This document outlines Trello's process of developing product principles to guide design decisions. It began with informal "Trello-y" guidelines that caused confusion. Formal principles were introduced to be universal, easy to understand, describe how not what, and complement quantitative data. The principles are visual, direct, flexible, collaborative, fun, succinct, and personal. They are demonstrated through improved onboarding that is more visual, direct, and performs better. The principles provide a framework to critique designs and make decisions while still allowing flexibility.

1. COURTNEY DRAKE | DESIGN MANAGER | @COURTYDRAKE
Key Principles That Guide
Trello Design

2. TRELLO:
THE BEGINNING

4. Photographer; Source (example.flickr.com)

11. HORIZONTAL PRODUCT
Redfin
Marketo
JIRA
Salesforce
Real Estate Marketing Tech Sales Trello

12. Real World
Analogies
Constraint Flexibility Shared
Perspective
Initial Core Tenets

13. “Trello-y”

14. INTRODUCING
PRODUCT PRINCIPLES

15. Team Size
Explaining unofficial principles gets inefficient
and new hires get frustrated
Opinions Veiled as Objectivity
When “Trello-y” is code for “I don’t like it”
Feedback Isn’t Actionable
So it’s not “Trello-y”…how do I improve it?
When is it
time for
principles?

17. Product as a Whole
Developing Principles
Just Enough
Description
How (Not What)

18. Trello Principles
Universal
Trello lets
anyone bring
perspective to
their life
Easy
A new user can
be up and
running in a few
minutes
Personal
Get perspective
on work and
home you do in
one place
Visual
Use distinctive
visual elements
instead of
relying on text
Familiar
Our core design
patterns come
from the real
world

19. Trello Principles
Succinct
If you need to
add new
vocabulary, it’s
too complicated
Direct
Users can
directly
manipulate
objects
Flexible
Don’t prescribe
how to use
Trello, users
shape it to fit
them
Collaborative
Trello is
optimized to
help groups of
people work
together better
Fun
Trello has a
personality. It's
friendly, witty,
light, and
helpful.

20. Design Critique
PRINCIPLES IN PRACTICE:

21. “I like that it’s
direct, but
could it be
more visual?”
“It’s not
Trello-y
enough.”
BEFORE AFTER

22. Decision Making
PRINCIPLES IN PRACTICE:

25. Play off of Quant Data
PRINCIPLES IN PRACTICE:

26. Principles supersede data, but
ideally they complement each
other
PRINCIPLES + QUANT DATA

27. PRINCIPLES
IN THE WILD

28. WELCOME BOARD ONBOARDING
Visual
No explicit instructions, aside
from card and list content
Direct
Use the product while learning
how it works
Not Performant
Not activating users at the rates
we wanted

34. MADLIBS ONBOARDING
Visual
Show board being built,
explanation is minimal
Direct
User populates mini board,
which becomes their first board
Personal
User creates a board specific to
what they’re trying to get done
Performant
Activates users at higher rates
than other onboarding tests
Easy
Users can set up their first board
in minutes

35. TRELLO
PRODUCT PRINCIPLES
• Core tenets that resonated with users
• Growing pains may mean it’s time for principles
• Principles should live alongside quant data

36. Thank You
courtney@trello.com
@courtydrake