Ask HN: As a freelancer, how can I help a junior team?

As a freelancer, what can I actively do that doesn't incur too much overhead on the junior developers, but can still support them in their work and career?

Background: I'm a self-taught web developer, doing freelance for about 8 years now, I've worked with about 10 companies (anything from 1 month to 12 months at a time) and have also created a mostly-automated revenue-generating side-business.

In my current project I'm placed in a very junior team. They're all good coders, but for many of them, it's their first job after university.

I'm trying to figure out, how I can best help the team. I do pair programming with several of them. I try to crank out some features, but their domain knowledge is higher and the codebase is very large, so my efficiency is limited. I've done a workshop to get more out of their IDE (JetBrains tools in this case) and they liked it.

ADDED: Am not in a managerial position. I was asked to help develop features as freelance developer, but after a month, the project manager had asked me if I can also help the team in a more mentoring / coaching role.