What is the difference between alpha vs beta apps, and nightly vs production builds? With so many names and varying definitions across industries, identifying the purpose and process of mobile app builds can get confusing.
A build is what you get when you compile your source code along with any third-party libraries and package it into an executable format like .apk, including unit and integration testing. You will use this process throughout the app development lifecycle and builds will differ in their usability and stability depending on their position in the development cycle.
Nowadays, with the increased adoption of “continuous integration”, an automated build can be made every time a new commit is made. By integrating frequently, it becomes much easier to identify any commit that might “break” the build. To be able to differentiate between builds, every build is given a label or version number to identify it.
One of the oldest build tools on the scene, gmake is used to build apps for Mac or Linux environments.
XCodeBuild is Apple’s build tool included with their IDE, Xcode. It can be called from the command line and is excellent for building apps for Apple platforms like macOS and iOS.
Apache developed ANT to introduce a build tool optimized for Java. ANT uses XML files to describe the build process which can be cumbersome. It is now being replaced with newer tools that use easier methods of describing the build process.
Another tool by Apache, Maven is a build tool that relies on convention to describe the build process. This gets rid of the need to write XML files, simplifying the process. Maven is a very popular tool and is considered the defacto tool for Java development.
Gradle is an open-source build tool that was released in 2012 and has been rapidly gaining in popularity since. It combines Maven conventions while exchanging Ant’s XML files with a Groovy-based Domain Specific Language.
To ensure all builds are reproducible and avoid “works on my machine” scenarios, all builds are created on a dedicated server. You can trigger the builds manually or schedule them to run automatically at certain intervals. If you practice continuous integration, CI/CD tools trigger a build every time a change to the source code is detected. This also serves to avoid blocking your work while you wait for the build to be done.
Before looking at the difference between alpha and beta, it is important to distinguish between the alpha/beta phase and an alpha/beta build. Alpha and beta are distinct phases of the development lifecycle defined by the development progress of the app. They are characterized by different stability, usability, and feature-completion degrees.
Throughout the alpha/beta phase, developers will be adding new code to the app and making new builds to test it. In other words, the alpha and beta phases consist of many iterative alpha and beta builds. Not all nightly builds made throughout the alpha/beta phase are always made available to testers, only select builds deemed fairly stable are chosen for testing.
The first alpha build is the first working version of your app, which doesn’t always have the full features implemented. It is often too buggy to be usable, but contains, at a minimum, the core functions of the app ready for testing.
Developers will add any missing features and, along with QC, focus on finding, tracking, and squashing as many bugs as they can find. When the app becomes “feature complete” and no major crashes or bugs remain, the alpha phase is considered complete and the final build then becomes the first beta version.
Traditionally, you would conduct alpha tests internally without involving anyone outside the development cycle, however, using external testers or even end-users for the alpha phase is not unheard of. In fact, it has recently become relatively more popular among smaller development teams that don’t have a dedicated QC team.
The beta build is the version marking the completion of the app’s development. Traditionally at this stage, no new features are added and focus becomes on improving the quality, usability, and overall experience. Beta is the first build available to users outside development and can still suffer from bugs and stability issues. However, it should not have any major issues and is considered a full-featured, usable version.
Beta testing programs can either be closed with access restricted to invited members or open where anyone can participate. Either way, the app is tested in “real world” environments with “real world” scenarios by external testers/users. Due to the greater diversity of device environments and use patterns, this helps uncover many bugs that slipped through earlier test phases. The developers will then use the submitted bug and crash reports to pinpoint and fix all the reported defects and iterate on the builds until the application is ready for release.
Since beta testing is the first time users get to try the app, it is the first opportunity for validation. Currently, most beta builds utilize tools to allow in-app communication, in-app surveys, track in-app behavior, and automate bug and crash reporting to maximize the feedback they receive about functionality, usability, and feature requests. If feedback uncovers major flaws in features or functionality, the team will address them before release; otherwise, the feedback is implemented in the next iteration.
Honoring the principle of “integrate early, integrate often”, as the name suggests, the nightly build changes every night. It is an automated build that is made at the end of the day by incorporating all the changes made during that day. They are not restricted to any stage of the development lifecycle and are used throughout the cycle, i.e. during alpha/beta testing (or any other stage of development). A nightly build is produced every day reflecting any changes to the code.
Nightly builds are typically not accessible to anyone outside the development lifecycle but are sometimes shared with select external testers. They are on “the bleeding edge” of development and can be buggy and unstable. A nightly build towards the end of a beta cycle should be stable while one at the beginning of the alpha test is not usable.
When you iterate enough on the beta build to be stable and no new bugs or feedback is being received, QA will mark it as a “release candidate” (also called “going silver”). At this point, developers will not make any changes to the app except for minor code fixes and improvements to the documentation. When these final touches are complete, the build goes into production and distribution to the end-users. This is also known as “general availability” or “gold candidate”.