A level is not a list of technologies. It describes the scope a person can handle, the quality of decisions they can explain, and the evidence they can produce under realistic constraints. Use this matrix to calibrate practice or structure a human review—not as an automatic hiring decision.
Junior: reliable work with bounded scope
- Explains core JavaScript, browser, HTML, and CSS behavior using a concrete example.
- Clarifies a small feature contract and implements a readable solution with guidance.
- Checks a success case and responds constructively when a failure is identified.
- Communicates what is known, what is uncertain, and where help would be useful.
Mid-level: independent feature ownership
- Connects technical choices to user behavior, maintainability, accessibility, and delivery constraints.
- Owns an ambiguous feature from clarification through implementation and verification.
- Recognizes common async, state, rendering, data, and failure-mode risks before they become incidents.
- Explains tradeoffs without treating a familiar framework or pattern as the only valid answer.
Senior: system judgment and leverage
- Frames a problem through quality attributes, boundaries, operational risks, and the needs of multiple contributors.
- Diagnoses performance and reliability problems with measurement before proposing optimization.
- Designs migration, observability, testing, accessibility, and failure recovery as part of the solution.
- Raises the quality of a team through clear decisions, review, mentoring, and cross-functional communication.
Staff+: organizational scope and durable direction
- Defines contracts that let multiple teams move independently without fragmenting the user experience.
- Balances product outcomes, platform investment, risk, migration cost, and long-term ownership.
- Creates feedback loops and guardrails rather than relying on personal review of every decision.
- Explains when standardization is valuable, when local autonomy is safer, and which evidence should change the strategy.
How to use the matrix responsibly
- Choose a target level before the interview and translate each expectation into observable prompts.
- Record supporting, counter, and missing evidence separately; do not convert silence into a midpoint score.
- Compare evidence with the actual role rather than a generic title.
- Use the matrix alongside human judgment, accommodations, job relevance, and the complete selection process.
Editorial review
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