diff --git a/TODO b/TODO
index 36ca8b7..8caef68 100644
--- a/TODO
+++ b/TODO
@@ -52,3 +52,8 @@ Another example:
 	!1:a()!1:a(?1:a?1:a)!1:a(?1:a?1:a)?1:a
 is equivalent to
 	((()())(()()))
+
+
+"Having metrics around as many things as possible really helped us
+ identify a difficult problem to diagnose."
+  -- https://github.com/blog/767-recent-services-interruptions