Software etc.

This is a 30 minute talk I gave at the very first OpenAI Codex Meetup in Amsterdam on March 5th 2026. I introduced the concept of Dark Code . It was a lot of fun and the audience seemed to like it. My CMO gave me a 7-8 out of 10.  This is not an exact representation of the talk, I improvised, went off-script and forgot things. Also the organizers told me to say the f-word less (4 is bad, 1 would be OK), so in this transcript I've redacted it. At least if you say the f-word, you're quite sure it's not AI-slop ;) Hi, I'm Jouke and today I'm going to talk to you about Mapping out Dark Code. This is the very first Codex meetup here in Amsterdam, this is the very first presentation of the evening and it's also a first time we're showing Comper to a real-world audience. Lots of firsts. We're happy to be here! [the sentences appeared one by one, I do that all the time to make sure people follow my train of thought, and don't try to read everything at once] ...

Here's some insights about what the hiring process can look like from within a company. The title is a play on Adele's "Hello (from the other side)". Quick context: I’ve interviewed for about three jobs in my life and interviewed somewhere between 300 and 500 candidates for teams I led. So yes, my view is from the interviewer’s chair. I’m in software, which has its own hype cycles, but most of this applies broadly. What you’ll get here: A short glossary so we’re speaking the same language Three real hiring scenarios I’ve run What each one means for you A practical checklist to be the candidate they remember How companies talk about hiring (so you can decode it) This is how we talk about the hiring process, you'll might hear these terms but not all of them might mean something to you. Hiring Manager : Owns the budget and the final decision. Might not run the process day-to-day. Internal Recruiter : Works at the company, screens and coordinates. Often your main cont...

This is a short story about one of the stupidest things I ever did in my professional life, namely, dropping a physical server from the top of the rack in a data center. Spring is my favorite season, summer is actually better, but in spring it's clear that winter is over and summer is coming up. In early 2014 I was driving from the Mendix office in Rotterdam to our co-location data center (DC for short) in Amsterdam. I felt fantastic, and for a couple of reasons: I was driving my new car, I was paid to do an important job with a $10k 1U server in the boot, and as the cherry on top, it was finally  spring  and the weather was great! There have not many times in my life I felt this wonderful. Little did I know that I was now at the top of a rollercoaster, and on the way back I would feel very different. All of the physical servers at Mendix had Pokemon names. The one in my car was called Flareon. It had broken down a couple of weeks before and had gotten fixed by Hans, our ...

Over the years I've noticed a pattern when I'm developing software. When faced with a huge backlog of things to pick up, I tend to go with the tasks that give me the most energy. I've been calling this Energy Driven Development in my head. My team leads / PMs must have hated this back in the day, because I was often only giving a halfhearted attempt at the official sprint items, but I believe that it's often the right approach. When I wake up, and in the shower I'm already thinking about a problem and how to solve it, I should probably be working on that. What personally gives me energy is if there are "deep problems" that require an elegant solution, so if you let me focus on those things, you get a well-organized codebase out of it, making all future development a lot easier. I believe that if you have good engineers with a product mindset, they will have a well-developed intuition for what to work on. So if you're managing a backlog and are stuck in...

As I've written before , I've seen teams work in incredible burst of productivity. We achieved 10x productivity for a week or so at a time. I've always been fascinated by it. Wouldn't it be great if we can get closer to these peaks in our day-to-day? Having now seen dozens of teams in various situations, I think the ingredients for having the perfect storm of productivity are: Team wants to work for someone who cares about what they do. There is focus and clear priority for the work to be done. The team has the right resources at hand. You probably can't achieve 10x performance consistently, but most mission-driven startups get very close. If you have the feeling that something is wrong with your team's output, you can use the following flow-chart to find problems. Here's a PDF version .

Edit: since creating this post I've also created a video about this project on YouTube. See it below or jump straight into all the details below. Here's a very beautiful antique rotary phone. It's a Dutch PTT phone model called simply "1950" . But, what's this at the back? A USB-C port? A peek inside shows us some weird things! How did that LiPO battery get there? Ok let's quit the jokey intro, this was all me. I've had this phone for about 15 years and over the last couple of weeks I've converted into a fully functioning Bluetooth headset using an ESP32 microcontroller. In this post: - 1 - Features - 2 - Lessons Learned - 3 - Pictures and story!  of how it got made (scroll down!) but first... Does it work? This morning was the first Google meet I've used it in: A participant reported on the sound quality "I didn't know how much I missed the different sound quality! Beautiful. We could hear you very well, not distorted. I wish I record...