What Is the Difference Between PaaS And FaaS?

Serverless architectures are adaptable models of cloud deployment where software developers hand over their scaling and maintenance to a provider, so that every application can run with the optimal resources when the occasion demands it. FaaS—Function as a Service—and PaaS—Platform as a Service—are two types of cloud computing models that can be eye-opening to developers interested in serverless architecture, because each can handle complicated aspects—including speed to deploy and the effort required to supervise—of running software on the cloud.

Their proximity to serverless—and their convenience—has made both models staples in the cloud. The FaaS market size is expected to grow to almost $45 billion in the next five years. Predictions for PaaS are even higher . These two acronyms are very much pushing the cloud up the ladder.

To understand the difference between FaaS and PaaS, we’ll explain each technology so every developer, solopreneur or tech enthusiast can understand each, their differences, and what makes it more advantageous for their application.

How FaaS and PaaS relate to the other cloud computing service models

Before cloud computing, businesses had to manage their own IT systems in thick mainframe systems—on-premises. On top of physical servers, organisations run virtual machines to segment them. On top of that, they had to take care of the computer’s operating system. Then came the invisible layer—the runtime environment. Finally, at the very top was the application, the company could deploy the actual service someone could use, e.g. like an enterprise application to manage their expenses. It took a lot of money to maintain this whole system, and fixing problems could take weeks. This is probably why IT reps at companies are so well-versed with infrastructure practices, even if other staff members expected them to just code in Java.

Source: IBM Technology

Legend has it that when Amazon bought so many servers for their business, they mulled over what to do with the excess processing power. And with that idle CPU capacity, they launched AWS and the cloud so that third parties could also use it. Along with other vendors trying to do the same thing, the early 2000s saw the rise of cloud computing with Infrastructure-as-a-Service (IaaS). IaaS outsources the foundation (hardware) and pre-fabricated enclosures (virtualisation) of the IT system to a third party. Companies access those servers through the internet—meaning they’re in “the cloud.” Since then, businesses can rent computing power, storage, and networking from cloud providers like AWS or Azure instead of managing their own servers. This is much more economical in the short term and allows for faster setup, taking hours or even minutes compared to weeks.

From this model, plenty of consumers—not even developers—are familiar with SaaS. Software-as-a-service (SaaS) takes abstraction to the next level by delivering the entire application over the internet. Consumers can access a PDF converter without deploying a single instance of an app or without any downloads. SaaS, as an offering, exists thanks to models like IaaS, but there are more recent developments in cloud deployment.

One is Platform-as-a-Service (PaaS). PaaS takes the abstraction level a step further than IaaS by offering a pre-built platform with the operating system and runtime environment already in place. While companies are still running at least one server with this model, developers are just worried about building their applications. The time to provision and get the application out the door is much shorter, bringing deployment down to minutes or even seconds.

Function-as-a-Service (FaaS) appears to be the next step in cloud computing’s rise to prominence. Here, the abstraction reaches the application layer itself. Developers only work on specific parts of an app, like uploading an image, and run them on the FaaS environment. The cloud provider handles everything else, including servers and runtime environment. So when a heap of consumers try to use the service, a good FaaS setup will automatically scale up so that the application doesn’t go down.

PaaS and FaaS are two types of serverless computing, especially from a developer’s perspective. In both PaaS and FaaS architectures, the server is hosted in the cloud, which means it’s someone else’s server that’s being rented. So, while neither completely eliminates servers entirely, they both move towards a “serverless” approach by abstracting server management tasks from developers.

Still, the two models differ in the level of abstraction and how the servers are managed. Here’s a brief summary:

What is FaaS? Function as a Service explained

FaaS stands for Function-as-a-Service. FaaS is a subset of serverless as it operates in the cloud, meaning developers don’t need a physical server to host their app. FaaS platforms not only manage servers, but also scale, provision, allocate resources, and set up infrastructure. The complete abstraction of server management frees developers to focus just on writing the code that makes the app work.

FaaS lets you write and deploy independent functions—microservices —triggered by specific events within your application. These events can include user actions like login or sending a notification. These functions are mini-programmes you can easily add, remove or update without affecting the entire application. We’ll talk about the integration of FaaS with microservice architectures later, but for now, it’s important to understand that FaaS simplifies development by letting developers focus on building specific functionalities without the burden of server management.

Source: Oreilly

How does FaaS work?

Traditionally, applications were built as monolithic entities, where all functions were bundled together. This meant developers needed to manage a complex codebase and handle server infrastructure all at the same time. FaaS breaks this down by using microservices—a service that’s meant to support only a specific type of application or task.

This includes tasks that you could do every day, like sending a notification via email. The difference with an API is, among other things, that a microservice is exceptionally specific and can be isolated or updated on its own without affecting a “monolithic” app.’’

Source: IBM Technology

Very simple example of FaaS

A user uploads an image and presses “submit” on a mobile app. This action triggers an event within the FaaS architecture. This event is then routed to the appropriate microservice. In this case, an image processing microservice would be specifically triggered.

Source: blog.alexellis

In FaaS, these microservices become event-driven functions. These functions are independent pieces of code that execute only when triggered by specific events. This can include user actions like clicking a button, changes within a database, or incoming API calls.

Unlike traditional applications that run constantly, FaaS functions operate on a pay-per-use basis, which makes them cheaper to run.

For instance, consider a new bank building their entire user experience out of already-existing microservices. They might choose to acquire login functionalities from one vendor and the onboarding experience from others. These vendors sell their products as APIs.

Typically, deploying these services would require extensive configuration on their own servers. It could even mean developing the whole thing from scratch (especially if the bank has some legacy infrastructure). However, FaaS offers a faster approach. Using pre-built microservices in a FaaS environment automatically takes care of infrastructure provisioning and scaling, so the bank can focus on building their user experience and get to market faster.

Source: IBM Technology

What are FaaS model’s pros and cons?

Now that we have explained what FaaS is, let’s look at its pros and cons for a developer wanting to scale up their applications fast.

Advantages of FaaS

FaaS makes app development much quicker by reducing the need to set up and take care of servers manually. This frees developers to devote themselves entirely to coding. Deployments also become easily accomplished with FaaS since the stack is already there waiting for your app to run.

FaaS has a significant speed advantage in app development… but precisely because it’s so good for deploying. Unlike SaaS and PaaS, where you still manage some infrastructure, FaaS completely abstracts away server setup and maintenance. This frees developers to devote themselves entirely to coding. FaaS makes deployments easy because the stack is already set up and waiting for your app to run.

If the platform is up-to-date with what developers need, then a good FaaS lets developers write code in any language they like. Some platforms even already offer a set of APIs developers can build with.

FaaS architecture is built for scaling. FaaS platforms automatically scale resources based on demand, which makes it possible for your application to handle sudden spikes in traffic safely without manual intervention.

FaaS platforms save money too. You only pay for the compute power your functions actually use. Pay-per-use models eliminate the cost of idle server capacity with a pay-per-use model.

Disadvantages of FaaS

While FaaS providers handle servers, security, and databases, this can make it hard for developers to customise those aspects. Debugging can also become more challenging due to reduced system visibility, unless there’s a built-in feature to cut down errors, like a typesafe model.

Additionally, unless the vendor has a niche understanding of how its community deploys apps, choosing FaaS often ties you to a specific vendor's platform. Switching providers later can be disruptive, and it may even require code modifications to function within the new environment.

Example of a FaaS service: How developers can scale up with FaaS

For developers and businesses that prioritise speed and agility, FaaS offers a adequate solution. Small startups can deploy backend functions for their mobile apps without server infrastructure concerns. DevOps teams can leverage FaaS to automate tasks and build highly scalable applications. Hobbyists can experiment and deploy code for personal projects with ease. In all these cases, the value of FaaS lies in its long-term benefits, even if the best benefits seem like the short-term ones.

Namely, reduced costs by only paying for used resources and automatic scaling to handle traffic spikes—that’s what developers will be forgetting about with FaaS.

With a FaaS framework, a developer can build up an enterprise application to request time off at a company. Then, by picking out each microservice, they can choose if the notification method for their coworkers will be push notifications or an SMS message. If the SMS provider suddenly changes their API, only that microservice will break down. The other services will keep on running.

Source: Genezio

Should you consider FaaS?

FaaS is best for building applications with microservice architectures, where each function performs a single, isolated task. But if your project demands a monolithic architecture or frequent function interaction, FaaS might not be the very best choice. Even without FaaS, the cloud offers solutions. PaaS (Platform as a Service), for example, offers another option to move some application functions to the cloud.

Source: wearecommunity.io

What is PaaS? Platform as a Service Explained

PaaS stands for Platform-as-a-Service. It is a cloud computing model that can be used to develop and deploy applications. The PaaS provider takes care of everything, from servers and networks to storage, operating system software, databases, and development tools. In a nutshell, it provides developers with a virtualised platform that includes everything necessary to build, run, and manage applications.

PaaS is related to FaaS. It lets developers focus on their applications instead of managing and maintaining the infrastructure. However, when it comes to scaling and cost, the models differ. PaaS applications usually require manual scaling, while FaaS scales automatically based on demand. PaaS also offers development tools and frameworks, which FaaS doesn’t as much. In addition, PaaS billing is typically based on a fixed fee or pay-as-you-go model, while FaaS charges per function execution time.

How Does PaaS Work?

Developers access a cloud-hosted platform equipped with all the necessary tools—from development frameworks to testing environments.

Its underlying strength lies in the three core components of a PaaS solution: infrastructure, software, and a user interface. The infrastructure, stored in the cloud, provides the foundation—operating systems, storage, the DB, everything. Developers use the software component, also accessible via the GUI, to build, deploy, and manage applications.

With PaaS, the cloud provider takes care of the heavy lifting of cloud infrastructure while developers keep control over the applications and data. PaaS vendors typically offer plugins that make integrations more or less easy than what plain coding would require.

Source: spiceworks

PaaS pros and cons

Here are some advantages and disadvantages of using PaaS for building applications, especially for a business that needs to offer quick software applications to an unpredictable market:

Advantages of PaaS

PaaS simplifies the entire development lifecycle. Building, testing, and deployment can all be managed within the same environment. PaaS eliminates the need to purchase and maintain your own hardware and software, reducing overhead.

Unlike FaaS where functions scale automatically, PaaS usually requires manual configuration adjustments. But PaaS lets developers use more resources independently, like storage, compute power, or memory. This makes PaaS a good choice for applications with predictable scaling needs, particularly those of moderate size.

PaaS platforms offer access to a set of resources that some organisations, especially incipient startups, might not even have. This gives developers and even non-technical people the freedom to experiment with new technologies without significant upfront costs, and that made them popular.

Disadvantages of PaaS

PaaS can create lock-in, making it difficult to switch providers later due to reliance on specific tools and platform architecture. Migrating applications may require significant code rewrites. PaaS may require more work than FaaS, which is not good for applications that need to grow quickly.

Source: chsakell

Example of a PaaS service: How PaaS can adapt to a new market

Heroku, a solution that probably runs on an AWS server, used to be a prototypical case of a PaaS service. It became very popular even among the non-technical crowd because it allowed non-developers who had a Node.js solution to get it running with a URL in their environment.

But Heroku fell from grace when it removed its free plans, with some commentators proclaiming it dead. What could help it revive its allure would be getting an elastic, easy-to-scale plan that could allow founders, entrepreneurs, and developers to lay back and not lose their time on DevOps… this is essentially what Genezio offers. Genezio goes beyond traditional PaaS platforms by letting you place your critical business logic in a secure backend environment. Unlike other PaaS offerings, Genezio doesn’t require you to rewrite your existing code or migrate to a specific framework. It collects everything that made PaaS popular in the first place and offers it along with developer-friendly serverless models. The market for a PaaS could bounce back if providers add scalability, reliability, and affordability to the classical offering, and Genezio is addressing those features with its product.

FaaS vs PaaS: The Difference for Developers

Both FaaS and PaaS are cloud models that allow developers to ship applications quickly without significant overhead. FaaS is growing rapidly, in tune with serverless platforms. This model is great for building microservice architectures where independent pieces of code can be developed and deployed quickly. It offers automatic scaling and pay-per-use pricing.

On the other hand, PaaS is less ready-made. It comes with a good bunch of frameworks and tools, ideal for applications with predictable scaling needs and moderate size. While PaaS provides more control over resources, it might require manual scaling, and switching providers can be difficult—just ask around your colleagues, and they’ll confirm they’re staying with a certain provider or the other just because they deployed there in the first place.

So, choosing between FaaS and PaaS depends on what your project requires and what’s most important to you or your business. They both let you build apps differently, making the decision a trade-off: control for customisation, flexibility for adapting to changes, and cost for resources.

Deploy serverless with a PaaS or FaaS niche partner

Offering end-users a SaaS—like an enterprise application or a PDF converter—is easier with a PaaS or FaaS provider that can scale with typesafe code from the get-go.

Both models serve different business and project needs. In any case, a niche, serverless provider like Genezio is the quickest way to get onto each tech path. Genezio can help you set up the right PaaS or FaaS solution for your current and future business needs and make sure it’s safe to use and as easy as possible to run.

Genezio offers a true pay-as-you-go serverless model with typesafe methods, so that users can focus on running their business or making sure their solution is better than the competition. And that’s precisely what investors and users will demand, but crashes and bugs won’t allow doing. Sign up now to try the platform and start deploying for free. It only takes a few clicks to get started building your serverless application, and you can build an unlimited number of projects with the Hobby account.

To learn more about the advantages of FaaS, typesafe serverless platforms with unlimited builds, visit Genezio.com .