Realistically, "good enough for Google" is probably largely an accident of acquisition. QPX, the low airfare search engine, is not exactly a small piece of software. In c. 2007, it consisted of about 1 million lines of code divided unevenly between Common Lisp and C++, which, by then, had been developed for roughly a decade for the airline industry. Rewriting it would have been a non-trivial task.
Furthermore, Carl de Marcken, chief scientist/co-founder of ITA, had chosen Lisp because it was what he was most familiar with. He had told me in 2007 that if he had to choose a language again, he probably would have chosen Java, a choice Google would likely favor over Lisp.
I say this not to disparage Lisp—I enjoy Lisps, and I use Lisp professionally—but to contextualize this particular use of Lisp at Google.
EDIT: Just saw your reply to a sibling comment explaining that you meant SBCL, not Lisp per se.
Furthermore, Carl de Marcken, chief scientist/co-founder of ITA, had chosen Lisp because it was what he was most familiar with. He had told me in 2007 that if he had to choose a language again, he probably would have chosen Java, a choice Google would likely favor over Lisp.
I say this not to disparage Lisp—I enjoy Lisps, and I use Lisp professionally—but to contextualize this particular use of Lisp at Google.
EDIT: Just saw your reply to a sibling comment explaining that you meant SBCL, not Lisp per se.