The Twelve-Factor App

by Adam Wiggins

In the modern era, software is commonly delivered as a service: called web apps, or software-as-a-service. The twelve-factor app is a methodology for building software-as-a-service apps that:

- Use declarative formats for setup automation, to minimize time and cost for new developers joining the project;
- Have a clean contract with the underlying operating system, offering maximum portability between execution environments;
- Are suitable for deployment on modern cloud platforms, obviating the need for servers and systems administration;
- Minimize divergence between development and production, enabling continuous deployment for maximum agility;
- And can scale up without significant changes to tooling, architecture, or development practices.

The twelve-factor methodology can be applied to apps written in any programming language, and which use any combination of backing services (database, queue, memory cache, etc).

Genres: Programming, Technology, Software, Nonfiction, Computer Science, Technical, Architecture

39 pages, ebook

First published January 1, 2012

Reviews

[Apteris · Rating 5 out of 5]

Ten years is rightfully considered a long time in IT, so the fact that the 12 factors listed here are still very relevant today -- ten years after the book was published -- speaks highly of it.

[Justin Weiss · Rating 4 out of 5]

An industry-changing book you can read in about 15 minutes.

[Mateusz Hoffman · Rating 4 out of 5]

Easy to read book about Twelve-Factor app methodology - contains fundamental principles for modern application development, including configuration, application module separation, scaling, availability and many more.

Most of the information is probably well known for experienced developers but knowledge is as good as it is used in practice so I recommend reading this title even as a quick refreshment.

[Erick Corona · Rating 4 out of 5]

A quick read with some good tips to design service programs.

[Amr · Rating 4 out of 5]

Short, concise, and insightful.

Will be helpful if you are starting your career. If you have worked for couple of years in a proper software company or a team, the information might be redundant. Worth reading as a refresher anyway

[Marat Chardymov · Rating 4 out of 5]

12 generic principles of building modern web apps. Some of them could be seen as a novelty back in 2011, but nowadays this is industry standard(especially true for opinionated polished stacks like Rails), partly because in 2k18 we have such great tools as docker, dotenv, ansible, clouds are everywhere and libraries matured significantly. Must read for novice but experienced web developer likely won't find anything new.

[Matt Fewer · Rating 5 out of 5]

Short and sweet, but rich with insight. As a developer, I sometimes deal with 'imposter syndrome', where I feel I am not as knowledgable in some topic as the rest of my coworkers, or that my abilities fall short. This book reaffirmed my programming education of best practices. It's about time someone came out and showed us the best lexicon and practices in modern day web development. All done in a clear and easy to get through manner.

[Khaled Al-Ansari · Rating 4 out of 5]

I enjoyed reading this mini-book, it is simple and explain some of the common patterns seen to enhance application/service development under a well structured steps.

The main benefit of this book is how to organize app development using the methodology in the book, other than that experienced individuals won't find a lot in it.

[Vasya Rudas · Rating 5 out of 5]

This book describes real requirements to an application that meant to be a “microservice”. And is a best starting point for understanding is your application is ready to be contained in an Docker image and after that to be used in Kubernetes. The simple 12 chapters covers a lot of best DevOps practices that can simplify a CI/CD processes during development.

[Stanislav Skalický · Rating 4 out of 5]

kind of a cheat sheet regarding the designof a SaaS-like apps. In some points too brief though. To fully understand some points I had to study another sources. But after that I keep going back to this 12-factor app methodology.

[Shenyu · Rating 5 out of 5]

Surprisingly, methodologies introduced almost 5 years ago are still highly available and can be considered as an ideal standard in contemporary software engineering industry.

[Nathan Gavenski · Rating 4 out of 5]

it could have code examples

[Serdar · Rating 5 out of 5]

I read it every once in a while, and so far it's still up-to-date :)

[Alexander Bandukwala · Rating 5 out of 5]

Very short and easy read, so it's a must read for anyone working in webdev. Really founds the basis of modern app infrastructure.

[Hai Sam · Rating 5 out of 5]

Basic, short, interesting and cool.

[Hou · Rating 4 out of 5]

Not a silver bullet, but 12 sharp arrows.

[Luboš · Rating 5 out of 5]

I guess that the information from the book is already widely known, but still nice recap, short and available for free.

[Omelian Levkovych · Rating 5 out of 5]

nice pamflet

[Lorenzo Boccalon · Rating 4 out of 5]

Years of expertise condensed into a 30-minute long free online book. If paired with a case study, it would become exceptional!

[Surattikorn · Rating 5 out of 5]

Every software developer should read it because it is very important basic knowledge.

[Lucas Puskaric · Rating 4 out of 5]

There’s probably not much new here for most people nowadays, but it’s mostly evergreen.

[Orca the Whale · Rating 5 out of 5]

Short but essential.

[Usman Bashir · Rating 5 out of 5]

Very short, but concise introduction to best practices and patterns for architecting modern SaaS apps. Written by the people behind Heroku and based on their extensive experience deploying apps and observation of hundreds of thousands of deployed apps on the Heroku platform.

Because of its short length, it serves best as a list of guidelines. And, a jumping off point to keep researching and learning.

Though, it was last updated in 2012. It’s insights are still as relevant as when they were first written. Most notable, a web app built using the twelve-factor methodology fits right in at home with the hype for containerized web services these days, running in Docker or CoreOS.

TL;DR: Worth a read if you’re thinking about your web apps architecture. And, are not deeply familiar with Heroku or Docker.

[Aleš Roubíček · Rating 4 out of 5]

Krátká knížka, kterou přelousknete za cestu autobusem. Přesto obsahuje v hutné formě spoustu zajímavých tipů, jak psát snadno deployovatelné a managovatelné webové služby (SaaS).

I když kniha předpokládá, že budete deployovat na UNIX like systém, jistě se dají tyto praktiky aplikovat i do světa Windows. Osobně jsem spoustu z nich na Windows praktikoval.

Doporočuji k přečtení všem, i těm, co zrovna SaaS nepíší.

[Antonios Hadjigeorgalis · Rating 3 out of 5]

This book was an introduction to best practices in building web apps. The authors have witnessed 100's of thousands of apps in their work with Heroku. It was a quick read and for me gave an idea of what to think about in terms of the architecture of web apps.

[Johan]

Patterns for the architecture of a contemporary SaaS app, written by the guys from Heroku. Written concise and clean. Great read. Can be read/downloaded for free at http://www.12factor.net

[Sean · Rating 3 out of 5]

Some best practices to do with apps. A bit short, but some good pointers in here.

[Miloš · Rating 5 out of 5]

Concise, direct, well-argued bundle of best practices for web app development

[Cyber Killer · Rating 4 out of 5]

Not everything here is nice from a sysadmin PoV, but if all devs would learn to write apps like these, then I can as a compromise work with such apps.

[Shane Becker]

Real good. Could stand to be updated.