I've found a career ladder helpful for structuring my professional development and making promotion discussions more objective.
Buffer is generally open with their corporate policies. Here's Buffer's ladder.
Here's a simple example:
|1||Executing delegated tasks||Individual|
|2||Proposing tasks required to build product features||Team|
|3||Coordinating development for a product area, eg architecture||Org|
|4||Coordinating development for all product areas, eg CTO||Company|
|5||Coordinating tech across companies, eg Fellow||Industry|
Each rung is broadly defined and would have an associated compensation range, eg "pay band", providing room to grow.
Given such a ladder, employees can perform their own career planning, review peers' performance against self-assessments based on a common structure, and initiate discussions regarding promotion based on an objective measure.
Related, although there are management aspects to senior IC roles, I'm a fan of maintaining a distinct ladder for IC and management. ICs manage projects. Managers manage people. They collaborate continuously, but are evaluated differently.