Crawl, Walk, Run
One of the key ways Google achieves good results with fewer testers than many companies is that we rarely attempt to ship a large set of features at once. In fact, the exact opposite is the goal: Build the core of a product and release it the moment it is useful to as large a crowd as feasible, and then get their feedback and iterate. This is what we did with Gmail, a product that kept its beta tag for four years. That tag was our warning to users that it was still being perfected. We removed the beta tag only when we reached our goal of 99.99 percent uptime for a real user’s email data. We did it again with Android producing the G1, a useful and well-reviewed product that then became much better and more fully featured with the Nexus line of phones that followed it. It’s important to note here that when customers are paying for early versions, they have to be functional enough to make them worth their while. Just because it is an early version doesn’t mean it has to be a poor product.
It’s not as cowboy a process as it might sound at first glance. In fact, in order to make it to what we call the beta channel release, a product must go through a number of other channels and prove its worth. For Chrome, a product I spent my first two years at Google working on, multiple channels were used depending on our confidence in the product’s quality and the extent of feedback we were looking for. The sequence looks something like this:
Canary Channel: This is used for daily builds we suspect aren’t fit for release. Like a canary in a coalmine, if a daily build fails to survive, then it is a sign our process has gotten chaotic and we need to re-examine our work. Canary Channel builds are only for the ultra-tolerant user running experiments and certainly not for someone depending on the application to get real work done. In general, only engineers (developer and testers) and managers working on the product pull builds from the canary channel.
- Dev Channel: This is what developers use for their day-to-day work. These are generally weekly builds that have sustained successful usage and passed some set of tests (we discuss this in subsequent chapters). All engineers on a product are required to pick up the Dev Channel build and use it for real work and for sustained testing. If a Dev Channel build isn’t suitable for real work, then back to the Canary channel it goes. This is not a happy situation and causes a great deal of re-evaluation by the engineering team.
- Test Channel: This is essentially the best build of the month in terms of the one that passes the most sustained testing and the one engineers trust the most for their work. The Test Channel build can be picked up by internal dogfood users and represents a candidate Beta Channel build given good sustained performance. At some point, a Test Channel build becomes stable enough to be used internally companywide and sometimes given to external collaborators and partners who would benefit from an early look at the product.
- Beta Channel or Release Channel: These builds are stable Test Channel builds that have survived internal usage and pass every quality bar the team sets. These are the first builds to get external exposure.
This crawl, walk, run approach gives us the chance to run tests and experiment on our applications early and obtain feedback from real human beings in addition to all the automation we run in each of these channels every day.