The real difference isn't technical

Everyone thinks the junior → mid transition is about learning more technologies. It's not.

What actually changes

Juniors ask "how do I do this?" Mids ask "should we do this?"

The skills that matter

1. Reading code — you spend more time reading than writing
2. Breaking down problems — splitting a feature into tasks before touching the keyboard
3. Knowing when to ask — not too early (try first), not too late (don't waste a day)
4. Writing boring code — clever code is hard to maintain; boring code is easy to debug

The timeline

Most people hit mid-level between 18 months and 3 years. But it's not time — it's the quality of problems you've worked through.