fixer; dispute resolution specialist
Refers to a person who resolves problems or disputes, often behind the scenes, sometimes with a slightly shady or informal connotation. Not a formal job title.
He is known as a fixer in the industry.
I asked a fixer to resolve the trouble.
Compound of 事件 (incident, case) and 屋 (shop, person who does something as a trade). The 屋 suffix here indicates a person who deals with incidents or disputes professionally or habitually.