Ask HN: What is the next step in a software engineer's career?

I have been a software engineer for 25 years, I have acted as a CTO for equity only startup, but I'm at a company now where I can define my own job title. Non-executive. The founder suggested I be a "Director" level, but as a software engineer, I feel more like "Architect" or something like that. He said "Principal Engineer" was too low of a title for me. What tech job titles indicate expertise in a stack?