Gold three silver four finally entered Alipay, Java interview sharing

Preface

Every programmer has the dream of a big factory, and the Internet big factory is naturally the most popular in Alibaba . Today I will share the experience of a guy entering Alibaba (three sides of Alipay)!

This year, due to the epidemic, the entire Internet industry is relatively severe. I was lucky. I accidentally received an interview with Alipay not long ago (three sides) and got an offer.

Originally after the Spring Festival, it was the peak season for job hunting. Most people were ready to get a job they wanted in two months. However, this year’s 2020 is a bit special, with pneumonia raging, yes. Our work and life have had a great impact. So, is it true that we don’t work or study? In fact, it is precisely because the virus is spreading now that it is better for us to stay at home and study hard. For Java programmers, use these two or three months to study hard, start preparing, and wait for the epidemic to improve and start interviews without being timid.

I also kept reviewing during this time, and I was lucky enough to get the offer of Alipay!

Alipay side

1. Introduce yourself.
2. What are the core designs involved in the project
3. ArrayList and LinkedList bottom layer
4. HashMap and thread-safe ConcurrentHashMap, and their advantages and disadvantages
5. How to achieve thread safety in Java
6. Which is better, Synchronized or Lock?
7. How is the get() method in HashMap implemented?
8. What scenarios can HashMap be used in?
9. JVM, garbage collection mechanism, memory division, etc.
10. SQL optimization, commonly used indexes?
11. What more questions need to be asked.

Alipay two sides

1. Without self-introduction, I just asked which Java development-related projects I have done.
2. Which technologies are you familiar with?
3. Multi-threaded state diagram, how does the state flow?
4. Deadlock, the cause of the deadlock
5. Page lock, optimistic lock, pessimistic lock?
6. How does optimistic locking ensure thread safety?
7. Have you used the thread pool, the corresponding benefits, how to use it?
8. Two 10G files contain some URLs and the memory is only 1G. How to merge these two files to find the same URL?
9. More than 1000 concurrent threads, 10 machines, each machine has 4 cores, and the thread pool size is designed.
10. Code question: Two ordered arrays, there are duplicate numbers in the array, merge them into an ordered array, and remove the duplicate numbers.
11. Talk about your strengths.

Alipay three sides

1. What has been done in jvm performance tuning
2. How to do database performance tuning
3. Principles of distributed systems: CAP, eventual consistency, idempotent operations, etc.
4. Under high concurrency, how does our system support a large number of requests?
5. How the cluster synchronizes session state
6. Commonly used NOSQL, have you made a comparison?
7. Under what circumstances will an avalanche occur, and how to deal with it?
8. Principles of load balancing
9. Database transaction attributes
10. When communicating with colleagues, how to resolve conflicts?
11. What do you feel lacking in your work?
12. Do you have any questions?
13. Expect salary?
14. Why leave the current company?

Interview Collection

I have also compiled the following interview documents for a long time. It is very suitable to review the interview questions. Those who need to get it can directly add the assistant's WeChat: vip1024x  can get it for free

java core document

Java part : Java basics, collections, concurrency, multithreading, JVM, design patterns

Data structure algorithm: Java algorithm, data structure

Open source framework: Spring, MyBatis, MVC, netty, tomcat

Distributed part: architecture design, Redis cache, Zookeeper, kafka, RabbitMQ, load balancing, etc.

Microservice part: SpringBoot, SpringCloud, Dubbo, Docker

Actual Combat Series: Spring Family Bucket Actual Combat Document

Spring Cloud microservices in action

brief introduction:

Starting from the popular concept of microservice architecture, this book introduces in detail SpringCloud's solutions and basic components for several core elements in the microservice architecture. For the introduction of each component, this book mainly combines examples and source code to help readers better understand the usage and operating principles of these components. At the same time, in the process of introduction, it also contains some problems and solutions that the author encountered in practice, which can be used as a reference for readers in practice.

This book is suitable for all Java developers, especially for those who are doing microservice architecture technology selection or are implementing microservice architecture team review and reference.

 

Spring microservices in action

This book is written for working JavalSpring developers who need practical advice and examples of how to build and implement microservice-based applications. When writing this book, I hope it will be based on the core microservice patterns combined with Spring Boot and Spring Cloud examples, which demonstrate these patterns. Therefore, readers will find that almost every chapter discusses specific microservice design patterns, as well as examples of patterns implemented using Spring Boot and Spring Cloud.

 

In-depth practice of Spring Boot 2.x

to sum up

For the interview with a big factory, I want to emphasize that the mentality is really important, and it is the key to determining your performance in the interview process. If you can’t perform normally, it’s likely that you missed the offer because of a small mistake, so you must pay attention to it. stand up. Another reminder, full review is the key to eliminating your nervous state of mind, but if you review enough, you will naturally have more confidence in the interview process.

All the learning materials in the above content can be provided for free, I hope you can get your favorite offer!

How to get

I have also compiled the above interview documents for a long time. It is very suitable to review the interview questions . Those who need to get it can directly add the assistant's WeChat: vip1024x  can get it for free