Junior

What they look for

Evaluation

• Correctness of the solution.
• Efficiency of the algorithm (time and space complexity).
• Code clarity and readability.
• Problem-solving approach.
• Understanding of data structures and algorithms.

Sample questions

• Given an array of integers, return indices of the two numbers such that they add up to a specific target.

  ArrayHash MapTwo Pointers

• Implement a function to check if a binary tree is a Binary Search Tree (BST).

  TreeRecursionBST

• Find the kth smallest element in an unsorted array.

  ArraySortingHeap

• Write a function to determine if a string is a palindrome.

  StringTwo Pointers

Prep for this round

1. 01Practice coding problems on platforms like LeetCode (Easy/Medium).
2. 02Review common data structures (arrays, linked lists, trees, graphs, hash maps) and algorithms (sorting, searching, BFS, DFS).
3. 03Understand Big O notation.
4. 04Practice explaining your thought process out loud while solving problems.
5. 05Be prepared to write code on a whiteboard or shared editor.

Common rejection reasons

• ×Incorrect or inefficient algorithm implementation.
• ×Inability to explain the time/space complexity of their solution.
• ×Difficulty with basic data structure manipulation.
• ×Poor coding style or syntax errors.

What they look for

Evaluation

• Basic understanding of system design concepts.
• Ability to break down a problem into components.
• Consideration of trade-offs.
• Communication of design ideas.

Sample questions

• Design a simple URL shortening service.

  System DesignAPIDatabase

• How would you design a basic rate limiter?

  System DesignAlgorithm

• Design the data model for a simple blog.

  System DesignDatabase

Prep for this round

1. 01Understand basic system design concepts: APIs, databases (SQL vs NoSQL), caching, load balancing (at a high level).
2. 02Practice designing simple systems like a URL shortener, a basic social media feed, or a rate limiter.
3. 03Focus on identifying core components and their interactions.
4. 04Be prepared to discuss trade-offs (e.g., consistency vs. availability, SQL vs. NoSQL).
5. 05Think about potential bottlenecks and how to address them simply.

Common rejection reasons

• ×Lack of understanding of basic system design principles.
• ×Inability to discuss trade-offs of different design choices.
• ×Poor communication of design ideas.
• ×Not considering scalability or reliability at a basic level.

What they look for

Evaluation

• Teamwork and collaboration potential.
• Attitude and motivation.
• Alignment with Ozon's values.
• Career aspirations and growth mindset.
• Problem-solving approach in a team context.

Sample questions

• Tell me about a time you had a conflict with a teammate and how you resolved it.

  BehavioralTeamworkConflict Resolution

• Describe a challenging technical problem you faced and how you overcame it.

  BehavioralProblem SolvingTechnical

• How do you prioritize your work when you have multiple tasks?

  BehavioralTime Management

• What kind of work environment do you thrive in?

  BehavioralCulture Fit

• Where do you see yourself in 5 years?

  BehavioralCareer Goals

Prep for this round

1. 01Prepare specific examples using the STAR method for behavioral questions (teamwork, conflict resolution, learning from mistakes, handling challenges).
2. 02Think about your career goals and how this role fits into them.
3. 03Be ready to discuss your preferred working style and what you look for in a team.
4. 04Show genuine interest in the team's work and Ozon's mission.
5. 05Ask thoughtful questions about the team, projects, and growth opportunities.

Common rejection reasons

• ×Poor cultural fit.
• ×Lack of enthusiasm or motivation.
• ×Negative attitude towards past experiences.
• ×Inability to articulate career goals.
• ×Lack of curiosity or engagement.