# Software Engineer
**Role:** Software Engineer · **Level:** SWE I
**Company:** [Moloco](https://scaleengineer.com/companies/moloco)
**Difficulty:** Medium
**Salary:** US$90000 - US$120000
**Experience:** 0 - 2
**Timeline:** ~7 days
This interview process is for a Software Engineer I role at Moloco, focusing on foundational software engineering principles, problem-solving abilities, and cultural fit.
Canonical: https://scaleengineer.com/interviews/moloco/swe-i-software-engineer
---
## Overall evaluation

- Technical Skills
- Behavioral and Cultural Fit

## Questions asked

- Write a function to reverse a linked list.
- Given an array of integers, find the two numbers that add up to a specific target.
- Explain the difference between a process and a thread.
- Describe a situation where you had to deal with a conflict in a team.
- How would you optimize a slow-running database query?
- What are your strengths and weaknesses as a software engineer?
- Tell me about a time you failed and what you learned from it.

## Preparation tips

### lists

- Brush up on fundamental data structures and algorithms.
- Practice coding problems on platforms like LeetCode or HackerRank.
- Review object-oriented programming (OOP) concepts.
- Understand basic system design principles.
- Prepare to discuss your resume and past projects in detail.
- Research Moloco's products, mission, and values.
- 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 like arrays, linked lists, stacks, queues, trees, and hash maps. Practice implementing them and understanding their time and space complexity. Cover fundamental algorithms such as sorting (bubble, merge, quick), searching (binary search), and graph traversal (BFS, DFS).","shortDescription":"Weeks 1-2: Data Structures & Algorithms fundamentals. Practice implementations and complexity analysis."}
- {"title":"Object-Oriented Programming","longDescription":"Week 3: Dive into object-oriented programming (OOP) principles (encapsulation, inheritance, polymorphism, abstraction). Review common design patterns and their applications. Practice coding problems that require OOP design.","shortDescription":"Week 3: Object-Oriented Programming (OOP) and Design Patterns. Practice OOP-based coding."}
- {"title":"System Design & Behavioral","longDescription":"Week 4: Begin exploring basic system design concepts. Understand scalability, availability, and reliability. Practice designing simple systems like a URL shortener or a basic social media feed. Also, prepare for behavioral questions by reflecting on past experiences and aligning them with Moloco's values.","shortDescription":"Week 4: Basic System Design and Behavioral Preparation. Practice system design and STAR method for behavioral questions."}

## Location differences

- {"location":"Palo Alto","differences":{"tips":["Highlight any open-source contributions or personal projects.","Be prepared to discuss your thought process for solving problems.","Emphasize your ability to work effectively in a team."],"interviewFocus":["Adaptability to new technologies and learning agility.","Problem-solving skills in a fast-paced environment.","Teamwork and collaboration."],"commonQuestions":["Tell me about a challenging project you worked on during your internship.","How do you approach debugging a complex issue?","Describe a time you had to learn a new technology quickly."]}}
- {"location":"Seoul","differences":{"tips":["Review common data structures (arrays, linked lists, trees, hash maps) and algorithms (sorting, searching).","Practice explaining your solutions clearly and concisely.","Be ready to write pseudocode or actual code on a whiteboard or shared editor."],"interviewFocus":["Core data structures and algorithms knowledge.","Understanding of fundamental computer science concepts.","Ability to translate requirements into code."],"commonQuestions":["Can you explain the concept of Big O notation?","Describe a data structure you've used and why.","How would you design a simple URL shortener?"]}}

## Round 1: Data Structures and Algorithms
**Type:** Technical Interview (Data Structures & Algorithms) · **Difficulty:** Medium · **Duration:** 45 min
Assess core coding and problem-solving skills with data structures and algorithms.
This round focuses on your core technical skills. You will be asked to solve coding problems, typically involving data structures and algorithms. The interviewer will assess your ability to understand the problem, devise a solution, write clean and efficient code, and explain your thought process. Expect questions that test your knowledge of arrays, strings, linked lists, trees, graphs, sorting, and searching.
**Interviewers look for:** A systematic approach to problem-solving.; Clean and efficient code.; Ability to explain their reasoning.; Understanding of time and space complexity.
**Evaluation criteria:** Problem-solving skills; Coding ability; Understanding of data structures and algorithms; Communication clarity
**Common rejection reasons:** Inability to articulate thought process.; Poor coding practices.; Fundamental misunderstanding of data structures/algorithms.; Lack of problem-solving approach.
## Questions

- Given a binary tree, determine if it is a valid binary search tree.
- Find the kth smallest element in a sorted matrix.

## Preparation tips

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

## Round 2: System Design
**Type:** System Design Interview · **Difficulty:** Medium · **Duration:** 45 min
Assess ability to design scalable and robust software systems.
This round evaluates your ability to design software systems. You'll be given a high-level problem (e.g., design a URL shortener, a Twitter feed, or a rate limiter) and asked to propose a solution. The focus is on your understanding of scalability, reliability, trade-offs, and how different components of a system interact. You'll need to discuss database choices, API design, caching strategies, and potential bottlenecks.
**Interviewers look for:** Ability to design scalable and reliable systems.; Understanding of trade-offs in design decisions.; Clear articulation of design choices.; Consideration of various system components (databases, APIs, caching).
**Evaluation criteria:** System design thinking; Scalability considerations; Trade-off analysis; Communication of design
**Common rejection reasons:** Lack of understanding of system design principles.; Inability to handle scale or trade-offs.; Poor communication of design choices.; Overly simplistic or overly complex solutions.
## Questions

- Design a URL shortening service like Bitly.
- Design a system to count the top K trending items on Twitter.

## Preparation tips

- Study common system design patterns and concepts.
- Practice designing various systems.
- Be prepared to discuss trade-offs for your design choices.
- Think about scalability, availability, and performance.

## Round 3: Behavioral and Cultural Fit
**Type:** Behavioral Interview · **Difficulty:** Easy · **Duration:** 30 min
Assess cultural fit, teamwork, and motivation.
This round focuses on your behavioral aspects and cultural fit. You'll be asked questions about your past experiences, how you handle challenges, your teamwork abilities, and your motivations for joining Moloco. The interviewer wants to understand if you align with the company's values and if you'll be a positive addition to the team. Use the STAR method to structure your answers.
**Interviewers look for:** Enthusiasm for Moloco's mission.; Ability to work well in a team.; Proactiveness and a growth mindset.; Honesty and self-awareness.
**Evaluation criteria:** Teamwork and collaboration skills; Motivation and passion for the role; Alignment with company values; Communication and interpersonal skills
**Common rejection reasons:** Poor cultural fit.; Lack of enthusiasm or motivation.; Inability to articulate past experiences effectively.; Negative attitude towards past employers or colleagues.
## Questions

- Tell me about a time you had to work with a difficult teammate.
- Why are you interested in Moloco?
- Describe a project you are particularly proud of and your role in it.

## Preparation tips

- Research Moloco's mission, values, and culture.
- Prepare examples using the STAR method for common behavioral questions.
- Be ready to discuss your career goals and why Moloco is a good fit.
- Show genuine enthusiasm for the role and the company.