Comment by grumpy8

IMHO the biggest reason to use TypeScript rather than Reason is because, in the end, it's still javascript and it stays within the same ecosystem. As great as Reason is, it's adding too many dependencies. The only time I'd go with Reason instead of Typescript is if the developers on the team are already proficient with OCaml. It's going back to the "Use boring technologies even though some things suck as it's better to deal with known issues than unknown issues; the grass isn't always greener with new technologies, just different things that suck".