It would be hard to convince some people of this, because "everyone knows Spring is enterprise". Unfortunately many only have experience with legacy companies, bad code or through reading old blog articles, and base their opinions on that.
It's actually something you need to have experienced yourself to recognize the possibilities.
It may sound strange, but I enjoy going through the long list of projects in the Spring web site. I almost always find something cool and is surprised at how much they can simplify complex functionality
The learning threshold is also relatively low, because they tend to use common best practices in the framework.
I like Kotlin, but the lack of checked exceptions really kills it for me. Exception safety is a bigger thing for me than null safety.
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