diff --git a/PRINCIPLES.md b/PRINCIPLES.md
index fab15ff..a83cf32 100644
--- a/PRINCIPLES.md
+++ b/PRINCIPLES.md
@@ -254,3 +254,4 @@ See also [Calm programming / Slow programming](README.md#calm-programming--slow-
 * It also means that when building systems, you should not assume that operators will do things correctly. Expect failure from people. Try to think about tools you can give them to undo their mistakes, because they will happen sooner or later. Have some dread. Be understanding. Know things won't be perfect. [source](https://ferd.ca/lessons-learned-while-working-on-large-scale-server-software.html)
 * Study your tools, see how you work, understand how you can improve it. Don't rush. Before you run, you have to learn to walk. 
 * Wait before jumping on every opportunity/request/problem. Don’t touch it / don’t act too soon
+* Use right tools for the job (email != todo list, PR and commits != code documentation, Jenkins != long term storage for releases/versions/build info/state of quality of your code)