# Software Engineer
**Role:** Software Engineer · **Level:** SWE II
**Company:** [Moloco](https://scaleengineer.com/companies/moloco)
**Difficulty:** Medium to Hard
**Salary:** US$130000 - US$180000
**Experience:** 2 - 5
**Timeline:** ~7 days
The Software Engineer II interview at Moloco is designed to assess a candidate's technical proficiency, problem-solving abilities, and cultural fit within the company. It typically involves multiple rounds, including technical assessments, system design, and behavioral interviews, to evaluate a candidate's suitability for contributing to Moloco's innovative projects.
Canonical: https://scaleengineer.com/interviews/moloco/swe-ii-software-engineer
---
## Overall evaluation

- Technical Skills
- Communication and Behavioral

## Questions asked

- Given an array of integers, find the contiguous subarray with the largest sum.
- Design a system to store and retrieve user profiles.
- How would you handle a sudden spike in traffic to your application?
- Describe a time you disagreed with a teammate. How did you resolve it?
- What are the differences between processes and threads?
- Explain the concept of RESTful APIs.
- How do you ensure the security of your applications?
- What are your strengths and weaknesses as a software engineer?
- Design a rate limiter for an API.
- Tell me about a project you are particularly proud of.

## Preparation tips

### lists

- Review fundamental data structures and algorithms.
- Practice coding problems on platforms like LeetCode, HackerRank, or AlgoExpert.
- Study system design concepts and common architectural patterns.
- Prepare to discuss your past projects and technical challenges in detail.
- Research Moloco's mission, values, and products.
- Practice behavioral questions using the STAR method (Situation, Task, Action, Result).

### studyPlan

- {"title":"Data Structures and Algorithms","longDescription":"Weeks 1-2: Focus on core data structures (arrays, linked lists, trees, graphs, hash maps) and algorithms (sorting, searching, dynamic programming, graph traversal). Practice implementing these in your preferred language. Aim for at least 5-10 problems per data structure/algorithm type.","shortDescription":"Weeks 1-2: Data Structures & Algorithms fundamentals. Practice 5-10 problems per topic."}
- {"title":"System Design","longDescription":"Weeks 3-4: Dive into system design principles. Study topics like scalability, availability, reliability, databases (SQL vs. NoSQL), caching, load balancing, message queues, and microservices. Review common system design interview questions and practice designing systems like Twitter feed, URL shortener, etc.","shortDescription":"Weeks 3-4: System Design principles. Study scalability, databases, caching, etc. Practice designing systems."}
- {"title":"Behavioral Preparation","longDescription":"Week 5: Prepare for behavioral questions. Reflect on your past experiences and identify examples that demonstrate leadership, teamwork, problem-solving, and handling conflict. Use the STAR method to structure your answers. Research Moloco's company culture and values.","shortDescription":"Week 5: Behavioral questions preparation. Use STAR method. Research Moloco's culture."}
- {"title":"Mock Interviews","longDescription":"Week 6: Mock interviews. Conduct mock interviews with peers or mentors to simulate the actual interview environment. Get feedback on your technical explanations, problem-solving approach, and communication.","shortDescription":"Week 6: Mock interviews for practice and feedback."}

## Location differences

- {"location":"USA","differences":{"tips":["Familiarize yourself with common distributed system design patterns.","Practice explaining your thought process clearly and concisely.","Be prepared to discuss your experience with large-scale systems.","Research Moloco's tech stack and recent projects."],"interviewFocus":["Deep understanding of distributed systems principles.","Ability to design scalable and reliable systems.","Proficiency in cloud technologies (AWS, GCP, Azure).","Strong coding skills in at least one major programming language (e.g., Python, Java, Go)."],"commonQuestions":["How would you design a URL shortener service?","Explain the CAP theorem and its implications.","Describe a challenging technical problem you solved and how you approached it.","What are the trade-offs between SQL and NoSQL databases?","How do you handle concurrency in your applications?"]}}
- {"location":"India","differences":{"tips":["Prepare examples that showcase your problem-solving approach.","Be ready to discuss trade-offs in system design decisions.","Highlight any experience with performance optimization.","Understand Moloco's business domain and its technical challenges."],"interviewFocus":["Strong analytical and problem-solving skills.","Experience with data-intensive applications.","Understanding of algorithms and data structures.","Ability to work effectively in a collaborative team environment."],"commonQuestions":["Design a system to handle real-time bidding for online advertising.","How would you optimize a database query for performance?","Discuss your experience with microservices architecture.","Explain the concept of eventual consistency.","What are the best practices for API design?"]}}

## Round 1: Technical Coding Round 1
**Type:** Data Structures and Algorithms Interview · **Difficulty:** Medium · **Duration:** 45 min
Coding problems focused on data structures and algorithms.
This round focuses on assessing your fundamental programming skills. You will be asked to solve one or two coding problems, typically involving data structures and algorithms. The interviewer will evaluate your ability to write clean, efficient, and correct code, as well as your approach to problem-solving and your ability to explain your logic.
**Interviewers look for:** Strong grasp of data structures and algorithms.; Ability to translate a problem into working code.; Clear communication of thought process.; Attention to detail in coding.
**Evaluation criteria:** Correctness of the solution; Efficiency of the solution (time and space complexity); Code quality and readability; Ability to explain the approach and trade-offs
**Common rejection reasons:** Inability to solve coding problems within the given time.; Poor understanding of fundamental data structures and algorithms.; Code that is not clean, efficient, or well-tested.; Difficulty explaining the thought process.
## Questions

- Reverse a linked list.
- Find the kth smallest element in a binary search tree.
- Implement a function to check if a string is a palindrome.

## Preparation tips

- Practice coding problems on platforms like LeetCode.
- Understand the time and space complexity of your solutions.
- Be prepared to write code on a whiteboard or shared editor.
- Think out loud and explain your approach before coding.

## Round 2: System Design Round
**Type:** System Design Interview · **Difficulty:** Hard · **Duration:** 60 min
Design a scalable system based on a given problem statement.
This round evaluates your ability to design scalable, reliable, and maintainable software systems. You will be presented with a high-level problem (e.g., design a social media feed, a URL shortener, or a distributed cache) and asked to propose a system architecture. The focus is on your understanding of distributed systems, databases, caching, load balancing, and other relevant technologies.
**Interviewers look for:** Ability to design complex systems from scratch.; Understanding of distributed systems concepts.; Knowledge of various architectural patterns.; Ability to discuss trade-offs and make informed decisions.
**Evaluation criteria:** Scalability of the proposed design; Reliability and fault tolerance; Choice of technologies and justification; Handling of edge cases and constraints; Clarity and structure of the design
**Common rejection reasons:** Lack of understanding of system design principles.; Inability to design a scalable and reliable system.; Poor consideration of trade-offs and edge cases.; Difficulty in communicating design choices.
## Questions

- Design a system like Twitter's news feed.
- Design a URL shortening service.
- Design a distributed key-value store.

## Preparation tips

- Study common system design patterns and architectures.
- Practice designing systems for scale.
- Understand the trade-offs between different technologies.
- Be prepared to draw diagrams and explain your design choices.

## Round 3: Behavioral Round
**Type:** Behavioral and Managerial Interview · **Difficulty:** Medium · **Duration:** 45 min
Behavioral questions to assess cultural fit and past experiences.
This round focuses on your behavioral and cultural fit. The interviewer will ask questions about your past experiences, how you handle challenges, work in teams, and your motivations. The goal is to understand how you operate, your strengths and weaknesses, and whether you align with Moloco's values and work environment.
**Interviewers look for:** Cultural fit with Moloco.; Ability to work effectively in a team.; Past experiences that demonstrate key competencies.; Motivation and passion for software engineering.
**Evaluation criteria:** Teamwork and collaboration skills; Problem-solving approach in past experiences; Adaptability and learning agility; Alignment with Moloco's culture and values; Motivation and career goals
**Common rejection reasons:** Lack of alignment with company values.; Poor communication or interpersonal skills.; Inability to provide specific examples for behavioral questions.; Lack of enthusiasm or interest in the role/company.
## Questions

- Tell me about a time you faced a significant technical challenge and how you overcame it.
- Describe a situation where you had to work with a difficult colleague. How did you handle it?
- Why are you interested in Moloco and this specific role?

## Preparation tips

- Prepare specific examples using the STAR method.
- Research Moloco's company culture and values.
- Be honest and authentic in your responses.
- Ask thoughtful questions about the team and company.

## Round 4: Technical Round 2 / Deep Dive
**Type:** Technical Interview / Deep Dive · **Difficulty:** Medium to Hard · **Duration:** 45 min
Further technical assessment or deep dive into specific areas.
This round often serves as a final technical assessment or a deeper dive into specific areas based on previous rounds. It might involve more complex coding challenges, in-depth discussions about past projects, or further exploration of system design concepts. The goal is to confirm the candidate's technical capabilities and suitability for the SWE II level.
**Interviewers look for:** Strong technical foundation.; Ability to handle complex problems independently.; Good understanding of software development lifecycle.; Alignment with Moloco's engineering culture.
**Evaluation criteria:** Overall technical proficiency; Problem-solving approach; System design capabilities; Communication and collaboration; Potential for growth within the company
**Common rejection reasons:** Inability to solve complex coding problems.; Lack of depth in technical knowledge.; Poor performance in system design.; Not meeting the bar for SWE II level.
## Questions

- Discuss the trade-offs between different database indexing strategies.
- How would you design a distributed caching system?
- Explain the concept of idempotency in API design.

## Preparation tips

- Be prepared to discuss your resume in detail.
- Review concepts from previous rounds.
- Think critically about your past projects and contributions.
- Showcase your passion for technology and problem-solving.