This is enormously helpful. And it’s a great question.

‘Turn your hierarchy to an advantage’ is the point that resonated with me most! Done right, I think the opportunities for self-development at a startup eclipse those at a large company, since there are so many more opportunities to take responsibility, make a mess, clean it up, and do a better job next time!

A couple of things that I found have also helped:

• Picking up from ‘Encourage team members to reach out beyond the company to learn’ — I’d suggest that realistically the onus is on the senior people to bring those external people in. Junior people don’t have the network, or the awareness to know which areas they’d benefit most from. At Big Health I brought in old friends who were domain experts (e.g. infosec, sysadmin, iOS deployment) at strategic moments to act as tutors for my hungriest junior employees. They’d have 1h sessions together (a little like an Oxbridge tutorial), usually screen-sharing, talking through a particular piece of infrastructure or problem or technology. Even just one of those every fortnight or so was like pouring gasoline on a fire for their technical development, and they really appreciated it. Depending on the area, I can potentially recommend some tutors.
• At C4: if you have more than 3 or 4 people, that’s enough to run a Journal Club every fortnight or so, where one person brings a paper/article to discuss (along with a few quick introductory slides perhaps), everyone reads it in advance, and then you have a discussion. For extra points, occasionally invite someone from another company in the late afternoon then go for beers together.
• At C4: we run special Training Days, often off-site. We’ll run a coding kata (where everyone tries the same coding exercise, then we swap and review and discuss each other’s solutions), a tutorial on a particular deep topic, then a collaborative game/hackathon in the afternoon. These are pretty time-consuming to set up. But when I took over a relatively young team of a dozen people, I took the view that it was worth days of my time making these be good if there was a chance of making everyone else even 10% more productive. Over the course of the first year of running these every 6 weeks, I’m positive it made a much much larger difference than that. [I’m now in the happy position that my senior team members are running the Training Days for the next generation, and I think both sides are learning from that experience!]

- Also, well-run retrospectives can do a lot to help people learn from their mistakes in a safe way…

Such a great topic!

Finally, this was the piece that convinced me it was my job:

https://a16z.com/2010/05/14/why-startups-should-train-their-people/