What is the difference between a junior, mid-level, and senior developer?

This is one of the first questions many developers ask themselves when starting out in this profession.

The answer is both simple and complex...

Simple, because some people (often recruiters) simply attach a number of years of experience...

But in reality, the answer is complex because there is no official framework, and everyone has their own evaluation and view of things.

That's why today we're going to give you our version of these profiles, of what differentiates them, trying to align as much as possible with today's market vision.

The 5 levels of experience

We often start from the assumption that there are only three levels of experience, because that's what's done in other professions.

But the developer profession isn't exactly like all other professions

You can practice this job with very broad but fairly shallow skills, or develop a particularly deep expertise.

The 5 levels of experience as a dev that we're going to talk about are: beginner, junior, intermediate, senior, expert.

Beginner

When you start out in this profession, you learn programming, you learn basic concepts and how certain systems work.

You have no experience, neither professional nor even on a concrete project, and even knowing how to program, you still lack the tools to enter the job market.

While training, most of the time, you're still a beginner!

Junior

A junior developer is capable of contributing to a real, professional project, but will still need to be supported in their learning, in solving certain problems, and in best practices.

What characterizes a junior dev is the inability to be truly autonomous due to a lack of professional experience

This is a period where continuous learning of skills and tools not covered in initial training is crucial!

Intermediate/Confirmed/Mid-level

Once you start becoming autonomous on projects, instinctively avoiding certain mistakes and developing genuinely good practices in software design, then we can talk about a confirmed developer!

You're also (generally) much more comfortable with teamwork as well as with project management and time estimation.

Sometimes this is discussed in terms of 2 or 3 years of professional experience, but it depends a lot on each individual and their work environment...

Senior

Depending on the field, we talk about a senior developer after 5 to 7 years of experience (even 10...), but what really matters is the scope of skills acquired.

A senior must be able to make well-thought-out technical choices, anticipate certain pitfalls and constraints, and mentor other developers to help them level up their skills.

Senior profiles are notably found in positions such as Tech Lead or CTO (Technical Director).

Expert

Expert is a slightly different profile, because it's not necessarily a natural progression: not everyone necessarily becomes an expert.

We advance our expertise in various technologies (languages, tools, frameworks, etc.) throughout our career, but only some devs focus enough on one particular technology to know its ins and outs and how it works in detail.

You can be senior, develop broad skills, and never develop expertise on a particular subject!