CASE FILE · COHORT 2025 - 2026
Daniel Jankowiak
// FullStack Software Engineer · Cracow, Poland 🇵🇱
THE STORY
Daniel’s Path To Senior
- 01
Daniel was stuck in the loop: doubt your skills, botch the interview, doubt them more.
- 02
He broke it with evidence: JavaScript, architecture, testing. Rebuilt and verified, piece by piece.
- 03
Confidence with something real under it.
- 04
New full-stack role in Cracow. 'My mind is much, much better.' His words.
WHAT DANIEL MASTERED
I'm much more confident about my skills and my mind is much, much better.
Find Your Gaps To Senior.
20 minutes, zero fluff. Test yourself on the same dimensions Daniel mastered — and get a breakdown of exactly what to work on next.
Your Skill Breakdown
THE OUTCOME
What changed at Senior level
Landed a new role
New confidence & clarity
IN DANIEL’S WORDS
“I’m much more confident about my skills and my mind is much much better.”
THE SENIOR JOURNEY
The senior skills Daniel built
Getting to senior isn’t about learning another framework. Daniel’s path covered the dimensions that actually move an engineer up a level — the same areas theSeniorDev coaches every member through:
System Design & Frontend System Design
Daniel learned to lead system design and frontend system design discussions — scalability, data flow, and architecture trade-offs — the conversations that separate a senior fullstack software engineer from a mid-level one.
Technical & Live-Coding Interviews
Instead of memorising answers, Daniel built a repeatable process for technical interviews, live-coding challenges, and take-home tasks — shipping production-ready solutions under pressure.
Fundamentals: Testing, Performance & Software Architecture
Daniel went deep on the senior fundamentals — testing, performance, and software architecture — and the mental models that outlast any framework or library.
The Full Software Lifecycle: Backend & Cloud
Moving beyond the framework, Daniel grew across the full stack — backend and cloud — to deliver end-to-end and become the go-to engineer on the team.
Selling Yourself & Communicating Senior-Level Value
Daniel learned to communicate real engineering value — a senior-level CV, LinkedIn, and STAR interview stories — so the level showed long before the offer landed.
Free Senior Training.
One session, the whole system: the fundamentals, the interview strategy, and the plan Daniel followed to the offer. Watch it free.
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