When one person is the safety net, you don't have a team.

There's a pattern I see in almost every team that's grown faster than its structure. One senior person reviews everything. Unblocks everything. Owns the architecture. Gets pulled into every incident, every tricky client call, every hiring decision. From the outside, it looks like strong leadership. From the inside, it's the entire business held together by one person's calendar.

That's not a team. It's a single point of failure with helpers.

The tell is what happens when that person takes a week off. Decisions stall. Work piles up waiting for review. Juniors freelance in directions they shouldn't, because the person who would have caught it isn't there. By the time they're back, there's a queue, and they spend the next two weeks clearing it instead of doing the work only they can do. The cycle continues until they burn out or leave — and then the structural fragility becomes a structural crisis.

The instinct is to "support them" with more juniors. That makes it worse. Juniors generate review load; they don't reduce it. The actual fix is harder: identify the specific work that currently only one person can do, and make it doable by at least one other person. Sometimes that's a senior hire. Sometimes it's documentation and decision rights, so the calls don't have to come back to one desk. Sometimes it's removing the work entirely — the meeting, the approval step, the report nobody reads.

Here's the test I use: pick your most senior person and ask what would actually break if they were unavailable for two weeks. If the honest answer is "a lot, quickly," that's not a tribute to how good they are. It's a description of where your business is fragile.