Comment by sally_glance

Very interesting topic and as you say the ratio should very much depend on what his designated role in the team was.

For tech leads, I think the ratio should be heavily skewed towards enabling other team members (by pairing or working on cross-cutting concerns, usually devops/infra). Something like 20/80, where the 20% individual contributions are only the toughest nuts which can't be done in a reasonable timeframe by anyone else.

For senior developers, I'd say it depends on team composition. If there is one senior and 3 juniors, training them should be his primary concern. If there are 5 heavily specialized seniors, I'd say the ratio should lean towards individual contributions.