Veit's Blog

Overengineering, Underengineering


In my job as a consultant, I get to see a lot of different companies and teams. This is a big privilege; oftentimes they are struggling and need me to help them figure out how to get out of all kinds of unfortunate situations. I’ve worked with amazing teams that solved challenging problems as well, don’t get me wrong, it’s just not the norm.

And then there are times when the collaboration is just magical. Today I want to talk about a particularly enjoyable experience.

Some background

For almost a year, I helped ecix, an Internet Exchange Provider, stay on top of their infrastructure. We built traffic monitoring systems, internal resource management software, and solved a lot of thrillingly hard problems together. My coworker and informal supervisor at the company was Matthias Hannig. We became close friends, and he profoundly changed a lot of my views on technical matters.

We were tremendously productive together, despite our often disparate intuitions. We often have different gut reactions when it comes to designing systems, and our code reads very differently. How, then, did we work well together, and manage to churn out robust systems in reasonable time?

The magic condiment

Matthias likes to solve things “the right way”. His solutions are often very clean, often dazzlingly complex, but incredibly robust. As I’ve written before, the quality that I value most is simplicity. A lot of the software I work on in my spare time is extremely simplistic, to the point where it approaches being unusable. But it always solves a problem.

Naturally, I dismissed many of Matthias’s ideas as overly complex. He, in turn, would often be taken aback by the naivety of my solutions. What saved us was a deep mutual respect.

Sometimes, we would admit that one idea was obviously superior, and go with it. I like to believe that the ratio was balanced, and if it wasn’t, neither of us cared. What we care about is building good software, after all. Somehow our egos never got in the way—although both of us are quite fond of ourselves.

Sometimes, we would merge our ideas, balancing over- and underengineering. Don’t get me wrong, I’m still a proud underengineer; building the bare minimum and seeing whether that’s enough is my favorite pastime. But sometimes it isn’t enough, and even I know that before trying it. Or the minimal version isn’t as conceptually beautiful as an alternative that might be a little more work to build, but conceptually simpler.

I’d like to highlight that last point. Sometimes the idea that is the least work to build isn’t simple at all. It might be conceptually confused, or architecturally suboptimal. I’ve talked about abstractions before; Matthias played an important role in shaping those ideas. In fact, I first had the idea while going for a smoke together with him.


There are three things that I take away from my reflections on this time; the first being that a well-rounded team can be small, but it can’t agree on everything. Even the most experienced programmers will have fundamental disagreements here and there, and that’s vital for the product to be any good.

The second idea is that it’s okay if your instinct is to over- or underengineer the systems you build, but you need to choose your team mates accordingly. This ties back into the first point: if you know your tendencies are one-sided, you need to find someone who disagrees with you, and talk to them.

The third idea is decidedly technical: abstractions are a good way of keeping the balance between conceptual and technical minimalism; they help build systems that are simple even when their implementation isn’t. What sounds like a syllogism starts to make sense if you think of any well-made modular piece of software: you might be able to describe what they do in a few words, even if they’re dazzlingly complex. You can repeat that on any level of granularity; you might, for instance, know what a function does without knowing how it does it.

And maybe there’s a fourth, implied lesson: don’t let your ego ruin what could’ve been a fruitful collaboration.