Как правильнее транслитерировать/перевести имя Jian-Yang ? (персонаж из "Silicon Valley")
Если это пиньинь, а похоже на то, тогда
Цзянь Ян, если это фамилия и имя, или
Цзяньян, если это имя
Подкрепляя цитатой из таблицы перевода пиньиня в систему Палладия
jian — цзянь
yang — ян
As for the question in comments: not too many versions to guess the name meaning. Some real people with such a name/surname are written in Chinese as 杨健 (Yáng Jiàn, 2nd and 4th tones). The first character is known to be used as a surname (dictionaries say so), but it also has the meaning 'poplar'; the second character means 'healthy/strong'. Examples from wiki: https://en.wikipedia.org/wiki/Yang_Jian_(footballer) ; https://en.wikipedia.org/wiki/Yang_Jian_(diver) .
If a person of Chinese origin lives in a Western country, the original surname+name order is often reversed into name+surname: https://en.wikipedia.org/wiki/Jian_Yang_(politician) - same could be with the film character.
There were also historical Yang Jian persons with the surname 杨 who had different name part 暕 (Jian, 3rd tone - bright/light) https://en.wikipedia.org/wiki/Yang_Jian_(Sui_prince) and 堅 (Jian, 1st tone, strong) https://en.wikipedia.org/wiki/Emperor_Wen_of_Sui .