Two best books in 2019

According to The National Library of Poland research, only 10% of Poles read at least 7 books per year. I know that we are not reading a lot, and it was no surprise for me. Conversely, this fact motivated me to investigate to do some health-check about my reading.

The challenge

At the beginning of 2019, I thought that I read approximately about 10 books a year, but I wasn’t sure. My regular peace is one book a month, but I didn’t measure it in any way. I’ve decided to change it.

Goodreads reading challenge was a game-changer for me. This technique meets the SMART goal requirement. It was specific, measurable and since I know that I read about 10 books a year, I could set a target that was also achievable. I’ve decided to commit to reading 15 books in the year 2019. In fact, I’ve managed to read 18 books.

From all of those 18 read books, I’ve selected two books that have the biggest impact on my career as a Technical Leader.

Best technical book

Designing Data‑Intensive Applications by Martin Kleppmann is a must-read for every Software Engineer.

If you think that you are not building (or will never build) a distributed system, look at Single-Threaded CPU Performance, for the last ten years. The CPU performance is not increasing so rapidly that it used to. That’s why we should learn how to build complex and distributed systems, using only commodity class machines.

Before I start discussing this book, we need to distinguish between two terms: competence and knowledge.
Competence is about ability, a certain area of skills that allows you to perform well. Knowledge is just only knowing things. In most cases, you can Google for facts you are looking for. Take a look at the following answer at Quora.

Why should I hire a software engineer if I can just copy and paste code from Stack Overflow?

  • Access to StackOverflow is Knowledge.
  • Knowing which code to copy from StackOverflow is Competence.

This book helps you gain Competence.

Let’s discuss the book itself. To align the level of the reader’s understanding of a more advanced topic, this book introduces fundamental databases or data related algorithms. You may be surprised how many Software Engineers do not know these things.

The most precious thing that you get from this book is a big picture view of how many databases and data processing frameworks work under the hood. Also, you will learn by example how to create distributed systems.

What is more, the author is not focusing only on a single technology or database. He constantly contrasting and comparing different solutions, both used today and that we were using some time ago. If you would want to only read databases documentation to gain this knowledge, you would have to spend far more time reading and analyzing it, that reading that book.

Best leadership book

What Got You Here Won’t Get You There by Marshall Goldsmith is a good lecture if you work a lot with other people, and obligatory lecture if you want to be a leader or manager.

What you need to know about the author is that he was a coach for many CEOs in multiple companies. That is an impressive achievement and I thought that this book may be valuable. Furthermore, my friend recommended it to me, so it was a must-read for me. What is unusual about this book is that the author focuses on one and only one aspect of leadership: Changing Your behavior.

Dr. Marshall, in the first part of his book, explained 20 common behavioral mistakes, that not only many people do, but most importantly many managers or directors commit. I constantly asked myself: “What I would do If I were in that situation”. Realizing that I’m not perfect, was an important discovery for me, which forced me to change.

The second part of this book, helps you discover your weaknesses and support you to change your behavior. It presents many techniques, most of which may be implemented right away.

On the other hand, this book is sometimes boring. It spends too much talking about the same issue or repeating itself. It could be more condensed.


Currently, I preparing my reading list for 2020. It will be only 12 books, but I want to select the best books that I can read. That is why I would welcome any suggestions from you.

If you are a Software Engineer, I would like to know your reading habits. Do you read more or less? What do you read? Can you recommend something? Leave a comment :)

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Agile IT Organization Design

General impressions

Agile promises to deliver solutions through collaborative effort, cross functional team design, modern programming methods and probably many more things. Because of that, it is hard to distinguish between part and parcel of Agile, and optional techniques that were developed over time. Agile IT Organization Design by Sriram Narayan is a bird’s eye view on Agile topics and tries to organize them.

Agile IT Organization Design

As the author mentions multiple things that are somehow related to Agile, starting with project estimations, through project finance and software development practices, ending with team room layout, the reader should be ready to jump over the wide variety of topics. Putting so many subjects in one book causes that specific aspects are discussed from time to time without any case-studies or detailed guidance how to kick start those ideas. It is valuable if you want to get a general idea, but mediocre if you want to get in-depth knowledge. There is nothing to worry about, because there are a lot of references to other publications or books, which may help you to explore more.

The good thing is that at the end of each chapter there is a summary, which after short skimming, helped me to create my own book reading order.

Author very often, explain reasons for doing things in a certain fashion. This approach helped me to reflect what and how I did in the past, and hopefully, it will help me make better decisions in the future.


This book is written for people from all walks of life. You can read it if you are a leader, a product owner, a software engineer or a stakeholder. It would be favourable if every person read that book, but it is not possible. If you work in a modern organization and you have the general understanding of bolts and nuts of Agile processes, you will probably not lose much by skipping that book. It is a good book for someone who would like to take a break from technical books and read something without code listings inside. Also, I would recommend this book to reach out for a particular chapter which are in the area of your interest.

Key takeaways

I have highlighted over 50 sentences in this book. Some of them to remember, other to think about or to discuss them with colleagues. I have selected 9 that stuck in my mind:

  1. End-to-end cycle time is more important than team development velocity.
  2. Doing sprints doesn’t make it iterative development.
  3. An engineering team without a clear leader may have trouble settling down on a solution design.
  4. The product is never mature; it is always maturing until it is finally obsolete.
  5. Move from a project centric model of execution to a product-centric model.
  6. Labeling people with job titles like an engineer, a manager, a QA, may have side effects.
  7. Spoken language influences the way we think.
  8. People say tl;dr to anything longer than a tweet.

Three levels of TDD


I’ve been using TDD technique for a few years. Most of the time with satisfactory a result. But it wasn’t an easy journey; it was a trip full of ups and downs. During this period my thinking about TDD has changed dramatically, or maybe I have changed my perception of testing and software development during this time? Indeed, yes I have.

Lasse Koskela in his book called “Test Driven: TDD and Acceptance TDD for Java Developers.” wrote that “TDD is a technique that evolves together with the practitioner.” In this blog post, I would like to describe my own evolution in this matter.

Red Green Refactor Circle

Level 1 - Fundamentals

You begin your journey with TDD. When you are new into something, you want to follow the rules strictly. One is TDD circle, which is “RED, GREEN, REFACTOR”. You have also heard about three laws of TDD defined by Uncle Bob:

  • You are not allowed to write any production code unless it is to make a failing unit test pass.
  • You are not allowed to write any more of a unit test than is sufficient to fail, and compilation failures are failures.
  • You are not allowed to write any more production code than is sufficient to pass the one failing unit test.

You are very confused about TDD because all examples that you can find relate to some mathematical/algorithmic problems. But in your daily job, you are obligated to write features, talk to DB and the other systems. You probably are struggling with complex dependencies, maybe you have to use mocks.

But finally, after some practice you start to see the benefits, which are:

  • You’ve noticed short feedback loop. Immediately, when you complete your implementation, you can launch the test to verify the correctness of your code.
  • Test code coverage gets higher. No matter how you measure it, it will be higher.
  • Regression is not a problem. Because when you break previous functionality during refactoring, you will instantly know that.

Level 2 - Requirements

Task lists

Task lists work perfectly for me. When I implement a business requirement, each small step or each corner case is represented by one task in my task list.

Then for each task I write one test, often I use parametrized tests to extend tests quickly. Finally, after a few TDD circles, my task is finally completed, and I can move on.

But sometimes during my work new system requirements appear. Often because the domain is so complicated that it’s hard to predict all the functionality up front. There is a big temptation to do it now, during the work on the current task, but it is dangerous. By doing it, you can lose your focus on your current goal.

I’ve practiced the habit which consists of adding this new requirement as a new task to my task list and complete it after the current one. Then you gain some time to think about this need, to decide if it is an essential functionality to do.


At some day, you will discover Behaviour Driven Development. For example, look at this specification:

Scenario: Customer has a broker policy so DOB is requested
Given I have a "Broker" policy
When I submit my policy number
Then I should be asked for my date of birth

It is a very well written test scenario. Moreover, it is an executable scenario. This text can be executed with the tool called Cucumber. You don’t have to use it. You can use standard test framework and write your test using fluent test libraries or you can build your fluent API for tests if needed.

Start writing tests that will not only check your code but also be valuable documentation for your system.

Level 3 - Understanding

Show me your tests and I will tell you everything about your code.

TDD sometimes can also mean “Test Driven Design”. When you start thinking about it, your main reason for writing the tests is to refactor and re-engineer your codebase freely. For me, it is the highest value which you can get from TDD. How to achieve it? Try not to “cement” your code. Try to test interfaces or facades but not bolts and nuts of the implementation.

How to check if your tests are correct? Remove production code and try to rebuild it in a different way basing only on tests.


In this article, I presented fundamental rules of TDD. The topic of requirements were also discussed. In the end, I told you about Test Driven Design which for me is a valuable part of this technique. I hope that your understanding of TDD will improve and you will start writing better tests and better systems.

I gave a speech about TDD. Slides available at

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Fish shell - Load environment variables from file

In many places, you can find environment files, with the following structure:


When you try to evaluate, this file using source command, you get an error with the fish shell.

$ source web.env                                                   
Unsupported use of '='. In fish, please use 'set FOO1 BAR1'.

This is very annoying, so I’ve decided to write a function that can read this file and load those variables. Here is how you can use it:

$ posix-source web.env
$ echo $FOO1

The source code of this function. Enjoy:

$ cat .config/fish/functions/                      
function posix-source
for i in (cat $argv)
set arr (echo $i |tr = \n)
set -gx $arr[1] $arr[2]

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Lessons learned from Decision Maker

In the past few weeks, I’ve read Getting Things Done, Technical Leadership, Elon Musk Biography and The Decision Maker.

Each of these books was good. But “The Decision Maker” is a game changer and I can’t stop thinking about this book. It was worth reading - for sure. I’ve decided to write a short book review and note the most important facts that I’ve learned from this book.


This book is a story about a company and its new owners who have left the corporation and decided to build a great place to work. It is full of dialogues, issues, and situations.

By observing those scenes, the author presents ideas and values that matter when you have to lead the team or the company.

Is this book only for managers or bosses? Certainly not. If you work with other people or deal with non-trivial tasks, this book is for you. For me, it is an appropriate supplement for any “Agile” book.

Blueprint presented in this book is a good starting point for setting up company culture.

The story did not take place in reality. Each scene looks genuine, but as a whole, it seems artificial. Like a romance from 90’s, when you know they will live happily ever after.

Lessons Learned

Spoiler Alert!

In the following section, some elements of the book are about to be revealed.


To begin with, you have to change your thinking about other people.


  • are unique,
  • are creative,
  • are able to learn,
  • have different strong points,
  • have different needs,
  • like a challenge,
  • are capable of changing the environment,
  • are capable of making contribution,
  • can be trusted.

Among some people, you can see those values. Among others, you have them hidden, and you have to unlock them.

But there is always somebody who disagrees with it and this is important to remember it. Do you see any similarities with Theory X and Y employees?

Decision Maker

Secondly, you have to choose the Decision Maker. It is a person who makes a decision. How to find them? It is simple.

The Decision Maker is a person, who is closest to the action. Bosses or leaders are not often deeply familiar with the situation. Usually, team members are often closer to the problem.

The Decision Maker has to be capable of listening and understanding other people. Making a decision is a process, in which you have to talk and listen to the others.

The Decision Maker should be aware of what is going on. Awareness of facts and consequences is crucial. If the person does not have basic data for making decisions - like company current finance status - you are responsible for unlocking that data.

Wisdom and knowledge are desirable qualities of that person.

It is a leader’s job to choose the Decision Maker. The leader should also observe and monitor the Decision Maker to see if he makes good decisions. If not, something should be done by the leader.

Results of making decision

It turns out that your employees’ decisions are often as good as or even better than yours can ever be.

People who are allowed to make the decision feel the ownership, because of that they will do everything to make the best possible decision.

Advisory process

The purpose of the advisory process is to look for a wider perspective.
The Decision Maker should ask at least a few people what they think about the decision.
He or she should ask:

  • team members,
  • other people with experience,
  • subordinates and superiors,
  • anyone who can help.

But the Decision Maker should take the final call.

Silver bullet

The decision maker process is not a silver bullet. It is only one tool or technique. The bigger picture is not straightforwardly visible in the book.

Between the lines, you can see many behaviours and dialogues which look familiar in “Teal Organizations”. If your organization is not ready, the decision maker process is definitely not the road to follow.

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