Update testing guide to reference test design

1 files changed, 15 insertions, 0 deletions

diff --git a/doc/development/testing_guide/best_practices.md b/doc/development/testing_guide/best_practices.md
index cfe0e6f70fc..7262c04d746 100644
--- a/doc/development/testing_guide/best_practices.md
+++ b/doc/development/testing_guide/best_practices.md
@@ -1,5 +1,20 @@
 # Testing best practices
 
+## Test Design
+
+Testing at GitLab is a first class citizen, not an afterthought. It's important we consider the design of our tests 
+as we do the design of our features. 
+
+When implementing a feature, we think about developing the right capabilities the right way, which helps us 
+narrow our scope to a manageable level. When implementing tests for a feature, we must think about developing 
+the right tests, but then cover _all_ the important ways the test may fail, which can quickly widen our scope to 
+a level that is difficult to manage.
+
+Test heuristics can help solve this problem. They concisely address many of the common ways bugs 
+manifest themselves within our code. When designing our tests, take time to review known test heuristics to inform 
+our test design. We can find some helpful heuristics documented in the Handbook in the 
+[Test Design](https://about.gitlab.com/handbook/engineering/quality/guidelines/test-engineering/test-design/) section.
+
 ## Test speed
 
 GitLab has a massive test suite that, without [parallelization], can take hours