DevOps Enterprise Summit 2019 slides

1. 1
Monoliths vs Microservices
Team Cognitive Load
Case Studies
Getting started

2. Team Topologies
2
Organizing business and
technology teams for fast flow
Matthew Skelton & Manuel Pais
IT Revolution Press
Order via stores worldwide: teamtopologies.com/book

3. 3
Book signing ✍
TODAY
@ 19:15

4. Monoliths vs
Microservices
4

5. 5

6. “Start with monolith and
extract microservices.”
- Tammer Saleh
6
https://www.infoq.com/presentations/cloud-anti-patterns

7. “Don’t start with a
monolith when your goal is
a microservices
architecture”
- Stefan Tilkov
7
http://martinfowler.com/articles/dont-start-monolith.html

8. “If you can't build a
monolith, what makes you
think microservices are
the answer?”
- Simon Brown
8
http://www.codingthearchitecture.com/2014/07/06/distributed_big_balls_of_mud.html

9. 9
WTF?!?!
* where to focus?

10. “Software that
fits in your head”
- Daniel Terhorst-North
10
https://speakerdeck.com/tastapod/microservices-software-that-fits-in-your-head?slide=62

11. 11
“Software that
fits in our heads”

12. 4 key metrics: ‘Accelerate’
12
lead time
deployment frequency
mean time to restore (MTTR)
change fail percentage

13. Software that is ‘too big for
our heads’ works against
organizational agility
13

14. Team Cognitive Load
14

15. COGNITIVE LOAD:
The total amount of
mental effort being used
in the working memory
- John Sweller
15

16. Intrinsic
Extraneous
Germane
16
“How are
classes
defined in
Java?”

17. Intrinsic
Extraneous
Germane
17
“How do I
deploy this
app,
again?”

18. Intrinsic
Extraneous
Germane
18
“How do
bank
transfers
work?”

19. Intrinsic (skills)
Extraneous (mechanism)
Germane (domain focus)
19

20. (Intrinsic)
] Extraneous [
Germane
20

21. More: ‘Hacking Your Head’
21
Jo Pearce
(@jdpearce)
https://www.slideshare.net/JoPearce5/hacking-your-head-managing-information-overload-extended

22. Limit the size of software
services/products to the
cognitive load that the
team can handle.
22

23. 23
“Software that
fits in our heads”

24. A ‘team-first’
approach to software
boundaries
24

25. Team size ≲ 9 *
* possibly 15
25

26. 26
Each service must be fully
owned by a team with
sufficient cognitive capacity
to build and operate it.

27. Whole-team
techniques (mobbing)
27

28. Well-chosen domain
boundaries (DDD)
28

29. Developer Experience
#DevEx
29

30. Operator Experience
#operability
30

31. Thinnest Viable Platform
(TVP)
31

32. 4 fundamental topologies
32
Stream-aligned team
Enabling team
Complicated Subsystem team
Platform team

33. 4 fundamental topologies
33
Flow of change

34. 3 core interaction modes
34
Flow of change
X-as-a-Service
Facilitating
Collaboration

35. “...trend analysis, simulations, rapid
prototyping, scenario planning,
gaming, environmental scanning
… give clues to the context and
competitive environment.”
- Dr. Naomi Stanford,
“Guide to Organisation Design” (The Economist)
35

36. Case Studies
36

37. CaseStudy
37

38. CaseStudy
38
2016
(early)

39. CaseStudy
39
2016
(late)
CMS

40. CaseStudy
Framework
40
2017
(early)
CMS
Products

41. CaseStudy
Framework
41
Products
2017
(late)
CMS

42. Team became too large
⇔
System became monolithic
Blocked flow of work across streams
42

43. Listen to ‘triggers for evolution’
❏ Software grows too large
❏ Over specialization (Brent)
❏ Increased coordination needs
43

44. CaseStudy
44

45. CaseStudy
45
CD Enablement
Infrastructure
Automation
Test
Automation
Build & CI
Support

46. CaseStudy
46
CD Enablement Infrastructure
Automation
Test
Automation
Build & CI
Support

47. It’s not always about software size...
More broadly, align size and number
of domains of responsibility
with team cognitive capacity.
47

48. Aim for teams with high cohesion internally
(think autonomy, mastery & purpose)
Aim for low bandwidth comms
between smaller teams
48

49. Listen to ‘triggers for evolution’
❏ Awkward interactions
❏ People not invested, burn out
❏ Frequent context switching
49

50. Getting started with
team cognitive load
50

51. How well can the team as a unit “grok”
the systems they own and develop?
Explicit cognitive load
51

52. Push some things into a Platform?
Explicit cognitive load
52

53. Are skills or capabilities missing?
Explicit cognitive load
53

54. What would change if we adopted the
3 team interaction patterns?
Collaboration, X-as-a-Service, Facilitating
Team Interactions
54

55. Collaboration, X-as-a-Service, Facilitating
How would teams react & behave?
Team Interactions
55

56. How is your Platform defined?
Thinnest Viable Platform
56

57. What is the thinnest platform that
could work?
Thinnest Viable Platform
57

58. What’s needed to run and support it?
Thinnest Viable Platform
58

59. Team Topologies
59
Organizing business and
technology teams for fast flow
Matthew Skelton & Manuel Pais
IT Revolution Press
Order via stores worldwide: teamtopologies.com/book

60. Training
60
Day 1
Fundamentals
Day 2
Deep Dive
Day 3
Applying in Context
teamtopologies.com/training

61. Looking for case studies
61
Global manufacturing company
Large government agency
Global financial services

62. Remaining problems
62
Measuring cognitive load at scale
Assessing team communication at scale
How to nudge managers and heads of X
to become Team Topologies enablers

63. TeamTopologies.com
@TeamTopologies
Sign up for news and tips:
TeamTopologies.com

64. Thank you!
teamtopologies.com
64
Matthew Skelton, Conflux
@matthewpskelton
Manuel Pais, Independent
@manupaisable
Copyright © Conflux Digital Ltd 2018-2019. All rights reserved.
Registered in England and Wales, number 10890964
Icons made by Freepick from www.flaticon.com - used under license