Chapter 5 - Bend Or Break

John: Welcome to Iteration: A weekly podcast about programming, development, and design through the lens of amazing books, chapter-by-chapter.

Quick update: Sketch Color Spaces

Today we'll be going through Chapter 5, "Bend or Break" - where we talk about writing flexible code. This is especially important for software engineers in a profession where things are constantly changing. (insert joke about JavaScript frameworks). We will largely focus on different ways we can decouple our code!

Life doesn't stand still. Neither can the code that we write. In order to keep up with today's near-frantic pace of change, we need to make every effort to write code that's as loose—as flexible—as possible.

Part 1

Tip 36: Minimize Coupling Between Modules

Organize code into modules and limit interaction between them. If one module gets compromised and has to be replaced, the other modules should be able to carry on.

Avoid coupling by writing shy code and applying the law of Demeter

What is shy?

• JP: shy doesn't reveal itself to others and doesn't interact with too many people. write shy code. you don't want this: selection.getRecorder().getLocation().getTimeZone()
• John: What does this loo lie practically? Short methods? How do I avoid "coupling?"

Tip 37: Configure, Don't Integrate

Implement technology choices for an application as configuration options, not through integration or engineering

• JP: algo choices, database products, middleware -> these should be configuration options. doing so makes our code more flexible. this is described as "soft" - aka easy to change
• John: Example: Platform fee, or simple basic shared defaults.

Tip 38: Put Abstractions in Code, Details in Metadata

Program for the general case, and put the specifics outside the compiled code base

• JP: think declaratively - not imperatively. specify what, not how. Think about how you write your business logic and business critical things. Think about where you would call these functions or methods. it should be declarative
• John: leave the details as soft—as easy to change—as we can. - "Weekend" automated emails example - valid_send_days
• John: Challenge from book: For your current project, consider how much of the application might be moved out of the program itself to metadata.

Tip 39: Analyze Workflow to Improve Concurrency

Exploit the concurrency in your user's workflow

• JP: temporal coupling - aka coupling in time - aka thinking linear-ly. Decouple your time / order dependencies. ask yourself: what can happen at the same time?. This is a good thought experiment

This example was really good so I'm copying it from the book:

making a pina colada

1 open blender
2 open pina colada mix
3 put mix in blender
4 measure 1/2 cup white rum
5 pour in rum
6 add 2 cups of ice
7 close blender
8 liquefy for 2 mins
9 open blender
10 get glasses
11 get pink umbrellas
12 serve pina coladas

Think about how imperative this is. First do this... then do this...

BUT, think about what you can do concurrently: 1, 2, 4, 10, 11. These can happen all at the same time and up front. Next, 3, 5, and 6 can happen concurrently afterwards. These would be big optimizations

Picks

• JP: Pocket Developer Die
• John: AppSignal - Dropped Rollbar + Scout for this one service.