[EternalAugust]

Not "front end" (I assume you mean stuff like React) but many of these are candidates for coding tests in interviews: http://rosettacode.org/wiki/Category:Programming_Tasks

Though some would take longer than 45 minutes.

archived version from feb 2019 since cloudflare dns seems to be broken atm: https://web.archive.org/web/20190219135427/http://rosettacod...