> if you're one of the few people that understands some legacy technology that is important and hard to replace, then you have job security I've never seen th

> if you're one of the few people that understands some legacy technology that is important and hard to replace, then you have job security I've never seen this play out in practice. The PHB doing the firing is 3 levels up and has no idea what the legacy technology is or that the employee is hard to replace. They'll be more than happy to fire them even when it screws themselves over. Everyone left has to learn to work with or around this technology.