Alibaba Java Interview Questions – First, Second, and Third Round Topics

This post shares the latest set of interview questions encountered in recent Alibaba three‑round interviews, which are reportedly common across many Alibaba group subsidiaries.

First round questions include:

Self‑introduction

How Java implements polymorphism

Various locks in Java

Database isolation levels, dirty reads, phantom reads, ACID, MySQL isolation levels

MySQL index implementation and how to solve slow queries

Implementation of database locks

Deadlock conditions, differences between processes and threads

TCP/IP model, differences between TCP and UDP

Linux commands for network, memory, and logs

Modules in Spring

Differences among HashMap, Hashtable, and ConcurrentHashMap

Underlying implementation of CAS

Java garbage collection

Stacks and queues

Deduplication of 100,000 URLs

TCP states, TCP vs UDP, TIME_WAIT

Second round questions include:

Use of the volatile keyword

JVM garbage‑collection algorithms

JVM memory model

Ways to start threads and types of thread pools

Spring IoC principles and how to implement a custom IoC container

Whether MongoDB uses row‑store or column‑store

Basics of HBase, Redis, and Nginx

MySQL indexing, differences between clustered and non‑clustered indexes

Third round questions include:

JVM tuning and troubleshooting a hung program

Implementing distributed locks with Redis

Experience with Dubbo, Zookeeper, and Netty

Project involvement: drawing a cluster deployment diagram, service relationships, and core design points

The article notes that Youzhi Academy will soon publish a comprehensive summary of Alibaba interview topics, including questions, resumes, and experience sharing, and invites readers to follow the official website for updates.

Additional resources mention a continuously updated list of essential Java questions and answers, and a call‑to‑action to reply with "bat" to receive more information.