AI makes tech debt more expensive

I recently watched a team speedrun this phenomenon in rather dramatic fashion. They released a ground-up rewrite of an existing service to much fanfare, talking about how much simpler it was than the old version. Only to spend the next year systematically restoring most of those pieces of complexity as whoever was on pager duty that week got to experience a high-pressure object lesson in why some design quirk of the original existed in the first place.

Fast forward to now and we're basically back to where we started. Only now they're working on code that was written in a different language, which I suppose is (to misappropriate a Royce quote) "worth something, but not much."

That said, this is also a great example of why I get so irritated with colleagues who believe it's possible for code to be "self-documenting" on anything larger than a micro-scale. That's what the original code tried to do, and it meant that its current maintainers were left without any frickin' clue why all those epicycles were in there. Sure, documentation can go stale, but even a slightly inaccurate accounting for the reason would have, at the very least, served as a clear reminder that a reason did indeed exist. Without that, there wasn't much to prevent them from falling into the perennially popular assumption that one's esteemed predecessors were idiots who had no clue what they were doing.

Hahaha, Joel Spolsky predicted exactly that IN THE YEAR 2000:

https://www.joelonsoftware.com/2000/04/06/things-you-should-...

> Only to spend the next year systematically restoring most of those pieces of complexity as whoever was on pager duty that week got to experience a high-pressure object lesson in why some design quirk of the original existed in the first place.

Just to emphasize the point: even if it's not obvious why there is a line of code, it should at least be obvious that the line of code does something. It's important to find out what that something is and remember it for a refactor. At the very least, the knowledge could help you figure out a bug a day or two before you decide to pore over every line in the diff.

In my refactoring I always refer to that as Chesterton's Fence. Never remove something until you know why it was put in in the first place. Plenty of times it's because you were trying to support Python 3.8 or something else obsolete, and a whole lot of the time it's because you thought that the next project was going to be X so you tried to make that easy but X never got done so you have code to nowhere. Then feel free to refactor it, but a lot of the time it's because of good reasons that are NOT obsolete or overtaken by events, and when refactoring you need to be able to tell the difference.

https://www.chesterton.org/taking-a-fence-down/ has the full cite on the names.

Times have changed. Code now does acquire bugs just by sitting there. Assholes you depend on are changing language definitions, compiler behavior, and libraries in a massive effort concentrated on breaking your code. :)

100% hear this and I know as a developer at a big company I have no say over the business side of things but there's probably something to be said for we should all push for clear logical business processes that make sense. Take something like a complicated offering of subscriptions, it's bad for the customer, it's bad for sales people, it's bad for customer support, honestly it's probably even bad for marketing. Keep things simple. But I suppose those complexities ultimately probably allow for greater revenue as it would allow for greater extraction of dollars per customer e.g. people who met this criteria are willing to pay more so we'll have this niche plan but like I outlined above at what cost? Are you even coming out ahead in the long run?

Incidentally the person who really convinced me to stop trying to future-proof made a point along those lines. Not in the same language, but he basically pointed out that, in practice, future-proofing is usually just an extremely efficient way to litter your code with Chesterton's Fences.

It acquires bugs, security flaws, and obsolescence from the operating system itself.

Golang really is the best when it comes to backwards compatibility. I'm able to import dependencies from 14 years ago and have them work with 0 changes

I got really 'lucky' in that the first major project I ever worked on was future-proofed to high heaven, and I became the one to maintain that thing for a few years as none of the expected needs for multiple layers of future-proofing abstraction came to pass. Oh but if we ever wanted to switch from Oracle to Sybase, it would have been 30% easier with our database connection factory!

I never let that happen again.

> Assholes you depend on are changing language definitions, compiler behavior, and libraries in a massive effort concentrated on breaking your code. :)

Big Open Source is plotting against the working class developer.

This can be a huge road block. Even if the developer who wrote the code is still around, there's no telling if they will even remember writing that line, or why they did so. But in most projects, that original developer is going to be long gone.

I leave myself notes when I do bug fixes for this exact reason.

> Sure, documentation can go stale, but even a slightly inaccurate accounting for the reason would have, at the very least, served as a clear reminder that a reason did indeed exist.

Which is borderline the reason for version control: Do a git/svn blame on that line, find what commit it was added, and see what the commit message was. Bonus points if it links to a case on a system you still use. Sure the commit message can be useless, but it's at least something you're forced to enter when committing code, rather than external documentation that can be missed and now be misleading. Version control can even show you that codebase at time that change was made so you can see it in context (which has saved me a few times, showing what something was added for so I could confirm a suspicion).

In general, when people say this sort of thing, if I dig into what exactly they're doing I discover they're importing half of npm/pypi/etc.

My code doesn't acquire bugs by sitting there in 2024 any more than it did in 2004. On most projects these days I'm using Django + Preact + HTM. Preact and HTM get loaded from static files by my root Django template. My PyPi dependencies are pinned to specific versions, and usually I have <10 (usually it's just Django and Django REST framework, sometimes it's even just Django).

> ...if we ever wanted to switch from Oracle to Sybase...

Yeah like Oracle would ever let that happen

Or phrased positively, Big Open Source keeping the working class developer employed

IME that kind of thing is more likely to make it 300% harder.

This idea of easy, worry-free database replatforming strikes me as kind of a shibboleth for identifying people who’ve never done it before. In reality they all have subtle differences in semantics and query optimization behavior that mean that every touch point needs close attention to make sure you understand how the behavior in that part of the system changes (assume it will change) and if that change is acceptable. Thinking abstraction layers can eliminate the need for close attention to a DBMS port is the software engineering equivalent of thinking adaptive cruise control means you can play Slay the Spire while driving to the office.

It was even more ludicrous in this case because a ton of the app logic was inside stored procedures.