Hi, I'm Dennis Krul

As director of operations I'm responsible for the teams and the roadmap behind our servers, storage, virtualization, networking and datacenters.

I've been a Linux/UNIX systems engineer, a PHP web developer, a founder, product owner, team lead and architect, so I know the work from the inside, and I still like to understand how things run before deciding how they should.

I engineer software, but I wouldn't call myself a software engineer: I build things to make computers do what I want.

My job is no longer hands-on, so I tinker at home and try to keep up with new tech.

My main project is EMS, which manages the energy in our house and replaced Home Assistant; more on the EMS page, its electricity prices under Energy. My desktops and servers run Debian.

Our house is fully electric: 30 solar panels on a 7.4 kW inverter, an air-source heat pump, induction cooking, the home battery and an IONIQ 5. The gas connection is gone, which saves its fixed charges too. I did it for the climate, for the cost, to depend less on gas, and because it's a fun system to build and tune.

I haven't found a downside: it's cheaper than before, the heat pump keeps the house at an even temperature, and road trips across Europe never had me worried about range.

I use AI a lot, to build my own software and run my infrastructure: this site, EMS and the price API behind the Energy page were made that way. I don't call it vibe coding but co-development: I'm the architect and analyst, with the experience of what makes software good, and AI agents are my coders, testers and advisors.

It does worry me that I'm coming to depend on a few frontier models, a new big-tech dependency in the making. Open-weight models are nearly good enough, but running them at home is still impractical; I hope that changes in the coming years.

I'd rather fix my own things, own my data and keep it private than depend on someone else, and I look for the free alternative first, free as in freedom. Working in hosting, I'd also like Europe to depend less on the handful of American companies that run much of the internet.

So I self-host: OpenCloud for files, Immich for photos, Forgejo for code and CI/CD, on a Proxmox server at home and VPSes and backups at EU-owned hosting companies. I left Facebook and X and kept LinkedIn for work; this site is my place on the web instead, with nobody's algorithm in between.

I'm not dogmatic: my mail is with Fastmail, and I use a smartphone, streaming services, AI tools and, for work, Microsoft and the big clouds. I just like to know what I depend on, and to keep a way out.