Startups don't use Java because Java is for large-scale stable long- lived enterprises, not for prototyping simple small web apps that might be thrown away in a couple of years.
You often hear this, but what does it actually mean? Why is Java for one but not the other.
Here is my understanding.
Java was designed to limit the damage that any developer could accidentally do, rather than maximize the potential for productivity. Which is an appropriate tradeoff for a large team.
It is hard to get good statistics on this, but the figures that I've seen in books like Software Estimation suggest that the productivity difference is around a factor of two.
This matters because it turns out that teams of more than 8 people have to be carefully structured based on the requirements of communication overhead. (A point usually attributed to The Mythical Man-Month.) This reduces individual productivity. Smaller teams can ignore this problem. The result is that measured productivity for teams of size 5-8 is about the same as a team of 20. But the throughput of large teams grows almost linearly after that. An army does accomplish more, but far less per person.
Limiting damage matters more for large teams. Which are more likely to be affordable for large enterprises. However being in such an environment guarantees bureaucracy, politics, and everything negative that goes with that.
By contrast startups can't afford to have such large teams. Therefore they are better off maximizing individual productivity so that they can get the most out of a small team. And using a scripting language is one way to do that.
Today, I go back and forth between three languages at work - .Net, JavaScript, and Python. For simple prototype web apps or more realistically REST microservic APIs to feed front end frameworks, I really don’t see either being slower to develop.
For larger applications with multiple developers working in the same code base, the compile time checking of static languages is a god send. I would at least move over to TypeScript instead of plain JavaScript.
Here is my understanding.
Java was designed to limit the damage that any developer could accidentally do, rather than maximize the potential for productivity. Which is an appropriate tradeoff for a large team.
It is hard to get good statistics on this, but the figures that I've seen in books like Software Estimation suggest that the productivity difference is around a factor of two.
This matters because it turns out that teams of more than 8 people have to be carefully structured based on the requirements of communication overhead. (A point usually attributed to The Mythical Man-Month.) This reduces individual productivity. Smaller teams can ignore this problem. The result is that measured productivity for teams of size 5-8 is about the same as a team of 20. But the throughput of large teams grows almost linearly after that. An army does accomplish more, but far less per person.
Limiting damage matters more for large teams. Which are more likely to be affordable for large enterprises. However being in such an environment guarantees bureaucracy, politics, and everything negative that goes with that.
By contrast startups can't afford to have such large teams. Therefore they are better off maximizing individual productivity so that they can get the most out of a small team. And using a scripting language is one way to do that.