# Software Engineer
**Role:** Software Engineer · **Level:** SDE III
**Company:** [InMobi](https://scaleengineer.com/companies/inmobi)
**Difficulty:** Hard
**Salary:** US$140000 - US$180000
**Experience:** 5 - 10
**Timeline:** ~7 days
This interview process is designed to assess candidates for the Software Engineer III role at InMobi. It evaluates technical proficiency, problem-solving skills, system design capabilities, and cultural fit.
Canonical: https://scaleengineer.com/interviews/inmobi/sde-iii-software-engineer
---
## Overall evaluation

- Technical Skills
- System Design
- Behavioral and Leadership
- Cultural Fit

## Questions asked

- Design a system to handle real-time analytics for a mobile application.
- How would you optimize a database query that is causing performance issues?
- Describe a time you had to deal with a production outage. What steps did you take?
- What are the trade-offs between using a monolithic architecture versus a microservices architecture?
- How do you ensure the quality and reliability of the code you write?
- Tell me about a time you disagreed with a technical decision made by your team lead.
- How would you design a distributed cache system?
- Explain the concept of eventual consistency.
- What are your thoughts on test-driven development (TDD)?
- How do you approach mentoring junior engineers?

## Preparation tips

### lists

- Review fundamental computer science concepts (data structures, algorithms, operating systems, databases).
- Practice coding problems on platforms like LeetCode, HackerRank, focusing on medium to hard difficulty.
- Study system design principles and common architectural patterns.
- Prepare for behavioral questions by reflecting on past experiences using the STAR method.
- Research InMobi's products, services, and recent news.
- Understand the challenges and opportunities in the mobile advertising industry.

### studyPlan

- {"title":"Data Structures and Algorithms","longDescription":"Weeks 1-2: Focus on core data structures (Arrays, Linked Lists, Trees, Graphs, Hash Tables) and algorithms (Sorting, Searching, Dynamic Programming, Greedy Algorithms). Practice implementing these efficiently and analyze their time/space complexity.","shortDescription":"Weeks 1-2: Data Structures & Algorithms fundamentals."}
- {"title":"System Design","longDescription":"Weeks 3-4: Dive into system design concepts. Cover topics like scalability, availability, consistency, load balancing, caching, databases (SQL vs NoSQL), message queues, and microservices. Practice designing common systems like Twitter feed, URL shortener, etc.","shortDescription":"Weeks 3-4: System Design principles and practice."}
- {"title":"Behavioral Preparation","longDescription":"Week 5: Prepare for behavioral questions. Reflect on your career experiences, focusing on leadership, teamwork, conflict resolution, and problem-solving. Use the STAR method (Situation, Task, Action, Result) to structure your answers.","shortDescription":"Week 5: Behavioral preparation using STAR method."}
- {"title":"Company Research","longDescription":"Week 6: Research InMobi thoroughly. Understand their business model, products, target audience, and recent developments. Prepare questions to ask the interviewer that demonstrate your interest and understanding.","shortDescription":"Week 6: Company research and question preparation."}
- {"title":"Final Preparation","longDescription":"Week 7: Mock interviews and final review. Practice coding and system design problems under timed conditions. Review your notes and ensure you are confident in your understanding of key concepts.","shortDescription":"Week 7: Mock interviews and final review."}

## Location differences

- {"location":"Bangalore","differences":{"tips":["Highlight instances where you influenced technical direction.","Be prepared to discuss your contributions to open-source projects or technical communities.","Research InMobi's recent technological advancements and challenges."],"interviewFocus":["Emphasis on leadership and mentorship experience.","Deeper dive into architectural decisions and trade-offs.","Understanding of scalability challenges in a high-traffic environment."],"commonQuestions":["Discuss a challenging project you led.","How do you handle technical disagreements within a team?","Describe a time you had to mentor junior engineers.","What are your thoughts on the current tech stack at InMobi?","How do you stay updated with new technologies relevant to mobile advertising?"]}}
- {"location":"Gurugram","differences":{"tips":["Practice designing scalable systems, considering factors like latency, throughput, and fault tolerance.","Be ready to articulate your design choices and justify them with trade-offs.","Familiarize yourself with common distributed system patterns and technologies."],"interviewFocus":["Strong focus on distributed systems and scalability.","In-depth analysis of system design and architecture.","Problem-solving under pressure and handling ambiguity."],"commonQuestions":["How would you design a real-time bidding system?","Explain the trade-offs between different caching strategies.","Describe a situation where you had to optimize performance for a large-scale system.","What are the key considerations for building a distributed system?","How do you approach debugging complex production issues?"]}}

## Round 1: Coding Proficiency
**Type:** Technical Interview - Coding · **Difficulty:** Hard · **Duration:** 60 min
Assess core programming skills with coding challenges.
This round focuses on your core programming skills. You will be asked to solve 1-2 coding problems that require a good understanding of data structures and algorithms. The interviewer will assess your ability to analyze the problem, devise an efficient solution, and implement it correctly in a chosen programming language. Expect questions that test your knowledge of arrays, strings, linked lists, trees, graphs, hash maps, sorting, searching, and dynamic programming.
**Interviewers look for:** Strong analytical and problem-solving skills.; Proficiency in at least one programming language.; Ability to write clean, efficient, and well-structured code.; Understanding of time and space complexity.
**Evaluation criteria:** Problem-solving approach; Correctness of the solution; Efficiency of the solution (time and space complexity); Code clarity and maintainability; Ability to handle edge cases
**Common rejection reasons:** Inability to articulate thought process clearly.; Lack of fundamental data structures and algorithms knowledge.; Poor coding practices (e.g., inefficient solutions, unreadable code).
## Questions

- Given a binary tree, find the lowest common ancestor of two given nodes in the tree.
- Implement a function to find the k-th largest element in an unsorted array.
- Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.

## Preparation tips

- Practice coding problems on platforms like LeetCode, HackerRank, focusing on medium to hard difficulty.
- Understand the time and space complexity of your solutions.
- Be prepared to explain your thought process step-by-step.
- Practice writing code on a whiteboard or a shared editor without relying on IDE features.

## Round 2: System Design and Architecture
**Type:** System Design Interview · **Difficulty:** Hard · **Duration:** 60 min
Assess ability to design scalable and distributed systems.
This round evaluates your ability to design large-scale, distributed systems. You will be presented with a high-level problem statement (e.g., design a URL shortener, a social media feed, a real-time chat system) and expected to design a system that meets the requirements. The focus is on your understanding of scalability, availability, consistency, latency, and fault tolerance. You'll need to discuss various components, data models, APIs, and potential bottlenecks.
**Interviewers look for:** Ability to design complex, scalable, and reliable systems.; Understanding of distributed systems principles.; Knowledge of various architectural patterns and technologies.; Ability to articulate design decisions and justify trade-offs.
**Evaluation criteria:** System design approach; Scalability and performance considerations; Fault tolerance and reliability; Trade-off analysis; Clarity of explanation
**Common rejection reasons:** Inability to design scalable and robust systems.; Lack of understanding of distributed systems concepts.; Poor trade-off analysis and justification of design choices.
## Questions

- Design a system like Twitter's news feed.
- Design a rate limiter for an API.
- Design a distributed key-value store.

## Preparation tips

- Study common system design patterns and architectural styles.
- Practice designing various real-world systems.
- Understand the trade-offs between different technologies and approaches.
- Be prepared to draw diagrams and explain your design clearly.

## Round 3: Behavioral and Managerial Fit
**Type:** Behavioral and Managerial Interview · **Difficulty:** Medium · **Duration:** 45 min
Assess behavioral aspects, leadership, and cultural fit.
This round focuses on your behavioral aspects, leadership potential, and how you fit within the team and company culture. You'll be asked questions about your past experiences, focusing on situations where you demonstrated leadership, teamwork, conflict resolution, and problem-solving. The interviewer wants to understand your motivations, career goals, and how you handle challenges.
**Interviewers look for:** Effective communication and interpersonal skills.; Ability to work collaboratively in a team.; Demonstrated leadership qualities and mentorship experience.; Alignment with InMobi's values and culture.; Self-awareness and ability to learn from past experiences.
**Evaluation criteria:** Communication skills; Teamwork and collaboration; Leadership and mentorship; Problem-solving approach in past experiences; Cultural fit and alignment with company values
**Common rejection reasons:** Poor communication skills.; Lack of collaboration or teamwork.; Negative attitude or lack of enthusiasm.; Inability to provide specific examples for behavioral questions.
## Questions

- Tell me about a time you had to lead a project. What were the challenges and how did you overcome them?
- Describe a situation where you had a conflict with a colleague. How did you resolve it?
- How do you handle constructive criticism?
- What motivates you in a work environment?

## Preparation tips

- Prepare specific examples from your past experiences using the STAR method (Situation, Task, Action, Result).
- Reflect on your strengths and weaknesses, and how you've worked on them.
- Think about why you want to work at InMobi and for this specific role.
- Be ready to discuss your career aspirations and how this role aligns with them.