It takes 12min total to craft.Have you tried checking that before answering?It becomes more and more clear that misinfo is spread across the community.
Well, it used to be the case and plenty of people who already had a railjack likely didn’t keep tabs on that once the whole RJ rework and DE making it easier to build. So it’s just outdated rather than a lie.
Only children and idiots think like that. Everyone else knows that if you speak your "truth" to a boss/manager/supervisor, you won't have a job. Just because you have the anonymity of the internet doesn't give you free reign to be a dick. It's not the "truth" you're just an asshole.
It used to take a while, but they massively sped it up shortly after New War released. The Rising Tide quest is all about building a railjack. To start it, you have to build a thing that takes 10 minutes. Then during the quest you go on a series of defense-style missions to collect blueprints of each of the six parts. Each takes only 1 minute to craft in the foundry.
So, if you have all the necessary resources, it'll only take 16 minutes of active build time. The mission time is the longest part now; I don't remember how long the missions take, but they aren't that long.