Bitcoin library vs script to develop application

[Bitcoin]

Bitcoin library vs script to develop application

I'm curious about the development of application of Identity management in Blockchain platform, but I'm a bit confused about the technologies to use.

In short words, when is more convenient to develop an application coding in script and when is it better to use a high-level library like BitcoinJ or a service as Blockchain.info API?

I'm a Java developer and I'm more confortable using a Java Library like bitcoinJ, but I don't understand if, in this way, I can lose something in performance or expressivity or "semantic power" in regard to most raw-level scripting system of Bitcoin (that is a kind of assembler).

Thanks you in advance

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