"건축물 기록보관사" is the term you are looking for, provided you have an official certificate/license issued by the government or an institution. The suffix ~사 is indicative for this certificate. 의사: doctor 간호사: nurse 변호사: lawyer; attorney 판사: judge 검사: prosecutor

There would be a direct translation like 건축 아키비스트, but I should have looked for a dictionary to find out what 아키비스트 is. 아키비스트 is just a loan word from English. 건축 means the field of architecture and is very well known. There's no problem with architecture. Can you consider yourself as a curator? If you can, you can say you are a 건축 큐레이터, which translates to architectural curator. If not, I'm sorry and I didn't intend any offense. 큐레이터(curator) is somewhat known, at least when compared to archivist. If you are not satisfied with any option, you can just say where you work at, like 박물관(museum) or some company name. I think 건축 아키비스트 is appropriate in professional context. For other contexts, it's your choice.