IC vs Manager: First 90 Days, Compared

The phases are the same: learn, contribute, deliver. The bar moves dramatically.

For an IC, the first 90 days end with one shipped artifact attributable to you. A merged feature, a closed bug list, a design that went live. Output is your work.

For a manager, the first 90 days end with a calibrated team. Your direct reports know what you expect, you know how each of them is doing, and at least one team-level decision has been made and communicated. Output is the team's work, made better by your presence.

The biggest mistake new managers make is acting like a senior IC for too long, because IC work feels productive and managerial work feels intangible. By day 60, if you are still primarily delivering individual contribution, you are behind. The team noticed in week 4 even if you have not.

The biggest mistake new ICs make is performing managerial scope before they have shipped a small thing. Big-picture commentary in week 3 reads as confidence; in week 8 it reads as a way to avoid the work. Ship something small first.