Why does Segment have a large Go code base? From my oustider perspective it would seem to be mostly client side javascript plus server side glue code. And big

Why does Segment have a large Go code base? From my oustider perspective it would seem to be mostly client side javascript plus server side glue code. And big data glue is best written in Python. Now, of course, Segment may be big enough to have many large codebases and Go is just one of them.