The Invisible Promotion: How to Go From Mid-Level to Senior Developer x

You’ve been coding for years, but something feels off. You’re not a junior anymore, but you’re not sure you’re senior either. Titles are blurry, expectations unclear. This guide breaks down what separates mid-level from senior engineers — and how to make the leap

Who’s Really Mid-Level vs. Senior?

There’s no strict line between mid-level and senior developer, it’s not an official term. However, usually when people talk about these skill levels they have some expectations and there’s some level of agreement on what they represent, but it’s rather a scale, and it changed since the emerge of AI and role inflation. I’ll describe the real role descriptions here, not the inflated ones.

Hi! I’m Tom Smykowski, a Software Engineer with 10+ years of experience. I’ve led frontend teams, built design systems for $1B+ companies, mentored devs at all levels, and reviewed thousands of lines of code, portfolios, and resumes. I know what gets people hired — and what makes them thrive.

In the technical path we can distinguish four roles: junior, mid, senior and principal engineer. Junior is someone who just started work, or works for several years, mid developer is someone who worked for several years already, senior has a longer tenure, while principal engineer already worked for a long time. I’d say junior is between 0–4 years, mid: 5–9 years, senior: 10–15 years and principal: 15+ years of experience. One thing to notice here is that everyone assumes other periods of time, and there are cases where such ranges don’t apply, and it’s because formerly mentioned role inflation.

From the task handling perspective junior developers need a lot of help and guidance on every task, down to basic things like programming languages, frameworks operations. It doesn’t necessarily mean they need to ask for people help, because now we have AI too, but they have to research and learn on almost every step of the work. If it comes to AI usage, they use it, but the generated code is usually unacceptable, because they can’t due to lack of knowledge and experience know if the generated code is proper or not. So they need also heavy guidance towards using AI-assistive techniques more of a learning booster than replacer.

The full article is available on my blog.