I'm not sure how the agency is structured - but what I can vouch for (and seen work) is continuous communication amongst coworkers in the form of tech talks and

I'm not sure how the agency is structured - but what I can vouch for (and seen work) is continuous communication amongst coworkers in the form of tech talks and documentation. That way, knowledge is distributed within the team and a situation like this is avoided upfront. I'm reminded of the Bus Factor concept: https://en.wikipedia.org/wiki/Bus_factor https://en.wikipedia.org/wiki/Bus_factor