Software leveling is a complicated debate. What is a “Junior” Engineer? At what point is someone “Senior”? Every company has a slightly different outlook on this, and this is just my opinion; it’s the mental model I use.
Junior Software Engineer
As a Junior Software Engineer, an individual would be primarily getting small-to-medium tasks delegated by their manager (or team lead). The expectation should be that this engineer will require assistance with these tasks as they become familiar with the environment, tools, and grow into their role. At the end of this level, the individual should be able to fully accomplish their assigned tasks on their own, and beginning to own the delivery of larger features. There should be no expectation of expertise in engineering (or the tech, tools, and resources available), and no expectation of familiarity with the environment.
At the level of a Software Engineer, the individual should be capable of receiving and delivering on a full feature. They should be able to accept a spec for a new feature and deliver on it with minimal assistance. They should be growing a level of expertise and knowledge of the technical space that they operate in.
Senior Software Engineer
At the level of a Senior Software Engineer, the individual should be fully autonomous within the scope of their team/project within the organization. They should be capable of receiving a problem statement, figure out what to do, and deliver a solution that address the issue with minimal oversight necessary. They should possess a solid understanding of the technology they are using, the ecosystem around it, and be trustworthy to balance the pros and cons when making decisions.
Staff Software Engineer
The Staff Software Engineer level tends to be where expectations diverge. I expect a Staff Software Engineer to be capable of addressing problems which impact multiple areas of the organization. They should be considered to be responsible for (or significantly contributing to) setting the technical direction of the organization. They should have a high-level view of much of what is going on outside of their team, deliver on goals that have a wide-spread impact, and reduce intractable problems to addressable tasks. As such, a Staff Engineer should have an in depth understanding of the organization they are working in, outside of the scope of just their team. This means that typically I would expect someone to be promoted to this level internally only. It would be exceptionally difficult for someone to be successful at a Staff Engineer level without a pre-existing familiarity of the environment that they are working within.
Note that my opinions on this topic are liable to change. If changes are made, I’ll include a record of changes.