noun, noun which may take the genitive case particle 'no', na-adjective
well done; excellent result; great job
Used to praise a result or performance that exceeds expectations. Often used as a standalone exclamation or with な/の to modify a noun.
今日のプレゼンは上出来だった。
Today's presentation was a great success.
初めて作ったケーキにしては上出来だ。
For a first attempt at making a cake, it turned out really well.
上々 also means 'excellent' or 'very good', but is more often used for conditions or states rather than concrete results.
Compound of 上 (じょう, 'upper, excellent') and 出来 (でき, 'result, outcome').