You can refer to an unsophisticated but fairly effective solution to a problem as a kludge. Kludge is used especially to talk about solutions to computing problems.
kludge in British English
(klʌdʒ)
noun
informal
an unsophisticated but fairly effective solution to a problem; esp a computing problem
People outside of AI sometimes detect a programming kludge.
kludge in American English
(kludʒ) or kluge (kludʒ)
noun Slang
1.
a piece of computer hardware or software, or a computer system, that is clumsily designed or improvised from mismatched parts