Daniel’s programming rants

Production Readiness Checklist

Modern applications run typically in the cloud. As good residents, distributed applications must fulfill many requirements in order to enable reliable operations and maintenance. This article summarizes the most important points in order to go live and to keep applications healthy over their lifetime. Twelve-factor app All modern cloud applications should comply with the 12-factor app principles: Codebase is tracked in a version control system, the same code will be deployed in different environments Dependencies are shipped with the deployable artifact Backing Services can be detached and re-attached without code changes (e....

November 13, 2023 · 4 min · Daniel Gerlach

DDD and SOLID: A refactoring story

TL;DR Command-Query Separation Extract Use Cases (Clean/Hexagonal Architecture) Domain Events (with Eventhandlers and Composite Pattern) Cross-Cutting Concerns (with Decorator Pattern) Many backend applications end up as a big ball of mud where small changes ripple through the whole codebase. The root causes are high coupling and low cohesion. The best remedies against those are Domain Driven Design (DDD) and the SOLID principles which are well-known, but often wrongly applied....

July 19, 2023 · 11 min · Daniel Gerlach

Top 10 Practices Of Effective Software Engineers

TL;DR Write code Read Code (Written) Communication Learn concepts – not technologies Learn Lisp Master your tools Control complexity (Simplicity) Read books (but don’t forget to practice) Understand the problem domain Learn to write good tests (or how to design well and write decoupled code) Introduction I am always pondering what practices, tactics, behaviours and approaches make up the most successful software engineers. After 15 years working in the industry, in small and big teams, with waterfall and agile processes, and after thousands of written lines of code, I present here an opinionated way of how to become an effective engineer....

April 11, 2023 · 16 min · Daniel Gerlach

Effective CLI (more productive than an IDE!)

TL;DR Modern Terminal with nice (Nerd) Fonts ZSH oh-my-zsh Modern Prompt with starship Modern CLI tools (fzf, ripgrep, bat, tmux, jq) Fast editor (Emacs, Neovim, Helix) Organize your dotfiles with GNU Stow The Unix shell/Command-Line Interface (CLI) is an ancient tool. Despite being around forever, the shell is highly customizable and with a good configuration, it is on par with modern graphical IDEs. Because it is configurable, you can make it truly your own, thereby surpassing out-of-the-box experience of IDEs....

January 16, 2023 · 11 min · Daniel Gerlach

Best Books For The Inquisitive Software Engineer

This article contains a list of my favorite books with a major impact on my Software Engineering career. The books are categorized in: Software Engineering Programming Brian Kernighan’s Books Modern Classics Learning Management and Leadership Unix Books From Stevens Software Engineering A Philosophy of Software Design by John Ousterhout Link to book A fabulous book to level up your software design skills as an experienced engineer. The book is full of great advice....

November 4, 2022 · 16 min · Daniel Gerlach

Software Engineering and Feedback Loops

Introduction Most of the breakthrough inventions in historic and modern Software Engineering are related to feedback loops. They are essential for productive software development, Developer Effectiveness and Developer Happiness. Remember the dawn of computing when computers were programmed with punch cards, programmers had to turn in their cards over night and the next day they got the result – often with a compile error 😞. Unlike back then, today’s computers compile whole codebases in seconds....

September 29, 2022 · 7 min · Daniel Gerlach

The Non-Productive Programmer (NPP)

We all know them: programmers with long term experience stuck on a low-level of our craft not corresponding to their quantity of experience. Great programmers are creative workers and problem-solvers and one of their most important traits is: never stop learning – but getting stuck in its own comfort zone and becoming reluctant to change is deeply wired into human nature (Humans are hard-wired to follow the path of least resistance)....

December 18, 2021 · 9 min · Daniel Gerlach

Reading List for the mindful Software Engineer

Abstractions are essential in order to build complex systems and keep complexity under control. Especially in software development we rely on many abstractions to make our life easier. Although good abstractions do not “leak”, it’s always helpful to understand the background and the details behind them. The following list (in chronological order) of classic computer science papers will give you insights of inventions of the last decades which are considered nowadays common sense....

September 10, 2021 · 11 min · Daniel Gerlach

Database Integration Tests with Docker Sidecar in Jenkins

More often than not, developers want to test the source code against a real database instead of Fakes or Test Doubles during a CI job in order to verify the code works as expected. Therefore a clean database is needed for every CI-job. One solution is to use a shared instance of the database in your existing test-environment which get cleaned before and after a job. But this suffers from being “shared” and you never can run multiple CI-jobs in parallel without jobs interfering with each other....

May 9, 2021 · 2 min · Daniel Gerlach

Emacs as RSS reader

Do you have a list of websites you visit regularly? Just to find out nothing new was added. This manual scraping is often a waste of time. Worse yet, scanning and filtering these websites for new interesting content is even more time consuming. Subscribing to an RSS feed can reduce your effort immensely. An RSS feed “pushes” the newest updates to subscribers and they will never miss updates. In order to make use of RSS feeds you need a “feed reader” or “feed aggregator”....

October 10, 2020 · 2 min · Daniel Gerlach