Scale Engineer

Software Engineer

Software EngineerL4Medium to Hard

This interview process is for a Software Engineer (L4) position at LINE. It is designed to assess a candidate's technical skills, problem-solving abilities, and cultural fit within the company.

Rounds·3

Timeline·~14d

Experience·3 - 7 yrs

Comp band·US$110000 - US$150000

Interview time·150 min

Evaluation

What they measure.

  • Technical proficiency in core computer science concepts.
  • Ability to design scalable and robust systems.
  • Problem-solving skills and logical thinking.
  • Communication skills and ability to articulate technical ideas.
  • Teamwork and collaboration potential.
  • Cultural fit and alignment with LINE's values.

Preparation

How to prepare.

Tips

  1. Review fundamental computer science concepts (data structures, algorithms, operating systems, databases).
  2. Practice coding problems on platforms like LeetCode, HackerRank, or AlgoExpert, focusing on medium to hard difficulty.
  3. Study system design principles and common design patterns. Read books like 'Designing Data-Intensive Applications'.
  4. Prepare to discuss your past projects in detail, highlighting your contributions, challenges, and learnings.
  5. Understand LINE's products and services, and think about potential technical challenges and solutions.
  6. Practice behavioral questions using the STAR method (Situation, Task, Action, Result).
  7. Prepare thoughtful questions to ask the interviewer about the role, team, and company culture.

Study plan

Fig · Study plan — 04 phases

01 / 04
01

Phase 01 of 04

Data Structures and Algorithms

Weeks 1-2: Data Structures & Algorithms (Arrays, Lists, Trees, Graphs, DP, Greedy). Practice 5-10 problems/day.

Weeks 1-2: Focus on Data Structures and Algorithms. Cover arrays, linked lists, trees, graphs, hash tables, heaps, sorting, searching, dynamic programming, and greedy algorithms. Practice implementing these and analyzing their time and space complexity. Aim for 5-10 problems per day.

Questions

Commonly asked.

  • Tell me about yourself.
  • Why are you interested in LINE?
  • Describe a challenging project you worked on.
  • How do you handle tight deadlines?
  • What are your strengths and weaknesses?
  • Design a system for [specific LINE feature, e.g., LINE Today feed].
  • Given an array of integers, find the contiguous subarray with the largest sum.
  • How would you optimize a slow database query?
  • Describe your experience with cloud platforms (AWS, GCP, Azure).
  • How do you stay updated with new technologies?
  • Tell me about a time you disagreed with a teammate or manager.
  • What are your career goals?

Locations

Regional differences.

Fig · Regions — 02 locations

01 / 02

Location

Global (General)

Interview focus

System Design for large-scale applicationsDeep understanding of data structures and algorithmsProblem-solving and analytical thinkingExperience with distributed systemsProficiency in at least one major programming language (e.g., Java, Python, Go)

Common questions

  • How would you design a real-time notification system for LINE messenger?
  • Describe a challenging technical problem you faced and how you solved it.
  • How do you ensure code quality and maintainability in a large project?
  • What are your thoughts on microservices vs. monolithic architecture for a platform like LINE?
  • How do you handle concurrency issues in your code?
  • Tell me about a time you had to work with a difficult team member.

Tips

  • Familiarize yourself with LINE's products and services.
  • Be prepared to discuss your past projects in detail, focusing on your contributions and the impact.
  • Practice explaining complex technical concepts clearly and concisely.
  • Research common interview questions for Software Engineers at major tech companies.
  • Prepare questions to ask the interviewer about the team, projects, and company culture.

Rounds

Round-by-round.

Expand a step for evaluation criteria, sample questions, and prep notes.

Med

Technical Interview (Coding) · 45 min · Software Engineer / Senior Software Engineer

This round focuses on your fundamental programming skills. You will be asked to solve 1-2 coding problems, typically involving data structures and algorithms. The interviewer will assess your ability to write clean, efficient, and correct code, as well as your problem-solving approach and communication skills. Be prepared to discuss time and space complexity.

What they look for

Strong grasp of data structures and algorithms.Ability to translate a problem into code.Logical thinking and systematic approach to problem-solving.Clear communication of thought process.

Evaluation

  • Correctness of the solution.
  • Efficiency of the algorithm (time and space complexity).
  • Code clarity and style.
  • Ability to explain the approach and trade-offs.

Sample questions

  • Given a binary tree, find its inorder traversal.

    Data StructuresTreesRecursion

  • Implement a function to find the k-th smallest element in an unsorted array.

    AlgorithmsSortingQuickSelect

  • Find the length of the longest substring without repeating characters.

    AlgorithmsSliding WindowHash Maps

Prep for this round

  1. 01Practice coding problems on platforms like LeetCode, focusing on common patterns.
  2. 02Understand the time and space complexity of your solutions.
  3. 03Practice explaining your thought process out loud.
  4. 04Be ready to write code on a whiteboard or shared editor.

Common rejection reasons

  • ×Inability to articulate thought process.
  • ×Poor understanding of fundamental algorithms.
  • ×Inefficient or incorrect code.
  • ×Lack of problem-solving approach.

DSA

Coding questions at LINE.

Frequently reported on LINE loops

View all at LINE

Other guides

More at LINE.