If you're looking for alternative ways to say "work for," there are several good options. One option is "serve," which suggests a more altruistic motivation for the labor in question. Another possibility is "support," which emphasizes the role of the worker in assisting a particular goal or objective. "Collaborate with" can also be a good choice, as it suggests a more equal relationship between the worker and their partners or colleagues. Ultimately, the choice of synonym will depend on the context and tone of the sentence in which it is used, so it's worth considering your overall message before making a final selection.