1. 1
#CD22
Managing Complexity
Keep your software under control!
27.05.2022 1

2. 2
#CD22
David Felkel
Founder of helpful bits
Software Architect
Programming since 1997
Salesforce since 2016
https://helpfulbits.com
27.05.2022

3. 3
#CD22
Part 1- About Complexity
27.05.2022

4. 4
#CD22
Complexity kills
• Budget
• Quality
• Engineers‘ Motivation
• Extensibility
• Customer Support
27.05.2022

5. 5
#CD22
Complex software is like a jungle
27.05.2022

6. 6
#CD22
Simple software is a garden
27.05.2022

7. 7
#CD22
What is complexity in software?
A problem of state
27.05.2022
n The number of Latin squares of order n
1 1
2 2
3 12
4 576
5 161,280
6 812,851,200
7 61,479,419,904,000
8 108,776,032,459,082,956,800
9 5,524,751,496,156,892,842,531,225,600
10 9,982,437,658,213,039,871,725,064,756,920,320,000
11 776,966,836,171,770,144,107,444,346,734,230,682,311,065,600,000
1 2 3
2 3 1
3 1 2

8. 8
#CD22
Where is the relation to software?
• Combinatorial explosions occur a lot in software
• Branches in Program Flow
• Possibles states of data increase with every new field
• Now suppose you‘ve got 4 picklists with 10 values each:
• 10.000 possible states of data
• Have you got 10.000 unit tests for that?
No? Shame on you, sloppy programmer!
27.05.2022

9. 9
#CD22
Or a global variable for that matter …
Congrats, you can now multiply all already possible states of your
whole program!
You will win the award for the most stateful program!
And you better pray the next maintenance developer does not
know where you live! I suggest you leave the country!
27.05.2022

10. 10
#CD22
What is complexity in software?
A problem of cognitive load
27.05.2022

11. 11
#CD22
Where is the relation to software?
• The same things are named differently
• The same thing is being done differently
• Different things have the same name
• There‘s simply too much of the same thing in different flavors
• Communication Problems
27.05.2022

12. 12
#CD22
What is complexity in software?
A problem of features
• People buy feature-rich software
• People want powerful software to fuel their processes
27.05.2022

13. 13
#CD22
What is complexity in software?
A problem of premature optimization
“The real problem is that programmers have spent far too
much time worrying about efficiency in the wrong places
and at the wrong times; premature optimization is the
root of all evil (or at least most of it) in
programming”
(Donald Knuth, 1974)
Yet, we are often forced to do so in Salesforce. It worsens
the problem.
27.05.2022

14. 14
#CD22
The solution: KISS – Keep IT simple and stupid
• Complex code is bad code
• Simple code is good code
• Simple code is not easy to write, it‘s easier to write complex
code
• Simple code with better modularization has less state than
complex code and makes you think less.
27.05.2022

15. 15
#CD22
We‘ve known this since the 70s
• Structured Programming promoted by Djikstra
27.05.2022
How do we convince people that
in programming, simplicity and clarity –
in short: what mathematicians
call „elegance“ – are not a dispensable luxury,
but a crucial matter that decides between
success and failure?

16. 16
#CD22
What is simple and maintainable code?
27.05.2022

17. 17
#CD22
And how do we achieve less complexity?
• Boundaries!
• Divide & Conquer! Everywhere!
• Modularization!
• Encapsulation!
• True Object Orientation!
• Readable and clean code!
• Be close to your domain, no unecessary abstractions!
• Stupid code!
27.05.2022

18. 18
#CD22
27.05.2022

19. 19
#CD22
Part 2 – Practical solutions to complexity
problems
27.05.2022

20. 20
#CD22
Fundamentals
• Establish Coding Conventions
• They teach your eyes and your mental parser
• Code will make you think less
• You can prevent errors with proper conventions
27.05.2022

21. 21
#CD22
Fundamentals
• Establish a ubiqitous language
• Enable your business people and your programmers to understand
each other!
• Any business term should have a precise meaning and only that
meaning
• These terms should be found in the code
27.05.2022

22. 22
#CD22
Fundamentals
• Clean Code
• Vast topic – I recommend Uncle Bob‘s book ‚Clean Code‘
• Don‘t make the maintenance programmer think
• Don‘t duplicate code
• Don‘t have methods more than a few lines and don‘t have more than 3
Arguments
• Etc. etc.
27.05.2022
Any fool can write code that a computer can understand.
Good programmers write code that humans can understand.”—Martin Fowler

23. 23
#CD22
Fundamentals – clean code
27.05.2022

24. 24
#CD22
Fundamentals – clean code
27.05.2022

25. 25
#CD22
Fundamentals – clean code
27.05.2022
There are only two hard things in Computer Science: cache invalidation and naming things.
Phil Karlton

26. 26
#CD22
Fundamentals
• S ingle Responsibility Principle
• O pen Closed Principle
• L iskov Substitution Principle
• I nterface Segregation Principle
• D ependency Inversion Principle
https://en.wikipedia.org/wiki/SOLID
27.05.2022

27. 27
#CD22
Fundamentals
27.05.2022

28. 28
#CD22
Fundamentals
• Use proper tools for the job
• 1st Rule is: DON‘T USE EVERYTHING IN YOUR SALESFORCE TOOLKIT
• 2nd Rule is: DON‘T USE EVERYTHING IN YOUR SALESFORCE TOOLKIT
• 3rd Rule is: Understand the tools you use
• Flows and Processes are hard to debug, yet accessible for non
programmers
• Good combinations:
• Pure Apex and LWC for complex domains
• LWC with flows for lots of step by step processes and wizards
• No Apex at all and just flows for simple domains
27.05.2022

29. 29
#CD22
Fundamentals
• Key Success factor:
• Requirements Engineering: Know what you are up to, because the
client most likely won‘t pay for refactorings.
• Team Setup: Know your teams skills.
• Have the guts to say „no“ to the client
• If in doubt, use Apex and LWC, avoid Workflows and Processes.
A Flow here and there probably doesn‘t hurt.
• Workflows and processes are harder to debug and, together with rollup
summaries, cause triggers to fire a 2nd time, counting against your
limits.
27.05.2022

30. 30
#CD22
Part 3 – Architecture primer
27.05.2022

31. 31
#CD22
Architecture Fundamentals
• The Layer Architecture (aka n-Tier architecture)
• Clear separation between Persistence, Business Logic and UI
27.05.2022
Only call down, never call up!

32. 32
#CD22
Architecture Fundamentals
• There‘s fflib:
https://github.com/apex-enterprise-patterns/fflib-apex-common
https://trailhead.salesforce.com/en/content/learn/modules/apex_patterns_d
sl
• I consider it too heavy weight but you might like it.
• Architecture is more a pattern than a library, you can roll your
own.
27.05.2022

33. 33
#CD22
Architecture Fundamentals – Business Logic
• API Layer
• Well defined API for a Business Domain
• Encapsulates the actions your business really does
• Properly published via Facade Pattern
• Done properly, you won‘t have to bulkify (or at least loop) much
anymore
• Can avoid „Trigger cascades“ if done right
27.05.2022

34. 34
#CD22
Architecture Fundamentals – Data Access
• The lazy Repository (aka Kazlovich Repository)
• Is initialized with all IDs necessary
• Only fetches records or relations when actually accessed
• Uses mainly one big query to fetch as much data as possible in a single
database call
• Great in avoiding complexity and limits!
27.05.2022

35. 35
#CD22
Architecture Fundamentals – Presentation
• LWC or Visual Force
• Avoid Aura for its complexity and lack of readability is its meat and
bones
• Don‘t write business logic in your code, rather call Backend methods
• The UI should only care about presentation logic and not much about
the business process, apart from visualizing it!
• No Javascript business logic algorithms!
• Patterns used in other technologies: MVC, MVVM, MVP
27.05.2022

36. 36
#CD22
Architecture Fundamentals – DDD
• Define module boundaries in your requirements
27.05.2022
Done right, any domain will fit into a salesforce
Package and not depend on others

37. 37
#CD22
Why is this so important?
• Proper architecture means proper divide and conquer
• Proper divide and conquer = less complexity
• Proper decoupling = less complexity and even more
flexibility
• Properly architected, well defined interfaces and
decoupled modules emerge naturally
27.05.2022

38. 38
#CD22
Summary
• How does this solve Salesforce problems technically?
• You can avoid limits
• You can even avoid the need for bulkification
• Your code is more clean and concise
• Your code is easier to maintain, more flexible
• Your code is more easily extensible
• Your code is easier to deploy
27.05.2022

39. 39
#CD22
Summary
• How does this solve Salesforce problems organizationally?
• Quick changes
• Less bugs
• Multiproject Management
• Clear separation of organizational responsibilities
• But: It‘s not easy getting there. Proper conventions and
guidelines have to be created. Any building block must confirm
to your standards.
27.05.2022

40. 40
#CD22
27.05.2022

41. 41
#CD22
27.05.2022
Thank you!
#CD22