I think the words' metaphorical meanings don't help much unless you already know what they mean. If you heard the word "sharding" for the first time and all you knew was that it had something to do with computers, I think you'd have a hard time guessing that it means "partitioning rows of a database across multiple servers to reduce load".

In Polish literature, I saw "reflection" translated literally in programming book and it took me a while to even understand what the translator was trying to do.

Keeping loanwords is just simpler - we're going to learn them from English anyway.

Yes, but this goes for the English word too.

Sure there’s a Spanish word for shard though?