On the Care and Feeding of Feedback CyclesElisabeth HendricksonPivotal@testobsessed

DevOps Enterprise 2014 (#DOES14)

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 1

Who Am I?

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 2

What's Feedback?

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 3

Feedback Loops

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 4

What Do We Need Feedback On?

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 5

Feedback Latency

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 6

A Traditional Long Feedback Cycle(and why no one does this anymore)

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 7

Latency, Speculation, and Risk

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 8

Latency, Speculation, and Risk

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 9

Latency, Speculation, and Risk

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 10

Latency, Speculation, and Risk

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 11

Empirical Evidence Trumps SpeculationEvery. Single. Time.

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 12

Time Value of Information

A little information today is worth more than that same information tomorrow.

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 13

Eliminate Speculation Buildup

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 14

Beware Fragile

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 15

Beware Fragile

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 16

Beware Fragile

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 17

Beware Fragile

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 18

Beware Fragile

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 19

Beware Fragile

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 20

Different Kinds of Feedback

Local integration and unit testingAutomated tests in CIStory acceptanceExploratory testingEnvironment monitoring/metrics (canaries)Dog foodingSupport tickets

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 21

Visibility

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 22

Fast-and-Complete Feedback Recipe

Check + Explore + Release

— Automatically check that the emerging system behaves as expected with every new change.

— Explore both to discover other risks and to verify that the checks are sufficient.

— Release early and often.

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 23

Tighten Feedback Loops

— Work in small pieces

— Find and squash wait states

— Parallelize

— Remove duplicate tests

— Drive tests to the lowest level possible

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 24

Secret Sauce

Fast Feedback Creates Learning Organizations

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 25

Where I Need Help

CI is deploying a big distributed system.It can take 1-2 hours to run.How do you tighten feedback cyclesfor devs fixing a build?

Care and Feeding of Feedback Cycles, Elisabeth Hendrickson (@testobsessed) 26