BATJ and ByteDance's internal Java job interview analysis of these big companies, the difficulty of the interview is beyond your imagination

Many programmers are worried about the 35-year-old career crisis, and the data also shows that programmers over 40 years old hardly exist, most of them have been transferred to management positions, and the rest can only be forced to quit or change careers. However, staying in the comfort zone for too long may make it difficult for even small companies to pass the interview.

Programmers are the profession that needs to implement lifelong learning to the end. Once you stop learning, you will not be far from being eliminated. Programmers are very busy at work, so it's best to look at the interview questions from big companies in your free time . The effects of these interview questions may exceed your imagination :

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• Learn the interview methods and experience of seniors
• Test your own technical ability and cultivate your own sense of professional crisis
• Learn more techniques and exercise your sensitivity to technique
• Understand the important and difficult points of interviews with big factories, and provide corresponding experience for your own work
• Understand market conditions, pay attention to mainstream technologies, and think about the effect on your own technology stack

Redis interview topics

Most programmers who write business, when using Redis in actual development, only use Set Value and Get Value, and lack an overall understanding of Redis. Here is a summary of Redis common problems in the form of interview questions to solve everyone's knowledge blind spots.

1. What is Redis? Briefly describe its advantages and disadvantages?
2. Why use redis / why use cache
3. Why use redis instead of map/guava for caching?
4. The difference between redis and memcached
5. Talk about redis common data structure and usage scenario analysis
6. How does redis set the expiration time
7. Explain the redis memory elimination mechanism (there are 2000w data in MySQL, and only 20w data in Redis, how to ensure that the data in Redis are all hot data?)
8. How to deal with cache penetration and cache avalanche issues
9. Talk about redis transactions
10. Redis common exceptions and solutions
11. Talk about common application scenarios in a distributed environment
12. Talk about Redis cluster mode
13. How to solve Redis's concurrent competition Key problem
14. How to ensure data consistency between the cache and the database when it is double-written?
15. Talk about the redis persistence mechanism (how to ensure that the data can be restored after redis is hung up and restarted)
16. Why is single-threaded Redis so fast

 

 

Database interview topics

With the accumulation of work experience, I increasingly feel that for a programmer, having a good database design ability is very important, even the most important. Here is a summary of common database problems in the form of interview questions to solve everyone's knowledge blind spots.

1. Please briefly describe the names of the four transaction isolation levels supported by InnoDB in MySQL and the differences between each level?
2. What is the usage of ENUM in MySQL?
3. What are the method commands for MySQL database server performance analysis?
4. What storage engine is used in MySQL?
5. Tell me in detail about the four major characteristics of transactions (ACID) atomicity, consistency, isolation, and durability?
6. What is the concurrency of transactions? Transaction isolation level, what problems each level will cause, which level is MySQL default?
7. What is the difference between the three common MySQL storage engines (InnoDB, MyISAM, MEMORY)?
8. How to choose MySQL storage engine MyISAM and InnoDB
9. The difference between MySQL B+Tree index and Hash index?
10. What is a temporary table and when will the temporary table be deleted?
11. What is the difference between MySQL B+Tree index and Hash index?
12. The sql query statement determines which type of index to create and how to optimize the query
13. What are the locks (optimistic locks, pessimistic locks), and how to add exclusive locks when selecting?
14. What kind of fields are suitable for indexing
15. Are MySQL's MyISAM and InnoDB storage engines, transaction and lock levels, and their respective applicable scenarios?

 

 

Multithreading/High Concurrency Interview Topics

For concurrency and multithreading, it is a difficult problem that an excellent technical engineer must overcome in the process of growing up. It runs through the daily work and is also the focus of the focus of the induction interview. Here is a summary of the common problems of multi-threading in the form of interview questions to solve everyone's knowledge blind spots.

1. Why are the stop() and suspend() methods deprecated?
2. What is the difference between sleep() and wait()?
3. What are the similarities and differences between synchronous and asynchronous, and when should they be used?
4. When a thread enters a synchronized method of an object, can other threads enter other methods of this object
   ?
5. Briefly describe the similarities and differences between synchronized and java.util.concurrent.locks.Lock?
6. What is ThreadLocal?
7. The difference between run() and start().
8. Please tell me the thread synchronization method you know.
9. Thread scheduling and thread control.
10. What is a thread starving to death, and what is a livelock?
11. What is the busy loop in multithreading?
12. What is a volatile variable? What is the difference between volatile variables and atomic variables?
13. What guarantee does volatile type variables provide? Can a non-atomic operation become an atomic operation?
14. Ordinary thread and daemon thread?
15. Thread starvation and livelock?

 

 

Performance optimization topic

From basic code, to JVM in-depth tuning, design pattern optimization, database tuning, concurrent programming performance optimization, Tomcat tuning, MySQL performance optimization, let all illusions be self-defeating!

JVM related interview questions

1. What is JVM?
2. How does the class loader load the class file?
3. Parent Delegation Model (Parent Delegation Model)?
4. What are the garbage collection algorithms?
5. When does GC start?
6. Which areas are the JVM memory divided into, and what is the function of each area?

Tomcat interview topics

1. How to optimize Tomcat?
2. Memory tuning
3. Garbage collection strategy tuning
4. Shared session processing
5. About the number of Tomcat sessions
6. Monitor Tomcat's memory usage
7. Tomcat working mode?

SQL optimization interview topics

1. Database read-write separation, master-slave replication, master-slave replication analysis?
2. How to solve MySQL slow query?
3. Use explain to optimize sql and index?
4. Transaction recovery mechanism (REDO log and UNDO log) when the database crashes?
5. MySQL high concurrency environment solution?

 

 

Distributed interview questions

Distributed is divided into distributed cache (Redis), distributed lock (Redis or Zookeeper), distributed service (Dubbo or SpringCloud), distributed service coordination (Zookeeper), distributed message queue (Kafka, RabbitMq), distributed Session , Distributed transactions, distributed search (elastaticSearch), etc.; here is a summary of distributed common problems in the form of interview questions to solve everyone's knowledge blind spots.

1. What are the theories of distributed?
2. How do you understand distributed consistency?
3. How do you understand distributed transactions? What are the protocols for distributed transactions?
4. What are the solutions for distributed transactions?
5. How to ensure the idempotence of distributed systems?
6. How does Redis implement distributed locks?
7. Redis adopts a multi-master and multi-slave cluster mode. Is the data of each master node consistent?
8. What is a cache avalanche? How to solve the cache avalanche?
9. What is cache penetration? How to solve cache penetration?
10. What is the principle of Zookeeper?
11. What are the application scenarios of Zookeeper?
12. What are the types of Zookeeper nodes? What's the difference?
13. Why can Zookeeper be a registration center?
14. How does Zookeeper implement distributed locks?
15. Talk about the read and write mechanism of Zookeeper. How does Zookeeper maintain consistency?

Distributed database interview series: Memcached+Redis+MongoDB

 

Distributed communication interview series: ActiveMQ+RabbitMQ+Kafka

 

Distributed current limiting interview series: Nginx+zookeeper

 

Microservice Architecture Interview Special Series: Dubbo+Spring Boot+Spring Cloud

 

At last

These materials are compiled and hoped to have some reference for Java development friends and avoid detours. The focus of this article is whether you have gained and grown, and the rest is not important. I hope readers can keep this in mind.

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