Android Interview Prep: Q&A

Interview Helper is a trainer for Android developer interviews: 3,270 questions with in-depth answers, code puzzles, a study plan built around your interview date and an honest readiness score. Works fully offline.

Please note: the questions and answers are currently in Russian. The app interface is available in English, Spanish, Portuguese, Ukrainian and Russian.

HOW AN ANSWER WORKS
Try to answer out loud first, then reveal the answer:
• TL;DR — the gist in 1–2 sentences, the thing to say first
• A detailed walkthrough with code samples
• Common mistake — where candidates usually slip
• What they ask next — the interviewer's follow-up questions

12 TRACKS
Java · Kotlin · Android · Architecture & DI · Networking · Performance · Security · Kotlin Multiplatform · System Design · Algorithms · Tooling · Soft skills

Answers are checked against current versions: Kotlin 2.4, Java 25, Android 16, Compose, AGP 9 and Gradle 9, OkHttp 5, Retrofit 3, Ktor 3.

290 CODE PUZZLES
"What does this print?" and "Find the bug" for Java, Kotlin and Android — just like live coding. Pick an option and see the explanation right away.

A PLAN FOR YOUR INTERVIEW DATE
Set the date, the position level and the tracks, and the app spreads the questions over the days. Every day brings a portion of new questions plus review, weakest sections first.

SPACED REPETITION
Mark "I know it" or "Review later" and spaced repetition brings a question back just as you start to forget it. A daily goal, a day streak, reminders and a "Question of the day" widget help you practice a little but often.

INTERVIEW READINESS
See how ready you are for Junior, Middle or Senior and which weak spots to work on first.

MOCK INTERVIEW (PRO)
Random questions, a timer for each answer and an honest self-rating. At the end you get a report by track and a mistake review.

ALSO
• Search across questions and answers
• Bookmarks and an "I was asked this" mark
• Junior, Middle and Senior levels
• Dark and light theme

FREE AND PRO
Free: every Junior question plus two Middle and two Senior questions in each section — over 1,200 questions — along with search and bookmarks. Pro unlocks all 3,270 questions, mock interviews, and new questions and tracks. Choose a monthly or yearly subscription, or a one-time lifetime purchase.

Found a mistake in an answer? Tap "Report" right on the question card and we'll fix it.

Recent changes:
Большое обновление 2.0:
• Приложение полностью переписано: новый дизайн, тёмная и светлая темы
• Тысячи вопросов по Java, Kotlin, Android, архитектуре, KMP и System Design с уровнями Junior/Middle/Senior
• План подготовки к собеседованию и оценка готовности
• Пробные интервью с уточняющими вопросами
• Задачи на код и интервальные повторения
• Вопрос дня, виджет и напоминания
• Pro-версия с полной базой вопросов