Clojure was made with databases and concurrency in mind. We've used it at previous startups, projects, and find it a productive language.
Also the clojure community is amazing. The clojurians slack is one of the most helpful communities for solving hard problems. Stopa will be giving a talk at at the conj later this year [1]
Why not the standard node.js with shared module? Assuming performance is not the primary goal.
Why not generated rust structures from model file and a rust server? Assuming performance is the primary goal.
Why not a jvm with a lightweight runtime? (Assuming instancing is used for scale here, a lot of wasted ram usage here)