and engineers that a shared paved path pays for itself, or once compliance and cost push you onto your own cloud account.
Do internal developer platforms replace PaaS?
Not exactly, because they solve different problems. A PaaS gives you a place to run code with no infrastructure to manage. An IDP gives your engineers a consistent self-service path across infrastructure your organization already owns. A team can outgrow a PaaS and build an IDP over their own cloud, and some platforms sit between the two by giving a PaaS-like workflow while provisioning into your account.
What are examples of PaaS and internal developer platform tools?
Common PaaS options include Heroku, Render, Railway, and Fly.io, along with the managed application services from AWS, GCP, and Azure. On the IDP side, developer portals like Backstage, Port, and Cortex give a service catalog and templates, while orchestrators like Humanitec wire up environments. Code-first platforms take a different shape, giving a platform workflow that comes out of how the application is written.
Does a PaaS lock you in?
A PaaS ties you to its runtime and its way of describing an app, so moving off it usually means re-platforming, and its managed convenience comes at a pricing premium as you scale. That lock-in is often an acceptable trade early on. Approaches that deploy into your own cloud account keep the underlying resources yours, which lowers the switching cost but leaves you owning more of the operation.
Automated infrastructure for humans and agents
Let agents build and validate features with real infrastructure in the dev loop. Encore automatically provisions infrastructure, from local dev to production in your cloud on AWS/GCP.