A new solution in
a month?
I'll do it in two weeks.

It's a prototype, right?

We are going to throw it all away, right?

#greenfield #ftw

Two weeks later

• You know the overall structure
   

• The APIs are simple
   

• Development is fun

  • Low cognitive load

  • Fast Changes

Boss: Hey, Your software is great!
Let's add some features ...

Brilliant, the customers love it.

They just need one more thing.

"Hmm, i thought there was already a method for this ... but nevermind..."

6 months later ...

• You know the overall structure

• The APIs are simple

• Development is fun

  • Low cognitive load

  • Fast Changes

Uncle Bob

“reading versus writing is
well over 10 to 1.
We are constantly reading old code as part of the effort to write new code. ...[Therefore,] making it easy to read makes it easier to write.”

Reading to Writing
10 to 1 !
Fast comprehension >
Fast keyboard

How we understand software

(with a small brain)

Top-Down Comprehension:
 

• how seniors do it

• Hypotheses based on  existing knowledge

• Search for places to prove or falsify them

Bottom-Up Comprehension:
 

• Search for things you recognize

• Combine known units to understand
  larger sections

Default for most Developers:
 

Start with top-down analysis
 

Apply Bottom-up  when You
recognize something
while validating

How many items can your brain handle at the same time?

Your Working Memory:

max. 7 (+2) items

Developers chunk and slice code to understand it.

Known Patterns &
Ignored Lines

Spaghetti Monolith

Predictable Implementations
a.k.a.

Design Patterns

ca 1995

Monoliths:
As long your brain stays small
large software stays slow.

Source: Steve McConnell, Software Sizing

Layered Architecture:

I still need to understand every layer for debugging :/

Catalog


 

Domain Driven Design

Inventory


 

Orders


 

Payment


 

ca 2005

DevOps: Move Complexity to places where you can automate it.

Faster Understanding
with more Observability

Faster Feedback =
Less things to remember

Catalog
Service


Elastic
Search

MicroServices

Inventory
Service


PostgreSQL
 

Orders
Service


MySQL
 

Payment
Service


-
 

ca 2013

MicroServices

• can be deployed independently -> fast feedback
• provide one business capability -> smaller domain
• have no dependency on central governance or external data management
• use on automated infrastructure / integration / deployment

Microservices: Software that fits in your Head

Dan North

Couldn't just somebody else care about the complicated stuff?

Serverless

Automate All The Things!

ca 2015

• should be "service-full"
  • Function as a Service / Lambda /λ
  • Serverless databases / Aurora etc
  • SQS, SNS, ELB, Route53,
• function as a deploy unit
• Pay-as-you-go
• Scaling is a solved problem
• Event-driven
• You won't get fired for choosing AWS

Observability included

Text

Text

5 lines of λ
 

50 lines of
configuration

But ...

Ok, and what should i do about it?

Rule #1:
Optimize your brain, don't optimize technology.

The amount of time understanding sourcecode has not decreased notably in 30 years.

Rule #2
Mastery in One Language

Needed for:

• Top-Down Comprehension

• Design Patterns

• Craftership

Mastery in One Language

5 years,  full-time

• "10.000 hours for mastery"

• backed by scientific research
  for program comprehension

Coding-Dojos &  Pair Programming:

• smart algorithms
• common idioms
• design patterns
• solution strategies

Rule #3
One more language...

Understand your work/
co-workers:

• JavaScript/TypeScript for
  Browser-Dev
   
• Kotlin/Swift/Dart for
  mobile Development
   
• Python/R for data analytics
   
• Go for fast services ...

Rule #4: a helpful environment 1

IDE Support

Use a helpful environment 2

Automation

Use a helpful environment 3

Observability

The Secret: How to become a
10-times programmer

1. Organize coding dojos at in your team
2. Do a lot of pair programming
3. Practice clean code
4. Train until 5 of you are 3 times more effective
5. Done, that's even better than one 10 times programmer!

What comes next

Genesis & Prophet (2016)

Automatic error detection & Patch Generation
16 of 39 Patches are correct

DeepCode.ai

Trained on existing fixes from Github

Analyses your code and recommends known patches

askbayou.com

• Military Project
• Create new Programs based on sketches

import java.io.*;
import java.util.*;
public class TestIO {
    void read(File file) {
        {
            /// call:readLine type:FileReader type:BufferedReader
        }
    }
}

import java.io.*;
import java.util.*;
import java.io.FileReader;
import java.io.File;
import java.io.IOException;
import java.io.FileNotFoundException;
import java.io.BufferedReader;

public class TestIO {
  void read(File file) {
    {
      FileReader fr1;
      BufferedReader br1;
      String s1;
      try {
        fr1 = new FileReader(file);
        br1 = new BufferedReader(fr1);
        while ((s1 = br1.readLine()) != null) {}
        br1.close();
      } catch (FileNotFoundException _e) {
      } catch (IOException _e) {
      }
      return;
    }
  }
}

So, i still have to work in future?

The amount of time understanding sourcecode has not decreased notably in 30 years.

We didn't win, but we didn't loose, either.