Linchpin is a small pin that keeps various parts of a wheel together.
In our world, we call them as humans that are indispensable to an organisation.

While a linchpin does a lot of paddling like the duck, there are some things that they categorically always do: 

Owning the job: If it is the job of someone in the company, it is the linchpin job. No job is small or insignificant. Having the courage to do it and get the team along is what makes them indispensable.

Don’t require follow up: If a linchpin owns a job, they own it completely. We won’t be required to follow up with them, and when they are running late, they will be the first to inform.

Owning outcome versus output: Output is what is required from us. Outcome is the magic we create beyond what is required from us. Owning the output is having to do the task, owning the outcome is wanting to do the task. Linchpins sign up for the latter because their work signs for them.

It turns out, rewards and accolades alone don’t make linchpins.
Being a linchpin is a choice, the competition is scarce, and we make that choice each day as who we are.