Kotlin Professional Certificate
More study resources
Cheat sheet
Keep the key ideas within reach.
ExploreKey terms
Get comfortable with the vocabulary.
ExploreStudy plan
Give each week a clear focus.
ExploreCommon mistakes
Understand the traps and how to avoid them.
ExploreCase studies
Put your knowledge to work in context.
ExploreExam-day guide
Prepare for the day ahead.
ExploreAbout this exam
The Kotlin Professional Certificate is a JetBrains credential aimed at developers who want to demonstrate practical Kotlin competence. According to the source material, JetBrains positions Kotlin within a broader ecosystem of tools, libraries, and integrations for building modern applications, and IntelliJ IDEA is described as the IDE for Java and Kotlin. The exam's published domains divide evenly across four areas: Kotlin language fundamentals and coding tasks; object-oriented and functional Kotlin programming; the standard library, collections, and coroutines; and tooling, testing, and IDE-based verification. That last domain reflects how JetBrains frames learning itself: the JetBrains Academy plugin lets learners work through coding tasks and custom verification tests inside JetBrains IDEs, with instant feedback and a focus on learning by doing. Candidates should therefore expect a hands-on, code-oriented assessment rather than a purely theoretical one. Preparation should combine writing idiomatic Kotlin, practising collections and coroutine-based concurrency, and getting comfortable with IDE-driven testing and verification workflows. Note that the source material does not publish question counts, time limits, passing scores, fees, retake rules, or validity periods for this certificate; those details should be confirmed directly with JetBrains before booking. This page is independent study material and is not affiliated with or endorsed by JetBrains.
What you'll study
About Kotlin Professional Certificate preparation
Is this an officially recognised certification?
It is a JetBrains credential, so recognition comes from JetBrains' own standing in the Kotlin ecosystem rather than from a government or vendor-neutral body. This page is independent study material and is not affiliated with JetBrains. Check with JetBrains directly for current credential details.
How long is the exam and how many questions does it have?
The source material does not state a question count, time limit, or passing score for the Kotlin Professional Certificate. Rather than guess, treat these as unconfirmed and verify them on the official JetBrains page before you schedule. Plan your practice sessions around untimed coding tasks in the meantime.
What does the exam actually cover?
Four equally weighted domains: language fundamentals and coding tasks; object-oriented and functional programming; the standard library, collections, and coroutines; and tooling, testing, and IDE-based verification. The fourth domain means IDE fluency and test-driven verification are examinable, not just syntax knowledge.
How hard is it?
Expect professional-level difficulty. The even split across fundamentals, functional and OOP design, coroutines, and tooling means you cannot compensate for a weak area with strength elsewhere. Candidates who only write basic Kotlin, without coroutines or IDE-based testing practice, typically find the third and fourth domains hardest.
What is the most common reason candidates fail?
Weak coverage of the tooling and testing domain. Many developers study syntax and collections but never practise running, debugging, and verifying code inside a JetBrains IDE. Since JetBrains frames its learning tools around coding tasks and custom verification tests with instant feedback, practise that loop deliberately.
In what order should I study?
Start with fundamentals and coding tasks, then object-oriented and functional design, then the standard library, collections, and coroutines, and finish with tooling, testing, and IDE verification. The last domain reinforces everything before it, so leave time to rehearse complete coding tasks end to end.
Can I retake the exam if I fail?
The source material does not publish a retake policy for this certificate. Confirm retake rules, waiting periods, and any associated costs with JetBrains before booking your first attempt, and budget your preparation so a single attempt is realistic.
How much does it cost and how long is it valid?
Fee and validity period are not stated in the available source material. Do not rely on figures from older blog posts or forum threads, which may be out of date. Verify current pricing and any expiry or recertification requirement on the official JetBrains site.
How should I prepare in practice?
Write Kotlin daily rather than reading about it. Build small projects that use collections, lambdas, and coroutines, and write tests for each. Since JetBrains promotes learning by doing with instant feedback and quick results, working through coding tasks inside a JetBrains IDE mirrors the exam's emphasis on verification.
Do I need IntelliJ IDEA to prepare?
It helps. JetBrains describes IntelliJ IDEA as the IDE for Java and Kotlin, and the Academy plugin runs inside JetBrains IDEs, supporting Kotlin among other languages. Familiarity with IDE navigation, running code, and interpreting test feedback directly supports the tooling and verification domain.