2024 Summer Internship Interview Experiences and Questions for Meituan, Baidu, and Perfect World (Backend Development)

The author, a recent intern, recounts applying to over twenty companies for a 2024 summer internship, ultimately securing positions at Meituan, Baidu, and Perfect World, and notes that resume screening has become stricter, with many candidates being filtered out before any written test.

Meituan Database R&D Internship (Backend Development)

First Round

Self‑introduction

Project introduction

Project deep‑dive (30 min)

How would you rate‑limit massive incoming requests?

What to do if a program crashes while writing to MQ?

Explain MySQL logs

Purpose of binlog

Experience with DTS

How to monitor service availability in the cloud?

Algorithm question: LeetCode 124.

Second Round

Algorithm implementation (self‑designed)

Project discussion

Scenario questions:

Standard questions:

Casual chat about strengths, weaknesses, graduate study performance, other offers, and recent reading.

Baidu Backend Interview (Video)

First Round

Self‑introduction

Project introduction

Project‑specific questions

What happens when a URL is entered in a browser?

Explain the four‑way handshake

What occurs after a TCP connection is established and the client goes offline?

Methods of the Object class

Experience with Java's built‑in thread pool

How would you implement a custom Map?

Understanding of the JVM memory model

How is the heap divided and why?

Use of Java thread pools

Algorithm: palindrome string

Second Round

Self‑introduction

Project introduction

Project questions

Algorithm: binary‑tree level order traversal

Algorithm discussion: issues with multithreaded tree traversal

Database knowledge overview

Write SQL statements

Third Round

Self‑introduction

Project introduction

Project questions

Describe a difficult project problem and its solution

Explain known I/O models and I/O multiplexing

Prove that the middle number of twin primes is divisible by 6

Deduplicate 4 GB of phone numbers (8‑bit each) with only 200 MB of memory

Perfect World Java R&D Internship (Backend Development)

Self‑introduction

Project introduction

Explain Dubbo request handling flow

Is load balancing performed on client or server side?

Basic Redis data types and suitable scenarios

When can Redis usage degrade performance?

Introduce Spring framework

Detail AOP implementation and dynamic proxy types

Interceptor methods vs filter methods comparison

Other middleware experience (e.g., MyBatis‑Plus)

Problems solved by MQ

Spring Boot auto‑configuration overview

How does Spring Boot discover JARs for auto‑configuration?

MySQL index concepts

Java thread pool parameters

Thread creation policy when core pool size is 5 and 5 tasks arrive

HashMap put operation process

Is HashMap thread‑safe? Which map implementation is?

Methods to override for a Map key

Purpose of a service registry

SQL: add gender column to a user table and count users by gender

SQL: retrieve gender groups with count greater than 2