Short answer: it depends on the platform, and each one decides this itself. Here is what the site's data shows for the ones that fit Arabic medical work.
Mercor: after you apply you do a ~20-minute AI video interview (desktop Chrome, camera on) and sometimes a written assessment, then a work-authorization check. Hearing back usually takes 2 to 4 weeks, with no specific feedback. Approval puts you in a talent pool, not on a project: you still need to be matched to a client contract, and paid work is weekly. Take the free practice interview first.
Alignerr: some roles add a skills assessment, a voice sample or a Zara AI interview. If Zara shows on your dashboard, it is required, and language roles may also get a human check of native-level skill. Alignerr publishes no timeline. Once matched, you verify your ID with Persona and connect Stripe or PayPal. Pay is weekly. Passing does not guarantee a project.
Nothing on our record rules out Egypt for either, but each role states where it takes people from. DataAnnotation only takes workers from six countries, Egypt not among them, so I'd skip it.
If you've applied to either, please tell us how long it took you to hear back and what the interview was like. That's the part the platforms don't publish.