Provyn Prep · React competency
Rendering & state in the React assessment
Rendering & state is one of the areas a Provyn React credential scores separately, so a recruiter can see it on its own rather than averaged into one number. This guide explains what it covers, how it is tested and what to practice.
What it covers
When and why components re-render, reconciliation and keys, JSX, forms, where state should live, and typing props.
Topics in the practice set for this area
- rendering / reconciliation
- JSX
- forms
- state management
- rendering / pitfalls
- rendering / batching
- TypeScript props
How it is tested
In the timed assessment, questions in this area use these formats: multiple choice, put the steps in order, short answer, written scenario. Each attempt draws its own set of questions, and this area gets its own sub-score on the credential when the attempt includes enough questions from it. The assessment questions themselves are never published; the practice set below is written separately for study.
What to practice
- Predict how many renders a state update causes, including batched updates.
- Build a controlled form with validation and lift its state to a parent.
- Explain what happens when list keys are array indexes and items are reordered.
Try a practice question
From the free practice set (10 questions in this area). Answers and explanations are in the practice set.
- Why must every list child have a `key`?
- JSX `<Foo prop={value} />` compiles roughly to:
- Controlled input means:
Practice before the real thing
Both are free and use practice questions only, never questions from the real assessment.
More React study guides
Last reviewed 2026-10-06.