3 companies headquartered in Ireland are in the RemoteWork directory. None of them has a live role on RemoteWork at the moment, but each company page tells you who to contact and what to say if you reach out anyway.
SaaS is the most common sector (2). Dublin is the most common city (1). Most common funding stage: Series B. Between them they have raised about $242M in disclosed funding; the best funded are Intercom ($242M).
1 of them hires from Nigeria or elsewhere in Africa. Headquarters is only where the company is registered; most of these hire remotely across time zones, so read each company page for where it actually hires.