I'm like him, senior developer at a small company (~80 people total, 15 in software dev) and also do all those things.
Sometimes I am team lead or tech lead for a while, then purely dev for a while, depending on what projects we have and how we are divided into teams at the time.
It's not considered "higher", just a role that the seniors sometimes have.
The only job title above "senior x" in the company is Director.
That's perhaps because it is a very small team but it's highly unusual in larger organisations.
In general "senior engineer" is actually a rather junior level in the overall organigram. 5 years experience doing pure dev. and your title is bumped to "senior engineer" but you're still a 'only' a dev.
Sometimes I am team lead or tech lead for a while, then purely dev for a while, depending on what projects we have and how we are divided into teams at the time.
It's not considered "higher", just a role that the seniors sometimes have.
The only job title above "senior x" in the company is Director.