Learning again, Nov 2020-Mar 2021

5 min readMar 21, 2021

While preparing for my new life and business in a new place, which is in Amsterdam, the Netherlands, since November 2020, I used a lot of time to learn new things.

Since 2015, when I started working on iOS app development, I’ve focused on iOS/Swift things and haven’t spent much time learning outside of the iOS/Swift world. This was a strategic choice and I learned a lot by exploring Swift.
However, I felt the time has come to learn outside of iOS/Swift, to have broader and deeper knowledge about software development.

This is a simple list of things I’ve learned in these 5 months. I’m writing this primarily as a footprint of my career. However, it would be my pleasure if this gives some hints to developers who are ambitious to learn more.

Things I’ve learned

Programming languages

  • Haskell

(Still reading)

  • Rust
  • Scala
  • Languages themselves

(It seems functional programming principles are a part of the current trend of programming language features.)

  • Category Theory: The theory behind Haskell
  • LLVM: Compiler infrastructure that supports lots of languages including Swift, Rust, Haskell, etc

One of my favorite lectures at my university was a workshop to make a C compiler by ourselves. Learning LLVM reminded me of the workshop.

  • Javascript Engine: “How does a web browser work?”
  • Elm: a functional language for declarative UI

Elm community looks nice as well!

Developers’ habit

As I like pair-programming and scrum workflow, I wanted to learn the origin of them.

Catch up on new swift usages

  • SwiftUI Tutorials
  • SwiftUI for iOS 14 from Design+Code
  • Getting started with Swift on AWS Lambda

While doing this tutorial, I used Docker for the first time.


  • Docker

Docker seems so interesting to me…

  • Updated my Server (Ubuntu)

Attend conferences

  • MobileOptimized 2020
  • GitHub Universe Virtual 2020

Great conference. I learned a lot about OSS culture.

  • VS Code Day 2021
  • Community.o (by LLVM Foundation)

This was a relatively small, but dense conference. I got more interested in compiler technologies and their community.

  • Mozilla Festival 2021

Mozilla Festival was wonderful for people like me interested in interdisciplinary things, such as society, ethics, digital city, culture, art, and technology.

Career and software community

  • Open Source Software culture
  • Burnout (which seems quite common among software devs)

Very encouraging post.

  • Internet culture

A book about prochronism and the internet culture. It’s about how to save or express processes of digital content creation.

Freelance business

  • Dutch business rules
  • Financial stuff (bank, tax, accountant, …)
  • Make resume and portfolio
  • Update equipment (monitor, webcam, …)
My new environment with a new monitor

Life improvement

  • English study (business vocabulary, business writing, academic vocabulary, …)
  • Explore Amsterdam and Dutch culture
  • Learn Dutch


  • I really felt that a programmer constantly needs time to catch up with new things. Especially it’s important to know what’s happening outside of one’s primary tech stack. “20% rule ” like in Google seems to make sense in this point. As I became a freelancer, I hope I can gain control over the time I use.
  • My interest in programming languages has become stronger. I want to learn more about Haskell because it’s so interesting to learn. I want to catch up with Rust because it seems promising. Learning more about LLVM feels interesting as well to know how languages work.
  • I wanna keep my eyes on social things: open-source culture, areas between society and technology, and technology-art. Even though I’m not sure what I can do, it might be good for me to invest a little bit more time in this area considering my interests and background, which is interdisciplinary information studies which I studied at university. At least it was very encouraging for me to know people with similar interests and struggles when I attended Mozilla Festival.

Thank you very much for reading! If you want to follow my activities, please follow my Twitter @yoshikuni_kato as I occasionally tweet my interests.




Software Engineer. Based in Europe since 2019, originally from Japan.