Glossary

Continuous integration is the practice of merging the code of all developers on a project and testing for conflicts continuously, as changes are made.

Smoke tests are a type of regression test which ensure that your most important, critical functional flows work. These tests should not encompass your entire testing suite, rather they are a subset of tests that cover your top prioritized user flows. These are usually end-to-end tests that are executed in…

In any complex system, failure is inevitable. Chaos engineering, or chaos testing, embraces this reality, allowing you to introduce failures in a controlled way.

Simpson’s Paradox, otherwise known as the Yule-Simpson Effect, is a reversal paradox where the correlation found in each of several groups either disappears or even reverses when the groups are combined. It’s relevant in the context of many non-experimental studies, including A/B tests. Examples of the Paradox One classic example…

A type I error (or type 1 error), also called a false positive, is a type of statistical error where the test wrongly gives a positive result, when a perfect test would report a negative. It is one of four possible results from a hypothesis test. What is Hypothesis Testing?…

A type II error (type 2 error) is one of two types of statistical errors that can result from a hypothesis test (the other being a type I error). Technically speaking, a type II error occurs when a false null hypothesis is accepted, also known as a false negative. In…

CI/CD is the acronym in software development for the combination of continuous integration (CI) and continuous delivery (CD). It can also be expanded to include continuous deployment, but to avoid confusion in this article, we’ll be using CD to refer to continuous delivery. It’s an extremely useful agile process for…

Trunk-based development (TBD) is a branching model for software development where developers merge every new feature, bug fix, or other code change to one central branch in the version control system. This branch is called “trunk”, “mainline”, or in Git, the “master branch”. Trunk-based development enables continuous integration – and,…

Feature flag management is the process of, well, managing feature flags. While feature flags are extremely useful for many purposes, they require an organized process to manage. In what specific ways, we’ll discuss shortly. There are two main types of feature flag management systems: those which are built in-house and…

False positive rate (FPR) is a measure of accuracy for a test: be it a medical diagnostic test, a machine learning model, or something else. In technical terms, the false positive rate is defined as the probability of falsely rejecting the null hypothesis. False Positive Definition Imagine you have an…