Scale Engineer

SDE II

Software EngineerP6Medium to Hard

This interview process is for a Software Engineer (SDE II, P6 level) at Alibaba. It assesses technical proficiency, problem-solving skills, system design capabilities, and cultural fit.

Rounds·3

Timeline·~14d

Experience·4 - 8 yrs

Comp band·US$120000 - US$180000

Interview time·150 min

Evaluation

What they measure.

  • Problem-solving ability
  • Algorithmic thinking
  • Data structures knowledge
  • Code quality and efficiency

Preparation

How to prepare.

Tips

  1. Review fundamental data structures and algorithms (arrays, linked lists, trees, graphs, hash maps, heaps).
  2. Practice coding problems on platforms like LeetCode, HackerRank, or AlgoExpert, focusing on medium to hard difficulty.
  3. Study system design concepts: load balancing, caching, databases (SQL/NoSQL), message queues, microservices, CAP theorem.
  4. Prepare for behavioral questions using the STAR method (Situation, Task, Action, Result).
  5. Research Alibaba's products, services, and company culture.
  6. Understand common distributed systems challenges and solutions.
  7. Practice explaining your thought process clearly and concisely.
  8. Prepare questions to ask the interviewer.

Study plan

Fig · Study plan — 05 phases

01 / 05
01

Phase 01 of 05

Data Structures and Algorithms Fundamentals

Weeks 1-2: Data Structures & Basic Algorithms. Practice 5-7 problems/day. Big O.

Weeks 1-2: Focus on core data structures (arrays, linked lists, stacks, queues, hash tables) and basic algorithms (sorting, searching, recursion). Practice 5-7 problems per day. Understand time and space complexity (Big O notation).

Questions

Commonly asked.

  • Given an array of integers, find the contiguous subarray with the largest sum.
  • Design a system to store and retrieve user profiles for a social media platform.
  • Explain the difference between a process and a thread.
  • Describe a situation where you had to disagree with a team member. How did you handle it?
  • How would you optimize a slow database query?
  • Implement a function to reverse a linked list.
  • Discuss the trade-offs of using a message queue in a distributed system.
  • Tell me about a time you failed. What did you learn from it?
  • Design a rate limiter for an API.
  • What are the principles of object-oriented programming?

Locations

Regional differences.

Fig · Regions — 02 locations

01 / 02

Location

China (Hangzhou, Beijing, Shanghai)

Interview focus

Emphasis on practical experience with large-scale systems.Strong focus on distributed systems and cloud technologies (e.g., Alibaba Cloud).Behavioral questions often probe leadership potential and cross-functional collaboration.

Common questions

  • How would you design a distributed caching system for a large e-commerce platform?
  • Discuss a time you had to deal with a production issue under pressure. What was your approach?
  • Explain the trade-offs between SQL and NoSQL databases for a specific use case.
  • How do you ensure code quality and maintainability in a large team?

Tips

  • Familiarize yourself with Alibaba Cloud services if applying for a role in China.
  • Be prepared to discuss your contributions to open-source projects.
  • Highlight experience with agile methodologies and CI/CD pipelines.
  • Understand Alibaba's business model and how your role contributes to it.

Rounds

Round-by-round.

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

Med

Technical Interview (Coding) · 45 min · Software Engineer (Peer)

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 approach to problem-solving and debugging.

What they look for

Strong understanding of data structures and algorithms.Ability to translate a problem into a working code solution.Clear communication of thought process.Attention to edge cases and constraints.

Evaluation

  • Correctness of the solution
  • Efficiency of the solution (time and space complexity)
  • Code clarity and organization
  • Problem-solving approach

Sample questions

  • Given a binary tree, find its inorder traversal.

    TreeRecursionIteration

  • Find the kth smallest element in a sorted matrix.

    MatrixBinary SearchHeap

  • Implement a function to check if a string is a palindrome.

    StringTwo Pointers

Prep for this round

  1. 01Practice coding problems on platforms like LeetCode.
  2. 02Focus on understanding the underlying data structures and algorithms.
  3. 03Write code on a whiteboard or in a shared editor, simulating the interview environment.
  4. 04Practice explaining your thought process as you code.

Common rejection reasons

  • ×Inability to articulate thought process clearly.
  • ×Suboptimal or incorrect algorithmic solutions.
  • ×Poorly written or inefficient code.
  • ×Lack of understanding of basic data structures.

DSA

Coding questions at Alibaba.

Frequently reported on Alibaba loops

View all at Alibaba

Other guides

More at Alibaba.