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Mock interviews by role and level

Complete interviews, written the way a real interviewer runs them, with graded answers: what not to say, what merely passes, and what stands out.

Each question in this section has the same structure, because senior interviews rarely score you on being right — they score how you justify and what you are careful not to claim.

Layer What it is What it gives you
❌ What NOT to say The plausible answer that drops you a level, and exactly why it is wrong Spotting your own reflexes
⚠️ Acceptable answer The one that passes but does not stand out, and what it is missing Knowing where you are today
✅ Ideal answer The one that moves you up a band: mechanism, trade-off, number Knowing where you are going
🔁 Likely follow-up What they ask next, and how you handle it Not collapsing in round two

These answers are written to be said out loud. If an “ideal” one takes you more than 90 seconds, cut half of it: give the headline, offer to go deeper, and let the interviewer choose.

Role Levels covered Focus
🧪 QA / Test automation Junior → Staff/QA Lead Test strategy, automation, flakiness, quality as a process
⚙️ Backend Junior → Staff APIs, data, concurrency, resilience, production
🎨 Frontend Junior → Staff Rendering, state, performance, accessibility, UI architecture
🧩 Fullstack Junior → Senior End-to-end work and the seams between layers
🛠️ DevOps / SRE Junior → Staff/SRE CI/CD, Kubernetes, observability, incidents, cost
🏛️ Software architect Senior → Principal Trade-offs, integration, migrations, technical governance
🧭 Tech Lead Senior → Lead Decisions, delivery, people, and the technical side of leadership
Guide What it covers
By level: junior to staff The same questions, scored differently depending on the level you want
Leadership, conflict and influence Disagreements, unpopular decisions, mentoring, saying no
Recruiter screen, motivation and closing First screen, expectations, salary, your questions, the offer
  1. Pick your role and level (or the level you are aiming for: train one band above).
  2. Read the question only. Answer out loud, on a timer, before looking at anything.
  3. Compare yourself against the three layers. Most people find themselves in the ⚠️: correct, but with no mechanism and no trade-off.
  4. Mark every ❌ you have actually said. Those are your reflexes, and they are the first thing to unlearn.
  5. Close the loop: every question links to the course or bank question with the full theory.
Level What they expect from your answer
Junior Correct fundamentals, honesty about what you don’t know, demonstrable curiosity
Mid Autonomy: you solve things unsupervised and know the classic traps
Senior Trade-offs, data, production impact, deciding with incomplete information
Staff / Lead / Architect Scope beyond your team: systems, process, people, cost and risk

Levels are not universal: what one company calls senior, another calls mid. Use the table for calibration, not as a label.

Note: the mock interviews are fully available in English. The question bank and the courses are still in Spanish — you will see a notice on those pages. Contributions welcome.