oarsinsync 30 minutes ago

Huge respect to the author for the details that have gone into this. I'd spent a week hammering at a Claude max 20x plan to try and build schengen 90/180 rolling window + tax residency in a couple of countries tracker... and that was hard work. I can only imagine how much effort has gone into this, to get all the details right.

It's unclear whether the author wrote all of this themselves, or if they outsourced a bunch of it to Claude. My experience with Claude was that it was terrible at writing code to do the math, even when I explained what the calculation needed to be, what the input was, and what the expected result was. It ultimately took starting a whole new project just to do the rolling window calculation, and then have that fed back in.

My biggest question for the author, if they happen to see this, is: how much manual testing validation did you do of the outputs the app produces? IE: Did you do the inputs + transformations = output calculations yourself as well, counting days on calendars, etc, to validate that the app is actually accurate? (That was the only way I developed any faith in solution I made for myself, which is way less impressive than your app). Regardless of whether you wrote the code yourself or not, a thorough test harness feels vitally important for an app like this.

bambax 16 minutes ago

There's some similarity between nationality and copyright: arcane, obscure, complex and mean rules that only benefit incumbents and punish everyone else.

I hope we will eventually get rid of both.

  • teiferer 9 minutes ago

    At the rate things are going, even EU and Schengen, areas in which their citizens are blissfully unaware how nice they have it compared to outsiders, are going to come to an end. Far-right nationalists are on the rise over Europe.

evadne 24 minutes ago

This is an impressive article, & is incidentally why every sane set of rules has administrative discretion in its enforcement

exidy 18 minutes ago

It's a cool app, and makes me wish that Australian tax residency rules were actually computable.

clacker-o-matic 6 hours ago

that was fascinating; I didn’t realize border requirements were that complicated.

  • swiftcoder 20 minutes ago

    Now try international taxation rules (particularly if you come from one of the handful of countries with world-wide taxation, like the USA!)

  • rmunn 40 minutes ago

    It grows exponentially the more countries are involved. I am a citizen of country A but live and work in country B, and I have to satisfy country B's visa requirements, which involves quite a bit of paperwork. I also have to pay taxes to country A, which involves more paperwork. It gets complicated.

    But I'm only dealing with the requirements of two countries. The author mentioned five or six countries; I'm glad I'm only dealing with two.

raverbashing 5 minutes ago

The problem with those rules is that they "all make sense" somewhat (and where details might have been influenced by local idiosyncrasies) locally but if you mix and match them then it gets weird

But the trick here is: if you're relying on the details for your benefit then make 100% sure it's provable (though tbh legal proof is less - and different - than what your HN commenter might understand). Or just make it easy on yourself and don't rely on them