preface
It comes from a summary of the four faces of Ali
I think it is quite normal to have the idea of finding an offer from a big factory, which is not our after-dinner talk but the pursuit of every technical person. Such as Ali, Tencent, Meituan, Bytedance, JINGdong and so on, the technical atmosphere and technical standards are obviously better than some entrepreneurial companies/small companies. If I can practice in such companies for several years, I believe my ability will be greatly improved. Both school and social recruitment can not avoid all kinds of interviews, written tests, how to prepare for these things is particularly important. There are rules for both written tests and interviews.
Because companies generally have a professional team responsible for the interview, some knowledge you have mastered or simply memorize, the interviewer ask you can see (PS: especially to interview you truly feel ready to interview time is not enough, you can choose some more interview often ask questions, pay attention to understanding, must not rote). Don’t put too much hope on various aspects, try to improve their overall ability.
The saying “80% of offers are in 20% of hands” is not without reason. It is true that your ability plays a large part in determining whether you can succeed in the interview, but if your mood or luck is bad, you still cannot get a satisfactory offer. Luck aside, take the mentality, do not be discouraged or doubt your ability because of the failure of the interview, after the failure of the interview to sum up the reasons for the failure, you will find that you will be more and more powerful.
Ali often asks in interviews what the skills are
Data structure, multithreading, JVM, Spring, optimization, messaging framework, distribution, caching, etc., as well as the framework you have used and the foundation of the first round is very important, after passing the likelihood of acceptance is relatively high!
One side (JVM, concurrency, locking, data structure, etc.)
- Introduce yourself (tell me what you are good at and what technology you are good at)
- What is the difference between Treemap and HashMap? What’s the difference between HashMap and ConcurrentHashMap?
- How is HashMap implemented underneath (JDK1.8 changes)?
- What’s a consistent algorithm for Hash?
- What GC algorithms and collection strategies do you know? What is the mechanism of GC?
- The rationale for garbage collector? Can memory be reclaimed immediately? How do you proactively inform the JVM to do garbage collection?
- Parental delegation model mechanism
- What are the core construction parameters for thread pool creation?
- Optimistic locks and pessimistic locks? Reentrant and Synchronized?
- Are they all reentrant locks? Which is more efficient?
- What are the differences between CountDownLaunch and Cylicbarrior and in which scenarios are they used?
- What is the difference between Http and Https and how does Https encrypt?
- Future career planning and ideas
Second side (database, protocol, Spring, etc.)
- Introduce yourself and talk about the projects you think you have done well!
- What are the four transaction isolation levels InnoDB supports? What’s the difference? What is the MySQL isolation level?
- What about the nature of transactions? Talk about the analysis of slow queries?
- What do you understand about BTree?
- What are some common optimization methods for MySQL?
- Http request process, DNS resolution process?
- Three handshakes and four handshakes?
- What’s the difference between a B+ tree index and a Hash index?
- How does Spring IOC manage dependencies between beans, and how does it avoid circular dependencies?
- Design patterns during SpringBean creation?
- How does AOP work?
- What is the basic architecture of Tomcat?
Three sides (mainly cache, high concurrency, distributed)
- Concurrency lessons learned in your own projects
- MySQL lock concurrency What is the mechanism of locking?
- How to prevent deadlocks and ensure data consistency in high concurrency scenarios?
- Clustering and load balancing algorithm and implementation?
- Talk about the design of sub-database and sub-table?
- What are the solutions to the distributed dilemma brought about by database and table division?
- How do the Redis and Setnx commands implement distributed locking? How do I queue asynchronously using Redis? What are the downsides?
- Cache breakdown concept and solution?
- Redis data structure? Thread model? Redis data elimination mechanism?
- Redis data consistency issues
- Implementation of MQ’s underlying principles?
- How to implement blocking queues without Java?
- How does load balancing work?
- How to realize peak clipping and current limiting in high concurrency environment?
Four sides (start with major projects)
Describe the middleware used in the project (
Dubbo/MQ/Zookeeper/Redis/Kafka)?
- What causes an avalanche? How can this be avoided?
- Design ideas for high concurrency architectures?
- What problems and solutions did you encounter in previous projects?
- What setbacks have you encountered in your life? What was the final solution?
summary
First-tier Internet companies pay more attention to the ability to solve problems in practical projects, while the other side of the pilot mainly focuses on THE JVM, multithreading, the underlying principles of basic knowledge, and the ability to deal with high concurrency. Here also do not pull what interview skills, relaxed play good, I wish you gold three silver four seasons can have a high salary satisfactory work!
Ali often asks how interview techniques are reviewed.
1, Hot interview questions and answers
Do enough work before the interview to improve your interview success rate. Here is a list of 350 popular Internet frequently asked interview questions and answers to help you get an offer
Interview treasure book + books + core knowledge acquisition: please forward it and add assistant Vx: Yunduoa2019 after paying attention to it or scan the qr code below and follow the guidance of the assistant to obtain it by yourself
2, multi-threading, high concurrency, cache entry to the actual project PDF books
Books, reading can learn and also conducive to calm mind!
Interview treasure book + books + core knowledge acquisition: please forward it and add assistant Vx: Yunduoa2019 after paying attention to it or scan the qr code below and follow the guidance of the assistant to obtain it by yourself
3. The article mentioned sorting out the answers to the interview questions
Interview treasure book + books + core knowledge acquisition: please forward it and add assistant Vx: Yunduoa2019 after paying attention to it or scan the qr code below and follow the guidance of the assistant to obtain it by yourself
4, Java core knowledge interview treasure book
It covers JVM, JAVA collection, JAVA multi-threaded concurrency, JAVA fundamentals, Spring Principles, microservices, Netty and RPC, networks, logs, Zookeeper, Kafka, RabbitMQ, Hbase, MongoDB Cassandra, design patterns, load balancing, databases, consistency algorithms, JAVA algorithms, data structures, algorithms, distributed caching, Hadoop, Spark, Storm
Interview treasure book + books + core knowledge acquisition: please forward it and add assistant Vx: Yunduoa2019 after paying attention to it or scan the qr code below and follow the guidance of the assistant to obtain it by yourself
** Interview bible + books + core knowledge acquisition: ** Please forward it, add assistant Vx: Yunduoa2019 after attention or scan the qr code below, follow the guidance of the assistant to obtain by yourself
