A senior dev could get into a new stack reliably within ~3 months. And it doesnt 'take' effort to train them - they just do it themselves. And the cost of loss

A senior dev could get into a new stack reliably within ~3 months. And it doesnt 'take' effort to train them - they just do it themselves. And the cost of loss of people who know the existing product, business model, existing codebase is WAY too great than a few months' pay. That's something that comes only by having people on board for long duration and having them accumulate experience of the existing product and business model. Most people from MBA background has little understanding of this. They tend to see engineers as replaceable - you just bring in someone who knows a new stack while passing to that new stack and youre done (the best case scenario). It doesnt work like that. When you lose experienced engineers who know the product and the codebase in a fast moving startup, you lose people who you need to ask stuff when you need to do something new. Especially when the codebase lacks sufficient documentation (common in startups). Then the newcomers have to learn the codebase all over again - a gigantic hit to productivity. This is why people from non-engineering background should not make engineering hiring/firing decisions.