In addition to other answers: Java absolutely does have the qualities necessary for startups, so using it for new projects makes sense.
1. Modern frameworks and AI assistance can help ramping up a decent backend in days. Solo tech co-founder needs to know only Java or Kotlin and some frontend stack to build MVP quickly and will spend such amount of time on non-coding tasks where language features will be irrelevant. Swift can be the second language if you go mobile-native.
2. Scaling isn’t the problem you are going to have for quite a while. It is quite likely, that problem of scaling the team will come first and any performance bottlenecks will be noticeable much later. Java is good for large teams.
That said, from business perspective, if you want larger talent pool, fast delivery cycles and something that may remain as your core stack in the long term - Java or Kotlin is probably the best choice. If you want fancy tech as a perk to attract certain cohort of developers or you have that rare business case, you can choose Go or Rust. Python is popular in academia and bootcamps, but TBH I struggle to see the business value of it for generic backends.
1. Modern frameworks and AI assistance can help ramping up a decent backend in days. Solo tech co-founder needs to know only Java or Kotlin and some frontend stack to build MVP quickly and will spend such amount of time on non-coding tasks where language features will be irrelevant. Swift can be the second language if you go mobile-native.
2. Scaling isn’t the problem you are going to have for quite a while. It is quite likely, that problem of scaling the team will come first and any performance bottlenecks will be noticeable much later. Java is good for large teams.
That said, from business perspective, if you want larger talent pool, fast delivery cycles and something that may remain as your core stack in the long term - Java or Kotlin is probably the best choice. If you want fancy tech as a perk to attract certain cohort of developers or you have that rare business case, you can choose Go or Rust. Python is popular in academia and bootcamps, but TBH I struggle to see the business value of it for generic backends.