Corporate best practices for upstream open source contributions
This post is based on presentation given at the Validos annual members’ meeting on June 25th, 2025.
2025
Creating Debian packages from upstream Git
In this post, I demonstrate the optimal workflow for creating new Debian packages in 2025, preserving the upstream git history. The motivation for this is to lower the barrier for sharing improvements to and from upstream, and to improve software provenance and supply-chain security by making it easy to inspect every change at any level using standard git tooling. Key elements of this workflow include: Using a Git fork/clone of the upstream repository as the starting point for creating Debian packaging repositories. Consistent use of the same git-buildpackage commands, with all package-specific options in gbp.conf. DEP-14 tag and branch names for an optimal Git packaging repository structure. Pristine-tar and upstream signatures for supply-chain security. Use of Files-Excluded in the debian/copyright file to filter out unwanted files in Debian. Patch queues to easily rebase and cherry-pick changes across Debian and upstream branches. Efficient use of Salsa, Debian’s GitLab instance, for both automated feedback from CI systems and human feedback from peer reviews. To make the instructions so concrete that anyone can repeat all the steps themselves on a real package, I demonstrate the steps by packaging the command-line tool Entr. It is written in C, has very few dependencies, and its final Debian source package structure is simple, yet exemplifies all the important parts that go into a complete Debian package:
Going Full-Time as an Open Source Developer
After careful consideration, I’ve decided to embark on a new chapter in my professional journey. I’ve left my position at AWS to dedicate at least the next six months to developing open source software and strengthening digital ecosystems. My focus will be on contributing to Linux distributions (primarily Debian) and other critical infrastructure components that our modern society depends on, but which may not receive adequate attention or resources.
Debian Salsa CI in Google Summer of Code 2025
Are you a student aspiring to participate in the Google Summer of Code 2025? Would you like to improve the continuous integration pipeline used at salsa.debian.org, the Debian GitLab instance, to help improve the quality of tens of thousands of software packages in Debian?
Will decentralized social media soon go mainstream?
In today’s digital landscape, social media is more than just a communication tool — it is the primary medium for global discourse. Heads of state, corporate leaders and cultural influencers now broadcast their statements directly to the world, shaping public opinion in real time. However, the dominance of a few centralized platforms — X/Twitter, Facebook and YouTube — raises critical concerns about control, censorship and the monopolization of information. Those who control these networks effectively wield significant power over public discourse.
10 habits to help becoming a Debian Maintainer
Becoming a Debian maintainer is a journey that combines technical expertise, community collaboration, and continuous learning. In this post, I’ll share 10 key habits that will both help you navigate the complexities of Debian packaging without getting lost, and also enable you to contribute more effectively to one of the world’s largest open source projects.
Debian source packages in git explained
Most people with Linux experience have at some point installed .deb files on Debian or the more famous variant of it, Ubuntu. Programmers who have been involved with packaging and shipping software know that the code that generates those .deb packages is always in the debian/ subdirectory in a software project. However, anyone who has tried to do Debian packaging also knows that all the automation involved can be challenging to grasp, and building packages, modifying packaging files, and repeatedly rebuilding them can feel way more frustrating than iterating in regular software development. As Debian has been around for three decades already, there is a lot of online documentation available, but unfortunately, most of it is outdated, and reading about old tools might just add to the confusion. Thus, let me introduce an explainer of what the structure in 2025 should look like on a well-maintained Debian package source, and what benefits it brings. First, I’ll run through the basics to ensure all readers have them fresh in their mind, and further down, I get into the increasingly complex workings of how Debian source packaging works and why they have a certain git repository structure.
2024
Are AI language models capable of doing financial forecasting?
Considering LLMs are basically massively big statistical machines, a logical assumption would be that they should be well suited for predicting how the economy and the stock market develops. Let’s conduct a small test to see if that holds for the largest generic LLMs of today.
The Simple Art of Effective Decision-Making for Managers
A large part of a manager’s role is to make decisions and be responsible for their outcomes. While there is ample advice on how to be successful in many other managerial core areas, such as growing your people, the domain of high-quality decision-making seems less crowded. In this post, I summarize what I have found during my 20+ years as a manager to be a simple and effective way to approach decision-making.
Should developers always just write code and never design documents?
In software engineering, most ideas can be implemented without writing any design document at all. This is particularly prominent in open source communities. For example, the Linux kernel has 35 million lines of code that have been written and rewritten many times over alongside 30 years of mailing list discussions. Linux wasn’t created as a result of a grandiose design document by Linus Torvalds, but it evolved organically in small increments of actual running code.
Heartbleed and XZ Backdoor Learnings: Open Source Infrastructure Can Be Improved Efficiently With Moderate Funding
The XZ Utils backdoor, discovered last week, and the Heartbleed security vulnerability ten years ago, share the same ultimate root cause. Both of them, and in fact all critical infrastructure open source projects, should be fixed with the same solution: ensure baseline funding for proper open source maintenance.
Communication Is the Key to Efficiency in a Software Engineering Organization
For a software engineering organization to be efficient, it is key that everyone is an efficient communicator. Everybody needs to be calibrated in what to communicate, to whom and how to ensure information spreads properly in the organization. Having smart people with a lot of knowledge results in progress only if information flows well in the veins of the organization.
8 Writing Tips for Software Professionals
People usually associate advanced software engineering with gray-bearded experts with vast knowledge of how computers and things like compiler internals work. However, having technical knowledge is just the base requirement to work in the field. In my experience, the greatest minds in the field are not just experts in knowledge, but also extremely efficient communicators, particularly in writing.
Tab-tastic tips for streamlined web browser use
What is the single most common action you repeat over and over when using your computer? Let me guess – opening a new tab in the browser. Here are my tips for opening, switching and closing tabs everyone should know.
Advanced git commands every senior software developer needs to know
Git is by far the most popular software version control system today, and every software developer surely knows the basics of how to make a git commit. Given the popularity, it is surprising how many people don’t actually know the advanced commands. Mastering them might help you unlock a new level of productivity. Let’s dive in!
Learn to write better git commit messages by example
When people learn programming they – for completely obvious and natural reasons – initially focus on learning the syntax of programming languages and libraries. However, these are just tools. The essence of software engineering is about automating thought, applying algorithmic thinking and anticipation of the known and unknown. The code might be succinct, but the reasoning behind it can be extensive, and it needs to show in the communication around the code. The more senior a programmer is, the more their success depends on their communication skills.
When everyone else is wrong
The stock market is a powerful globally distributed forecasting system. Last Friday it was forecasting a rosy future as the MSCI World index got to a new all-time high. But it does not make sense.
2023
Make habits, not goals
First we make our habits, and then they make us ― John Dryden, poet and literary critic
How to conduct an effective code review
In software development, the code review process stands as a crucial checkpoint for ensuring code quality, fostering collaboration, and promoting knowledge sharing among team members. Despite the importance, many engineers lack a clear mental map of how effective reviews work. This is my attempt to help code reviews and reviewers improve.
My 5 tips for efficient meetings
While large organisations scale best by emphasizing asynchronous communications, in-person or video meetings also have their place. As a manager who is involved in a lot of planning and coordination work I’ve noticed that I’ve spent the majority of my working time in meetings in past years. These are my 5 tips to make meetings as efficient as possible.
Pulsar, the best code editor
The key to being productive as a programmer is to have a great code editor. I have been an avid user of Atom since 2014, and its successor Pulsar since now in 2023.
Unpacking Linux containers: understanding Docker and its alternatives
In popularizing Linux containers, Docker brought about a new era of systems design based on these lightweight platforms, rather than heavy virtual machines. However, now that Docker is slowly declining, it’s time to learn about the next generation of Linux container tools.
The optimal home office
The perfect home office setup achieves two things: it helps you stay focused for extended periods, allowing you to be in “the flow” and it prioritizes ergonomic design to ensure that long hours at the computer don’t compromise your health.
How to make a good git commit
As a software developer, your core skill is how to improve an existing code base to make the software better iteratively, patch by patch. To be a good software developer you need to: understand the concept of a code patch, know how do code improvements in well sized and properly documented patches, and skillfully use git version control software to manage patches.
Quick builds and rebuilds of MariaDB using Docker
The MariaDB server has over 2 million lines of code. Downloading, compiling (and re-compiling) and running the test suite can potentially consume a lot of time away from actually making the code changes and being productive. Knowing a few simple shortcuts can help avoid wasting time.
Grokking the MariaDB test runner (MTR)
The main test system in the MariaDB open source database project is the mariadb-test-run script (inherited from mysql-test-run). It is easy to run to and does not require you to compile any source code.
How to code 10x faster than an average programmer
What is the key to being an efficient programmer? Well, the answer is surprisingly simple. Having a setup where you can write and test your code over and over in an uninterrupted flow will dramatically increase your productivity.
2022
Resist the urge of the first solution
This is the biggest and most common mistake I see that prevents people from thinking clearly, and it is also the most difficult one to unlearn.
Ensuring software quality with GitLab CI – case MariaDB in Debian
Of all CI systems I’ve used during my software development career, both as developer and manager, GitLab CI has proven itself to be the overall best system out there.
Stop the senseless killing
In over 22 years of working with Linux systems, I have often seen people use excessive force to kill various computer programs, causing unnecessary suffering.
Truth, health and wealth
With so many options to choose from and with so many solutions offered by others, each screaming pick me!, people too often lose sight of the actual goal. In the most complex system of them all, life itself, I find it much easier to navigate when the priorities are clear. Money is not number one. It is just a means to an end. In my opinion, the best choice of priorities and in this order are: truth, health and wealth.
The optimal
Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away. ― Antoine de Saint-Exupéry, aviator and author
