[atoko]

You are supposed to modify and fit Agile into your specific process, not follow it dogmatically. It's literally the first thing on the manifesto: "Individuals and interactions over processes and tools". Change the process, or change the culture around this instead of blaming a broken process.

To add an example: At this company they have the concept of an IP (Innovation and Planning) sprint. This means that one sprint out of 5 we take to fix technical debt, add instrumentation, verify documentation. You should have some time carved out for mentoring.

At the very least, don't count the juniors in your capacity. This way you'll be able to handle their pace while keeping your velocity.