this is perhaps controversial but i actually think datomic is so powerful, it's worth using clojure for. in other words, the database is driving the choice of programming language.

the idea of viewing a database as an immutable state of the world at a given instant t0, and time becoming a parameter on that state of the world (in order to show changes as time goes forwards [or backwards!]), is extremely, extremely attractive for things like finance, whose first class citizens are among others:

- capability for audits e.g. show me the history of transactions from any particular account. since datomic is basically a collection of immutable facts over time, this is "free"

- distributed computing - datomic runs nicely across your own internal compute (often needed for financial stuff)

- transactions are no longer strings, but are actual data structures - this makes the gnarly steps of things like transferring assets across instruments a lot easier (i'd imagine). think about how you'd implement a shopping cart with transactions in postgres vs. how you'd do it with access to raw data structures