Comment by Reubend | Hacker News Reader

Comment by Reubend | Hacker News Reader

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> In my experience you can't rebuild such a thing "in 3 months". People who believe that are those that don't realize the complexity and the extraordinary amount of specifics, special cases, that are baked into the system, and any attempt to just rebuild from scratch in a few months hits that wall and ends up taking years.

Rebuilding a legacy system doesn't require you to support every single edge case that the older system did. It's okay to start off with some minor limitations and gradually add functionality to account for those edge cases.

Furthermore, you've got a huge advantage when remaking something: you can see all the edge cases from the start, and make an ideal design for that, rather than bolting on things as you go (which is done in the case of many of these legacy systems, where functionality was added over time with dirty code in lieu of refactoring).

> Rebuilding a legacy system doesn't require you to support every single edge case that the older system did.

Depends on context.

This isn't some social media fun site where you can live with some rough edges; in this context "edge case" may be someone with an health condition who is still entitled to a drivers license; or it could be someone who normally could get one but due to a health condition really shouldn't be allowed one!

This generally isn’t true in the case of government systems. For the most part they are performing tasks that are required by law, and it is not acceptable to stop some of them, even temporarily. If you’re lucky you can run the old and new systems side-by-side while the 100% feature migration occurs, but that isn’t always feasible.

Ya it's funny looking at all these 'business' programmers that if the application doesn't work can just loose the customer/money to another competitor. In regulated stuff you have to serve everyone. Much worse if your systems don't work there are potential consequences where people die and or there are riots in the street.

It's the opposite. Most government systems have paper-based alternatives, which they will happily tell you to use instead if their system breaks. This exact article's title should've given you a clue here. Imagine if Netflix turned off at night. That would be totally unacceptable for a business, because you're their boss, but it's fine for government.

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