Term
PaaS
Platform as a service — the provider runs the servers and runtime while you deploy your own application.
Updated
What it means
PaaS rents the environment your application runs in: the operating system, the database server, the runtime and the deployment tooling are the provider’s to maintain. You supply and operate the application itself. It shares only the acronym with PAAS, the Bratislava parking system.
It sits exactly between IaaS and SaaS. With IaaS you administer the server; with SaaS you administer nothing. PaaS takes the infrastructure and leaves you free in your own code.
Responsibility in PaaS is split by layer. The provider answers for the security and availability of the platform; the customer answers for the application code, its data, its users and their access rights. A bug in the application or a leaked administrator password remains the company’s problem, not the platform’s.
How it works in practice
For a company with its own application or a bespoke online store it means faster deployment and less server maintenance than classic hosting or a machine of your own. Scaling for seasonal peaks becomes a setting rather than a purchase.
In the books it is a service billed monthly on usage - an operating cost. The budget should include egress traffic and instance counts, which become the largest line as you grow.
Where the application handles personal data of customers or staff, a data centre region inside the EU is chosen and a data processing agreement is concluded with the provider. Large providers include it in their terms of service, but someone has to find it and file it with the GDPR documentation.
What to watch out for
The price of the convenience is platform dependence: the more of its proprietary services you use, the more expensive leaving becomes. So keep boundaries at the API level and hold your data in a portable format.
PaaS bills are often inflated by forgotten environments: a test staging setup, a temporary database copy or an instance left over from a finished project. They run with no visitors and are billed every month, so it pays to set a spending alert and go through the list of resources once a quarter.
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