Not OP, but I would venture that REPL-driven development encourages a style that is essentially trial and error programming. This may be good for small scale,

Not OP, but I would venture that REPL-driven development encourages a style that is essentially trial and error programming. This may be good for small scale, short lived scripts and projects but it does not scale. My experience from a somewhat large (400+ people) Clojure project is that people would be better off building a test suite as a checked-into-source-control REPL substitute to drive their experiments and make sure the expected application behaviour stays the same over time. REPLs may be useful, but don’t use them as your only tool.