> Keen, Sendgrid, Stream all started out with Python and switched later on. SendGrid engineer here. IIRC, each of the three founders wrote components in the l

> Keen, Sendgrid, Stream all started out with Python and switched later on. SendGrid engineer here. IIRC, each of the three founders wrote components in the language that they were most productive in at the time. So there were services in Python, Perl, or PHP depending on who wrote it. Seems like a solid strategy to take the fastest path to MVP when you're still trying to prove there's a market for what you're building. As the company grew, Python emerged as the most commonly chosen language for new projects. As you said, the initial appeal of Go was its performance. An occasional side-effect of "fast" is needing less hardware to do the same work, so its efficiency was also attractive. I think a key moment that got us interested in Go came at an internal hackathon. One of our engineers built a prototype replacement for a core piece of our MTA. It was something like 6x faster than the existing Python version. The ability to produce that in such a short period of time demonstrated that Go was also a surprisingly productive language. These days, most of our engineering teams choose Go for new backend services -- even those that aren't performance-sensitive. However, we still have a lot of active development in Python (and Ruby). Disclaimer: I've been at SendGrid about 4 years, so some of this is second-hand. I'll ask the founders if they're up for doing an article on our engineering blog about it.