What is PaaS (Platform as a Service)?
PaaS is one of the three classic service models in cloud computing. The provider makes a complete, managed platform available: physical servers, networking, operating system, runtime and often a database and development tools as well. You rent the platform and build your own applications on top of it. Everything that would normally require an operations department, patching, scaling, redundancy and monitoring of the underlying systems, is built into the service.
IaaS, PaaS and SaaS: who is responsible for what?
The three models differ in where the line of responsibility sits. With IaaS (Infrastructure as a Service), you rent virtual servers and networking but handle the operating system, updates and security yourself, a model reminiscent of classic cloud hosting. With PaaS, the provider also takes over the operating system and runtime, so your responsibility begins at the application and its data. With SaaS, you use a completely finished application such as Microsoft 365. The further towards SaaS you move, the less of your IT infrastructure you have to operate yourself, but the less you can customise too. In all models, however, data, access management and correct configuration remain your responsibility.
Typical use cases for PaaS
PaaS makes the most sense when you develop software yourselves or have it developed. Typical uses are web applications and APIs, where the platform handles scaling and certificates automatically, managed databases, where backup and patching are built in, and integration platforms that connect line-of-business systems, finance systems and cloud services with ready-made connectors. Test and development environments are also obvious candidates, because they can be created and torn down in minutes instead of requiring new servers.
Advantages and pitfalls
The big win is speed and focus: developers spend their time on the solution, not on server operations, and time-to-market drops noticeably. There are, however, two pitfalls you should know. The first is lock-in: the more of the platform's proprietary services your code uses, the harder it becomes to move to another provider later. The second is cost management: consumption-based billing is an advantage, but only if someone continuously cleans up unused resources and chooses the right service tiers. Both are best handled with a deliberate architecture from the start.
PaaS in practice: Azure App Service and Azure SQL
In Microsoft Azure, the most widely used PaaS services are App Service, which runs web applications and APIs without server administration, and Azure SQL Database, a managed SQL Server with built-in backup and high availability. Microsoft's own documentation provides a good overview in the introduction to App Service. For many Danish businesses, these two services are the natural first step away from self-operated application servers.
How MI Support IT can help
We advise on the choice between IaaS, PaaS and SaaS and help design, migrate and operate solutions on Microsoft Azure as part of our cloud and hosting services. Contact us if you are considering moving applications or databases to a managed platform.