Some good points. Laughed at TDD is a cult. I mean a lot of software orgs/cultures are cultish (Agile, Scrum, whatnot). At work I often feel I'm part of a cult.
I've interop'd with JS from Haskell and you can just go full dynamic property access. And gradually add phantom typed APIs around it.
console.log also still works fine
My take on static vs dynamic is that a sufficiently motivated programmer can make a mess out of anything they're given, and that types actually really don't help that much. Furthermore, "the types work out!" is also not actually an incredibly comforting fact to me. There are so many more places things can be wrong. And I also find that the types of errors static typing prevents tend to not be the most meaningful errors to prevent or the hardest to catch in subsequent testing, ESPECIALLY with gradual typing!
With python in particular, gradual typing with a checker gets you 99% of the benefits of static typing, with the HUGE added benefit of you just being able to tell the type checker to stfu when it's not adding value. ORMs and data parsing are so much easier in dynamic languages, for instance. And I find the most ergonomic ORMs and data parsers in static languages tend to be the ones that have gone to extraordinary lengths to make them feel like the stuff you just get much more cheaply in dynamic languages. I have recently been writing python with basedpyright and very intentional type hinting and it has been my favorite experience in a long time. More impactful to my productivity (real productivity - actually producing things that work and are real) than AI.
At the time, a lot of it felt "important" and "significant". And some of it probably was at the time, to the businesses I wrote it for. But whether I sweated blood and tears to craft the most elegant and efficient software I was capable of, or I phoned it in and just copy/pasted Stack Overflow answers together until I met some interpretations of a requirement to be able to leave the office on time - really made no difference.
I've been pondering lately, thinking about GenAI and vibe coding, with the very real risk of creating completely unmaintainable codebases - whether that matters, if the code is likely to be retired or rewritten in 3-4 years anyway? My current gig is on to the 4th rewrite of it's web/mobile app backend platform in 15 years, which started out as a Groovy on Grails app, which got rewritten in Java, then rewritten again in Java, and now it's being rewritten in Python. Each rewrite had fairly good reasons at the time, but a huge amount of code here gets thrown away every 4 years or so - which looking back makes me seriously question whether any of it was "of any significance". To be honest, the 2026 Python code really isn't doing anything notably different or more complex than the Perl and JavaScript code I was writing in 1996 - web work is CRUD apps all the way down.
I've been coding professionally for >30 years. I don't think any of my code has survived 5 years in production.
I don't think code quality affected that at all - I know the really, really, shitty code I wrote when learning OOP in the 90's survived for a looong time, while the amazing code I wrote for a startup 2018-2021 died with it.
A lot of code makes a difference but I guess there's a lot that doesn't?
Posted on a significant website built in a dynamic language.
I tend to disagree. Static typing can catch some bugs, but most serious errors are not type errors, and the common situation where the type system disallows just enough invalid states for developers to get complacent is the worst of both worlds.
The entire AI ball of wax is built on python (dynamically typed) - or at least a large part of it. It probably needs to move to rust to save on power and compute cost.
Design-by-Contract[0] is a formalization of this concept and well worth considering when working in code using mutable types. In addition to pre/post conditions, DbC also reifies class invariants (which transcend method definitions).
Python is also the choice of non-programmers for simple work. Nothing wrong with that. But I wouldn't want e.g. my car's ABS system to be programmed in Python (or my browser or my OS or many other examples).
This gets more terrifying if you've ever experienced spurious ABS activation. It's the third scariest thing that's happened to me in a vehicle.
Fourth was probably a makeshift bridge over a creek collapsing while crossing it as a passenger on an ATV. I was pretty young when that happened.
That said, the people who change companies aren't the ones that believe that management ever had the best ideas, or are able to push back on the cult thinking with clarity. Unfortunately, though, it's not necessarily evidence that wins arguments, it's charisma, which is how the cult is started in the first place.