This document summarizes a presentation about developing software for a connected coffee machine. It discusses the challenges of developing 50,000 lines of code for a product that needs to be agile, connected across devices, secure, and work offline. The presentation covers prototyping approaches used from paper prototypes to a functional prototype that could brew coffee. It also discusses lessons learned around prioritizing hardware constraints early, allowing for complex offline user flows, automating testing, and the importance of co-locating software and hardware teams.

1. c o d e . t a l k s 2 0 1 5 , H a m b u r g , S e p 3 0 t h 2 0 1 5
50000 LINES OF CODE TO BREW
A COFFEE

2. WHY THIS TALK?
2

3. STRUCTURE AND TOPICS
3
PROTOTYPES
TESTING
ENVIRONMENTS
SECURITY
agile approach
challenges
adopted approach
introduction
lessons
learned

4. PROJECT OVERVIEW
4
PRODUCT
SYSTEM
CONNECTED
PRODUCT
SMART
PRODUCT
PRODUCT

5. KEY CHALLENGES
5
STAY AGILE IN A GLOBAL PROJECT

6. KEY CHALLENGES
6
GETTING THINGS CONNECTED

7. KEY CHALLENGES: GET CONNECTED
7

8. KEY CHALLENGES
8
EVERYTHING IS OFFLINE

9. KEY CHALLENGES
9
USER FLOWS
ACROSS DEVICES
1
2
3
4
5
6
7

10. KEY CHALLENGES
10
THERE IS NO MACHINE

11. KEY CHALLENGES: GET THE UX RIGHT!
11Photo by Wikipedia/Terabass CC BY-SA 4.0

12. KEY CHALLENGES
12
HTTPS?! JSON?!
That’s just fancy candy
for the internet kiddies…
01100111001101010101 !!!

13. PROTOTYPES
13

14. PROTOTYPES
14
DUMMIES
low fi
hi fi
clickable
WALKING
SKELETON
Hello World!
ALPHA
core
functions
BETA
real
users
RELEASE
live!

15. PROTOTYPES
15
DUMMIES
USER TESTING / IDEATION
3D PRINTED
SPEAKERS TO MAKE COFFEE SOUNDS

16. 16
7

17. PROTOTYPES
17
FAKE
SERVICE
NEEDED TO IMPLEMENT APP / BACKEND
SOFTWARE THAT CAN RUN ON ANY DEV MACHINE

18. 18

19. PROTOTYPES
19
FAKE
MACHINE
WIFI SETUP DEVELOPMENT
BEAGLEBONE + NODE.JS

20. 20

21. PROTOTYPES
21
THE
BOX
SOME REAL HARDWARE
REAL USER CONTROLS
DOESN’T BREW COFFEE

22. Double-click to edit

23. PROTOTYPES
23
FUNCTIONAL
PROTOTYPE
and nally …

24. … YEAH! SOME COFFEE :)
24Photo by Wikipedia/Takeaway CC BY-SA 4.0

25. PROTOTYPES
25
DUMMIES
WALKING
SKELETON
ALPHA BETA RELEASE
DUMMIES
FAKE
SERVICE
FAKE
MACHINE
THE
BOX
FUNCTIONAL
PROTOTYPE

26. PROTOTYPES
26
DUMMIES
WALKING
SKELETON
ALPHA BETA RELEASE
DUMMIES
FAKE
SERVICE
FAKE
MACHINE
THE
BOX
FUNCTIONAL
PROTOTYPE
minutes
hours
weeks
months

27. PROTOTYPES
27
DUMMIES
WALKING
SKELETON
ALPHA BETA RELEASE
DUMMIES
FAKE
SERVICE
FAKE
MACHINE
THE
BOX
FUNCTIONAL
PROTOTYPE

28. TESTING
28

29. 29
“YOU CAN'T BE
AGILE WHEN YOU'RE
KNEE-DEEP IN MUD”
Martin Fowler

30. AGILE
30
working
software
fast
feedback
respond to
change
simplest
solution
automation
small, continuous
improvements
LIGHTWEIGHT
FAST
FLEXIBLE

31. TESTING
31
unit
integration
functional

32. TESTING
32

33. CONTINIOUS INTEGRATION FTW!
33

34. TESTING
34
CONTRACT
TESTS
FAKE / GUIDED
USER
INTERACTION
PARTIAL
USER
JOURNEYS

35. ENVIRONMENTS
35

36. ENVIRONMENTS
36
dev machine
cloud cloud
cloud

37. ENVIRONMENTS
37
dev machine

38. ENVIRONMENTS
38
phone
cloud
local device
wi
local device
wi
local device
wi

39. ENVIRONMENTS
39
cloud desk
automatic manual
minutes hours

40. SECURITY
40

41. SECURITY
41
What is the
agile approach
to security?
cross functional teams
automated testing
automated provisioning
threat modelling

42. SECURITY
42
scenario I: you break your own machine
oh…

43. SECURITY
43
scenario II: you break somebody else’s machine
oh…
haha!

44. SECURITY
44
scenario III: you break ALL machines
it doesn’t stop!
haha!
what happened?!
I want coee!
oh…

45. LESSONS
LEARNED
45

46. LESSONS LEARNED
46
resources matter, hardware is hard to change
software has to be build around it
5
offline + complex user flows
analyse more than you used to
4
don’t reinvent the wheel
when getting things connected
3
automate more than
you first think is possible
2
co-locate with the hardware people1

47. THANK YOU!
LET’S MEET AT OUR
STAND
47