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This is it, the first episode of my podcast! The new year gave me the push I needed to start shipping.
I launched this podcast to share ideas and practices that have helped me throughout my career. I write each episode to be short and informative so you can fit them in over a cup of coffee (or sometimes two). Think of Small Batches as a free form anthology on the wide world of software engineering and business.
Let's set the stage before we dive into today's topic. My goal as a software engineer is create systems that are easier to build, test, deploy, and operate in production. I achieve those goals through DevOps.
DevOps connects our work as engineers to business value. Exploring, internalizing, and implementing DevOps changed my career. I've spent the last few years reading and writing about DevOps, so there's no better way to launch this podcast than introducing DevOps.
For this, I turn two of the best books on the topic: The DevOps Handbook and Accelerate. Both are written by Gene Kim (you may also know him from The Phoenix Project and now the Unicorn Project) and other coauthors. The DevOps Handbooks introduces DevOps principles and their associated technical practices. Accelerate provides metrics to measure progress and evidence of DevOp's effectiveness. You need both to understand DevOps.
The DevOps Handbook introduces the "Three Ways of DevOps". They are: flow, feedback, and learning. Each build on the other to create a feedback loop between technology and business. Accelerate defines four metrics: lead time, deployment frequency, mean-time-to-resolve, and change failure rate. Here's how two fit together.
Flow, the first way of DevOps, establishes fast flow from development to production. Organizations achieve this goal by breaking work into smaller batches, preventing defects with continuous integration and automating deployments. These practices fall under the Continuous Delivery umbrella. Teams can measure their flow with two metrics: lead time and deployment frequency. Leads time is the time it takes to go from commit to production. Deployment frequency is simply how often deploys happen.
Feedback, the second way of DevOps, establishes right to left flow of telemetry across the value stream to ensure early detection and recovery or prevent subsequent regressions. The idea is to use production learnings to drive subsequent developments. Here's some examples: say you just shipped a new feature, how is engagement measured? Another: Are their metrics or logs that engineers can use to monitor system health? One more: do we know how long are builds are taking? Teams can measure the second way with the well known mean-time-to-resolve (or MTTR) metric.
Learning, the third way of DevOps, enables a high-trust culture focused around scientific experimentation and learning. The idea is that once work is shipping out to production quickly and the telemetry is in place to across the value stream, then teams should improve their processes through scientific experimentation. The principal of flow enables teams to quickly ship new business ideas or process improvements. The principal of feedback ensures teams have the information to empirically validate their ideas. Organizations apply this principle through activities such as blameless postmortems and A/B tests. Team can measure the third way by tracking their change failure rate. That is the percentage of changes that result in degraded service or require a follow up action like a patch or rollback. Although I offer a different interpretation. I think of it as the percentage of changes that did not deliver the expected results–but that's a topic for a future episode.
I have much more to say on all these topics but I'll leave that for future episodes. Let's recap: Apply continuous delivery for fast flow from development to production; add telemetry across your process and use it to drive future decisions, then strive to improve both those processes. Measure your progress with lead time, deployment frequency, MTTR, and change failure rate.
Your trajectory should be to decrease lead times, increase deployment frequency, decrease MTTR, and decrease change failure rate. Or in other words, as you improve velocity then stability comes along for the ride.
Alright, that's wrap on this episode. Go to smallbatches.fm for show notes, a transcript, and links for my review and analysis on DevOps Handbook and Accelerate. Also subscribe to this podcast to receive future episodes.
Until the next one, good luck out there and happy shipping!