# Scale content-driven web app backends

Scaling refers to increasing (or decreasing) the capacity of resources available
to the backend to improve its performance or availability. While scaling is
inherent to the architecture, design, and implementation of your backend,
several vital aspects must be considered.

Performance here refers to how quickly the web application can respond to a
request; this includes latency, speed, throughput, and resource utilization.

## Vertical scaling

Vertical scaling refers to increasing the resources on a server. This may mean
replacing a central application server with a more powerful machine for a
server-based architecture. For serverless, microservices, or cloud-based
architectures, this may refer to upgrading the allocated resources, such as
increasing the available memory or selecting a higher-tier virtual machine.

## Horizontal scaling

Horizontal scaling refers to the addition of more servers and parallel
resources. The underlying architecture and the application must be optimized to
handle this type of scaling. For example, additional load balancing may be
needed to distribute requests in a server-based architecture. For a serverless
architecture in a cloud environment, such as [Cloud
Functions](https://cloud.google.com/functions), this type of scaling may be
handled transparently without any additional configuration.

## Regional scaling and distribution

Regional scaling refers to distributing services across multiple geographic
regions. Distributing your services, or moving your services closer to users,
can reduce latency and improve the overall performance of your application.

Consider regional distribution and diversity as part of your architecture,
especially if you are not using a cloud provider that handles this
transparently, such as in a cloud-based serverless architecture. Consider how
[data storage](https://developers.google.com/solutions/content-driven/data-storage) in your application may
be impacted by regional distribution, especially around data consistency.

When processing and storing data at a global scale, be aware of any regulatory
requirements or legislation that applies to your system, especially around data
processing and [data
storage](https://developers.google.com/solutions/content-driven/data-storage/regulatory-compliance).