Zerodha. They are the biggest stock broker in India with a team of less than 40 people. Check out their tech blog for their tech philosophy: https://zerodha.tech/blog/hello-world/
The zerodha post is ... hard to believe. Self managed _everything_ and one devops engineer, no SREs? Who's managing the self-hosted PostgreSQL instances with the hundreds of billions or rows of _financial_ data?
A lot can be said for having an engineering team with the experience and maturity to recognize both strengths and weaknesses of their technology choices.
They wrote a blog post about it but it's been a few years since I read it. IIRC it centered on the inherently stateless request model and how that interacts with the way they wanted to do concurrency.
