In this ever-changing field of web development, keeping up with the most recent trends and technologies is important for web developers and designers to remain ahead of the curve. 

The 12 Factor App Methodology is a well-known one such methodology to know about, which is a set of best practices for designing, deploying, and distributing applications in the cloud platform and on-premise servers.

If you don’t follow these rules, the chances are high that you risk making the same mistakes as other senior engineers and waste your time trying to solve systematic difficulties. However, by employing this 12-factor practice, you’ll able to benefit from previous experience of previous professionals, which will save you time in the long run.

In this blog, we’ll delve into the details of the 12 Factor App Methodology to understand its effectiveness in creating robust software applications.

What’s the 12 Factor Application Methodology?

A collection of best practices called the 12 Factor App Methodology, arrives from the real-world experiences of developers at the cloud platform-as-a-service (PaaS) provider– Heroku, owned by Salesforce. 

Adam Wiggins, co-founder of Heroku along with other engineers drafted and presented the initial twelve factors around 2011 and since then, these guidelines have been widely used by developers and engineers around the world. 

These 12 different factors or recommendations help developers in creating a basic yet scalable web app or SaaS application.

  1. Codebase

Codebase refers to the entire collection of source code used to build a particular application or project.

The first factor, “Codebase,” emphasizes the importance of having a single codebase tracked by version control. This maintains consistency across App development and results in effective collaboration and fewer errors. 

Version control, also known as source control, is a system that records changes to a code file or set of files over time so that you can recall a specific version later on if needed. GitHub, GitLab, Bitbucket, and Mercurial are examples of version control systems for managing codebase.

So, one codebase tracked in version control, and many deploys. This means the same codebase is used for multiple deployments but in different stages –development, testing, and production.

  1. Dependencies

Most programming languages deliver support libraries through a packaging system. These libraries can be installed in two ways– 1. System-wide, known as site packages, or 2. Directly within the app’s directory– a method called bundling.

In contrast, a twelve-factor app does not assume that these site packages are already present. Besides, it emphasizes not just bundling but also strict isolation of the app’s execution environment from the host system, thereby ensuring consistency, reliability, and scalability across different deployment environments.

In simpler terms, a twelve-factor app is designed to be self-contained to prevent conflicts with other libraries on the host computer.

  1. Config

As the program as well as its setup must be completely self-contained according to our just above guideline, this means you should avoid keeping the configuration in the code. 

So, the 12-factor app saves the configuration in environment variables that may be easily changed during deployment. These variables allow you to update config values without affecting the rest of your code, and they eliminate the need to redeploy your program when particular config values change. 

Not only that but storing configurations as variables eliminates the possibility of configs being mistakenly checked into the repository.

  1. Backing Services

A supporting service is a collection of services on which your web application depends for network functionality and access. Datastores, SMTP services, caching systems, and queuing/messaging systems are a few names of the services available. 

In a 12-factor app, both local and third-party services are treated as connected resources in the code and are accessed using locator credentials contained in config or URLs. It implies that the app can switch between local and third-party services by just changing the resource handle, rather than having to change the code.

  1. Build, Release, Run

There are three phases in transforming a codebase into a successful deployment: Build– Converts a code repo into an executable bundle or Build, Release– Combines build with deployment’s current settings or configuration, and Run– Converts a code repo into an executable bundle or build that runs the app in the execution environment. 

Previously, changing the code during runtime was difficult due to a lack of a means to propagate changes to the build step.

However, these construction and run stages are separated in the Twelve-Factor App. The developer starts by putting the software under source control and figuring out what it needs. It’s also easier to mix the config information with the build for the release stage and get it ready for the run stage by separating it. 

Also, it’s worth noting that each release has a unique ID– release timestamp and incrementing version number because new releases are made regularly.

  1. Processes

The twelve-factor app is run as one or more processes in the run environment. It acts as a database for the data that is required to reside in the stateful backing service. 

The goal here is to make the process stateless and non-shareable. The process memory space can be used as a single transaction cache for a short period. Session state data is an appropriate choice for a data store that provides time expiry to meet this notion.

  1. Port Binding

A virtual network connection endpoint is referred to as a port. Ports allow an application or system to connect with other services through the internet with ease. 

Some network ports on your network firewall feature opening and shutting ports that regulate device access over the network. We bind ports to determine where and how a message will be transmitted and received, as the program cannot connect to the outside network without the required settings.

Web programs are sometimes run within a cloud container. The twelve-factor app, on the other hand, is self-contained and does not rely on runtime web server injections into the execution environment to build a web interface. It is unaffected by the additional program. 

So, the web app, which follows the twelve-factor app methodology, exports HTTP as a service and waits for requests originating from that port.

  1. Concurrency

The twelve-factor app is built, packaged, and deployed in such a way that the many of application’s components execute as separate and independent processes. This enables separate upscaling and downscaling of software components.

  1. Disposability

To support better scalability, quick deployment, and handling of failures, an app based on the twelve-factor app approach features disposable processes, i.e., processes that can start and stop at any time. 

However, the idea behind this notion is also that the app’s disposability should not bother or hinder the user and that it may be replaced by other components or restarted properly. By incorporating disposability into the software, it can clean up all used resources and gently shut down. It also guarantees the app is quickly restored.

  1. Dev/Prod Parity

Web Applications that are delivered to development and production must have parity, i.e. as similar as possible– according to the Twelve-factor app process. 

The disparity between the two deployments should be kept to a minimum. If there is a significant gap between development and production, unexpected compatibility concerns may arise. 

Besides, while developing twelve-factor software, the backend services used in both production and web development must also be the same to minimize any substantial downtime.

  1. Logs

Logs provide insight into the app’s activities. They are stored in a log file that is solely an output format in server-based setups. 

A twelve-factor program, on the other hand, should not be concerned with the routing or storage of its output stream, nor should it attempt to produce or manage logfiles. Rather, every running process should write its event stream to stand out without any buffering. 

Every process stream is monitored by the execution environment in production or staging deployments, combined with other streams, and directed to the final destination for long-term storage. You might also use several open-source log routers for this.

  1. Admin Processes

The application deployment includes several one-off processes– admin activities that are long-running and should execute in the same environment as the app’s normal long-run processes, such as performing one-off scripts and data migration.

The twelve-factor app recommends storing administrative operations in the code repository as a component of the application codebase. 

So, even though the Admin processes are separate, following the 12-factor approach, you must ship and execute the app code in the same environment and against the app’s config and base code to avoid synchronization issues i.e. interfere with the normal operation of the application. 

Also, to make it easier for off-script to run, each process type should use the same dependency isolation approach.


The twelve-factor app technique must be followed by every web developer who is constructing or planning to build a service application. 

Even though there are no one-size-fits-all solutions for web development, the twelve-factor guidelines offer the best practices and standards for developers and operations engineers to build, deploy, and maintain their apps on cloud and non-cloud platforms. 

So, it’s a fantastic plan that covers all of the necessary phases for launching a portable, scalable, and maintainable SaaS solution. Those who wish to create a SaaS product for their company should recruit developers who are not only familiar with programming languages but also with the twelve-factor app approach for cloud deployment.