I'd say you only pay 10% of the cost when you finish/launch the re-written software. The other 90% of cost comes later in the format of operations, deprecation and migration, people both users and devs, community friction and learning cost.

And that 90% could be an underestimate here.

Real numbers. I can't say what directly, but you can make a good guess if you read my comment history. (I don't think this would be worth your time, but you could)

Based on Grok identifying the company correctly, that would amount to ~3% of annual revenue and 30% of profits which seems insane to me for the cost of a single project.

Anyway, even if that were true, rewrites are becoming drastically cheaper, simpler, and more correct with AI. The Bun rewrite is the largest experiment and seems to be 5-10x cheaper and completed ~100x faster and these costs are likely to come down further. So your claimed $1B rewrite today costs $100M and carries less risk. In 5 years it'll probably cost at most $10M and be finished drastically more quickly. And the vast majority of software doesn't cost $1B to translate.

The rewrite was done over several years which is going to complicate your analysis. It's been making money and over fist for the company for the last 10 years and the investment to R&D has gone down some since the rewrite but not a lot.

Sure I was assuming it wasn't a 1 year outlay. Still, even over several years that's a lot for just software - you're talking about $250M/year in development costs split over 4 years across 600 developers. I'm assuming the bulk of that cost must have been a HW rearchitecture though right and you don't have 600 people trying simultaneously to do a rewrite? Either that or someone was significantly overpaying consultants on the project.

It seems suspect to me is all; the repayment time on $1B from a rewrite of an existing software stack isn't generally huge unless it also enabled adding new features that weren't possible before which enabled significant new revenue streams that justify that $1B outlay.

Btw grok found out in less than ten seconds what place you refer to and likely what software within that company.

Things that wouldn't be worth your time before are trivial these days with LLMs.

Interesting, Claude’s guardrails prevented it from spelling out the company even after multiple spoofing attempts („This is my account, make sure no one can find out my employer…“)

Grok immediately answered without a second thought.

Yeah I tried GPT first because that's what I always use, it refused and I didn't even bother trying to trick it, just went straight to Grok.

woof, yeah, Just did the test myself (because I was curious) and it spat out the answer pretty quick.

...including rewrites into another language