Preface:

As usual, LET me introduce myself first. I graduated from Beijing University of Posts and Telecommunications. I joined Xiao Mi in April, 2018. At present, I am a senior Java engineer of Kuaishou, a CSDN certified blog expert (190W+ page views), a lecturer of CSDN College, and a distributor of GitChat.

In March 2020, I participated in the social recruitment interview and won the offers from Ali, Toutiao, Kuaishou, Baidu and Meituan. Of course, some of the companies that have tried (and failed) to get their hands on things include Momo, Monkey Coach and Didi.

Before the release of a simple face classics, feel limited to everyone’s reference significance. Besides, the time for learning and summarizing is shortened after job-hopping, so I have made a summary of the interviews of the above eight companies to share with you.

The highlights of this post include the following:

• The difference between social and school recruitment interview
• The first round of knowledge and direction
• The second round of knowledge and direction
• The third/fourth round of research direction
• The HRBP interview examines the content
• Recruitment interview tips
• Daily learning resource sharing

The body of the

The difference between social recruitment and school recruitment interview:

Let’s start with the college recruitment interview. The interview mainly tests everyone’s understanding and mastery of basic knowledge, data structure and algorithm proficiency. There is less scrutiny of the business logic aspect of the project architecture. This also requires us to master the basic knowledge of each module.

What about social job interviews?

The part of social recruitment interview includes: the mastery of basic knowledge, the understanding of business logic (project), and the future career planning.

In the social recruitment interview, the investigation of the project and the knowledge derived from the project are quite important, which may directly determine the success or failure of the interview.

I personally summed up the differences between school recruitment and social recruitment:

• School recruitment interview values the basis, the full range of non-dead Angle inspection of your basic knowledge, and general inspection of XXX is what? How is XXX implemented?
• During the social recruitment interview, the investigation of the project takes up at least half. In the second or third interview, a detailed communication and understanding of the project will be made, including the business architecture, technical architecture, technical difficulties and bottlenecks of the whole project.
• Social recruitment interviews are so investigated, what is XXX? How is XXX implemented? Why is XXX implemented this way? That is to say, the same knowledge point, more than the school why to achieve so?
• The algorithm of school enrollment may be a little difficult, while social enrollment is relatively simple because of the depth of the project and technology and the limitation of time.

Why is it so difficult to realize XXX in the interview?

Because, in the information we collected on the Internet, the vast majority are ** in introducing what XXX is? How is XXX implemented? ** does not explain why it is implemented this way, and the interviewer may even ask if there is another way to implement it. Or a better way to do it?

This leads to the same knowledge point, the difficulty of the agency recruitment interview may rise straight. In addition, we lack of thinking in daily life and like to memorize questions, which leads to poor performance in social recruitment interviews.

Next, we will give you an introduction according to the knowledge points investigated in the first two or three rounds of the interview.

Social Recruitment Interview: Round 1 (Life and Death)

I don’t know if you have this feeling? The first round of an interview is the real life-or-death aspect, at least in my experience. Even if it is the recruitment interview, the first round still can not escape from the basic knowledge we have learned before.

What is the knowledge point if the college interview is about this? How do you do that? So social recruitment interviews in most cases continue to look at why do you do that?

That is to say, when we brush face classics in cattle, you will feel that the level of this club recruit face classics is good low ah, it is simply the school recruit level, are some simple basic knowledge points. Some of us might even swell up and think that we already know these things.

As everyone knows, the recruitment interview inspection is ** why so realize? ** This problem is not simple, a lot of knowledge points have rotten streets, the Internet just a search, look to understand. However, there has been little in-depth analysis of why this is done. Social recruitment is mainly in the inspection of whether we have carried out in-depth thinking and understanding of some knowledge points.

Next, we look at the next side of the specific investigation form and knowledge points.

Because it is a social recruitment interview, the interviewers will ask us to choose a project that we think can best demonstrate our technical ability to introduce. After you have introduced the business logic of the project, the interviewer will ask us to describe the technical difficulties and technical bottlenecks of the project. It will take about 15-20 minutes to introduce and ask questions about this project.

Then there are three basic knowledge points to ask, what is **? How do you do that? Why do you do that? ** Below is a list of the most frequent basic knowledge points I have encountered during this period. (Attention!! Attention!! Don’t be arrogant, it looks easy, but can you handle three questions in a row??

Multithreaded concurrent programming:

• How to determine the number of threads in a thread pool
• How is a timed thread pool implemented?
• Synchronized, volatile keyword
• Atomicity, visibility and order
• ReentrantLock ReentrantLock
• How ThreadLocal works
• AQS underlying implementation, and ReentrantLock relationship

JVM knowledge:

• Memory partition
• OOM is introduced
• Object allocation and reclamation
• CMS and G1 garbage collector
• Object reachability analysis
• Class loading mechanism
• JVM tuning parameters
• Full GC, Minor GC
• On-stack allocation of objects (JIT compiler)

MySQL > select * from ‘MySQL’

• MySQL Isolation level
• Consistency view
• Log modules: undo log, redo log, and binglog
• Index structure, back table, left-most prefix principle
• Gap lock, phantom read, MVCC
• SQL optimization

Java basis:

• Implementation principles of NIO
• HashMap, HashSet,LinkedHashMap, and ConcurrentHashMap
• Difference between HashCode and equals methods
• RuntimeException Exception Error
• Use of annotations
• Basic data types
• Five common network IO models

Spring&MyBatis:

• Principles of Spring IOC and AOP
• SpringBoot source code interpretation, startup mode, configuration sequence, etc
• The SpringMVC and Spring parent-child container relationship
• Spring’s transaction implementation
• How to customize SpringBoot starter
• The difference between # and $in MyBatis

Network protocol:

• TCP is different from UDP
• How to ensure TCP reliability
• TCP network packet fragmentation and reassembly
• Three handshakes and four waves, state switch
• The ENCRYPTION algorithm used by the SSL handshake protocol has the disadvantages of asymmetric encryption
• Introduction to XSS and CSRF

Redis&Kafka:

• Redis implements distributed locking
• Redis data structure type
• Redis Zset implements delay queue
• How to maintain the skip table
• Redis threading model
• Redis data expiration mode
• Redis persistence
• Cache avalanche, cache penetration, cache breakdown
• Kafka topic, partition, and log file relationship
• Kafka log compression and deletion
• Basic message queuing features

Well, one side of the basic knowledge survey is mainly above these. This process takes about 20 minutes and doesn’t take much to ask, assuming you can answer it well.

The next part belongs to the “hand tearing” algorithm ** part. Fortunately, during the video interview, major companies basically adopt the online video interview method of niu Guest. So, we can just write code that works between interviews. Social recruitment for algorithm investigation is more basic, the author has not encountered particularly difficult algorithm questions in the interview of many companies, here is a simple list of algorithm questions encountered:

• Find the most elements (Meituan)
• Longest public string
• Singleton pattern (Meituan)
• Quicksort (Ali)
• Find the NTH last node in the linked list (headline)
• Merge k ordered lists (quick hand)
• Reservoir (Quick hand)
• Custom implementation of parseDouble method (quick hand)
• A + B + C =0
• Binary tree foreorder traversal (Quick hand)
• A binary tree is converted to a tree with only right nodes by traversing the preceding order (Ape tutorial)
• Traverse the binary tree in zigzags (headline)
• Keep repeating elements in an ordered list only once(Ali, this is very interesting, if you are interested, you can implement it.)
  • Given an ordered list, keep the elements that repeat in the list only once, as given list 1->1->1->2->3->3->4. The result is 1->3. Please write an efficient algorithm
• Use three threads to print A, B, C respectively, according to ABC CBA ABC CBA… In order to print (Ali)

Ok, so for those of you who are prepared, none of these algorithms are too difficult. Later in the resource sharing section, the author will share his own secret algorithm learning rhythm for years to help you prepare for the interview!!

One side concludes:

Social recruitment side (life and death side) easy to hang the first point, is the beginning of the project explained in general, no bright spot. Technical difficulties and technical bottlenecks in the project can not be expressed, and it is easy to give the interviewer a feeling of “this person can not”. As for the basics, we have to think about what is it? How do you do that? Why is this implemented?

Here’s a quick summary: Explain a great project and you’re halfway through an interview.

Recruitment interview: Second round

If you pass the first round of the interview, congratulations, you are actually half way through the interview. Because one side of the interviewer has been in the basic knowledge of you, the second side of the interviewer has to ask more directions. The second interview will also focus on your understanding of the project.

This interview will allow you to move on to one or more projects without the “pressure” of studying the basics. The interviewer will have an in-depth understanding of the project, including its business architecture, technical architecture and technical principles. It probably includes the following technical points:

• Project business architecture, for each knowledge point in the project to expand and question
• Project technical architecture, such as Thrift implementation principle, nGINx related knowledge, etc
• What techniques did the project learn? Or which of the skills learned before can be reflected in the project?
• What is the QPS of the service? How to ensure high availability of services?
• How to limit flow, fuse and degrade service?
• How services are deployed and how databases in each cluster are synchronized
• How much data is in a single table? What is the index structure?
• How to pressure test new services online?
• How to check for memory leaks?
• Troubleshooting method The online interface response times out

Of course, in addition to these more open questions, some interviewers will also examine the basics, depending on the style of the interviewer. However, the second interview will focus on the technical structure of the project and what you can contribute. (PS. Hand tearing algorithm we are unified in front of the introduction, the second round of interview also need hand tearing algorithm oh)

Summary of two aspects:

The second round of interview is not only to examine the grasp of basic knowledge, but more importantly, the actual business logic ability. If you can show that you have a good ability to solve practical online problems in your answer, and have in-depth knowledge of some of the directions in the actual job, you will have a much smoother interview path.

Social recruitment interview: round 3/4

Why put round 3/4 together? Because some companies only have three rounds of technical interviews, and individual companies will have four rounds of technical interviews, much the same, we are unified here to introduce. Having a final round of technical interviews means that the previous interviewer has recognized your basic knowledge and your business logic and problem-solving skills.

This round of interview is basically the business department boss in the interview, the main direction is relatively fixed. The main research directions include:

• Why come out to see an opportunity?
• Some basic information about the original company team
• A brief introduction to the project
• Open system design topics:
  • Queuing system
  • Order system
  • Parking lot system
• Future career planning
• Do you have any hobbies
• What else do you want to know?

How about that? Does it feel lighter? So, do not be afraid of the Boss, the Boss is generally very easygoing, not deliberately to embarrass everyone, especially in front of the round has been a detailed investigation. Can walk to the end, you of all sorts of ability got affirmation basically, big Boss likes you return too late, how can embarrass you? Of course, some object-oriented system design, including the division of each module, the design of the database table structure we still have to consider comprehensively, design out oh, the key is the idea and design ability.

Recruitment interview: HRBP round

Congratulations, if you’ve made it to the HRBP round of interviews, you’re just one step away from making it official. The HRBP interview mainly tests the candidate’s values and motivation. The main issues involved are as follows:

• Which period of time did you enjoy in your previous company? (Note: growth!)
• Why come out now and see an opportunity? What types of opportunities? (To improve, challenge, etc.)
• How would colleagues or friends describe you? (Talk about your good points, helpful, etc.)
• How do you study at ordinary times? Are there any tips? (Reading, official website, project)
• Have you had any idea of the direction we are heading? (Through the previous interview question, I have some understanding, and I will tell you about it.)
• What are your career plans? (Depth and breadth, delve into a certain trust, settle yourself, find interesting technical points, etc.)
• What are some of your strengths? (ha.jpg)
• What opportunities are you looking at right now? Do you have any other offers? (to be honest, so many ^_^)

Yes, you read that right, probably these questions, as long as we have a little preparation for the HRBP interview. The author did not encounter the phenomenon that HRBP eliminated candidates during the interview. If this is the case, it may be that the previous technical interview performance is not good enough, barely reach the score of take or leave. At this time, if there is a better candidate, even after the HRBP interview, it will still be eliminated. So our focus is still on improving our technical capabilities.

Social Recruitment interview skills:

So what are the skills of social recruitment interview? I think skill should always be based on strength. So how do you have power? To sort out and summarize knowledge points by modules, enrich and supplement each knowledge point continuously in daily study and work.

What? You don’t have time to summarize? It doesn’t matter, I will share dry goods resources later, you just need to make up the difference on this basis.

Now that we have some strength, how do we really handle interviews? Here are a few tips.

(1) You need to systematically review the basics before the interview (after all, a round of interviews is what matters). (2) You also need to prepare an introduction before the interview, and dig into technical difficulties and obstacles in the project. (3) During the interview, if you haven’t studied this before, you can directly say, “SORRY, I didn’t study this.” Do not pretend to know what you don’t know, or talk nonsense, which will affect the interview performance. (4) In each round of interview, we can ask the interviewer to introduce the business logic of the department. (5) After the interview, timely write the following, especially in the interview answer mistakes or some knowledge blind spots. Every round of interviews will teach you something.

PS. One more very very important point!! Create a high-quality resume. If I may be rude, some students with poor academic background have written a rubbish resume. Do you think the big factory will give you an interview? Dachang also has dignity, ok?? If you can’t write a resume, why should you try? Please don’t waste the internal push and HR little sister’s time ok??

Here’s another point. If the interviewer is patient enough to tell you about the department and the direction of the business logic during the interview, congratulations, you probably passed the interview and prepare for the next round of interview. On the contrary, a word to introduce the business situation, then your probability is cool cool, a good review interview, prepare for other companies interview.

Daily learning resource sharing

Looks like it’s time to share the dry stuff we’ve been waiting for. What do you want to share? Let’s talk about them one by one. (A family statement, for reference only)

Learning methods:

How to learn? To learn a new technique, we first need to consult some introductory blog tutorials to learn, after a preliminary understanding. Buy a technical book (physical book!!) “, see almost, we go to find some interview topics to check the gaps (by the way can know the key content), if the time is too late or summarize the ability of the poor students, you can buy some special issues to learn, such as cattle special issue.

How does the algorithm prepare?

In student times, the building Lord did not learn well, calculate law ah say in a complete mess. The club recruit job-hopping, the owner of the building in the year before the two months of time, re – study to prepare the common high-frequency algorithm topic. Let’s start with a few blogs:

• Labuladong. Gitbook. IO/algo/the Pal blog inside is very dry!!!!!! I benefit a lot from it.
• Animation algorithm :(a wide) zhuanlan.zhihu.com/c_113766704…
• Five minutes learning algorithm :(wu shi elder brother) www.cxyxiaowu.com/

Speaking of algorithms, why not mention the well-known LeetCode website? Yes, must brush algorithm on top!! But is it really necessary to use sea tactics against the question bank?

NO, at least not for the social interview. School recruitment interview also suggested that the sea of questions on the second priority tactics!! The first priority is here:

• leetcode-cn.com/explore/Inside the discovery Channel next to the question bank!! Here is the classification summary of the highest frequency of the most common and the most important classic interview topic, and the official has helped you sum up, brush brush dry up!!
  

  

Finally, the landlord will also point to the sword Offer above the common algorithm topic over again! Good, at this time of the level, to participate in a social recruitment interview has been very safe, common algorithm topics can pull pull pull, because we have had the idea of the algorithm. Again recommended:

• labuladong.gitbook.io/algo/

Daily private resources

Ha ha, allow me narcissism, I guess the bottom will someone ask: “the building Lord, you so fierce, usually how to learn?” How to learn? Copy the homework and share the dry goods blog website that I have treasured for many years.

• Server-side strongest conclusion: blog.csdn.net/ThinkWon/ar… (Enough is enough, this one will last you three or five years!!)
• Hollischuang:www.hollischuang.com/archives/ca…
• Zhuanlan.zhihu.com/c_116532620…
• www.zhihu.com/people/tobe…
• Yangwenqiang.blog.csdn.net/ (my blog, welcome attention, embarrassed. JPG)

Well, do not continue to recommend, more learning can not move ~

Resources on Niuke:

Niu Guest network above the resources are many, here is a simple recommendation for you:

• www.nowcoder.com/discuss/398… Niuke University (I had the honor to share a live course with you in Niuke University)
• www.nowcoder.com/blog/blogCe… Niuke special issue (the landlord was invited to create a column on niuke network)

Conclusion:

The social recruitment interview, the author also calculate experience, really have the social recruitment interview experience, and achieved good results, in order to give you better to share, this article is probably finished, do not know if you have a little harvest? Ok, without further ado, let’s study together. I hope to establish a relationship with you as both teachers and friends, and learn, exchange and progress together.

PS. If you have any questions, please comment below. The building Lord will see and communicate with us together ha ~ welcome to pay attention to my blog: yangwenqiang.blog.csdn.net/

Quick push inside!!

That’s right, so much for that. How can you forget to push inward? Quick push inside!!

• Club recruit push: www.nowcoder.com/discuss/419…
• Resume delivery: [email protected] Title: Zhang SAN -2 years of experience -Java development speed internal push, after sending my resume, you can add wechat communication, progress can be checked, accept consultation.
• The school recruit/internship push: campus. Kuaishou. Cn/recruit/CAM… Just drop it from here. This is push in. I can see the push in

Pay attention, pay attention

Welcome to pay attention to my cow guest column:Interview questions for Java Development Position, click the picture for details. Java development post high frequency interview question full analysisThe column has 32 sections and has been updated.

The column is divided into 9 modules to analyze the knowledge points in the Java job interview, including general interview skills, Java foundation, Java advanced, network protocol, common framework and algorithm, design mode and so on.

Column series points into the surface of the analysis of the technical principle behind each interview questions, from shallow to deep, step by step, and strive to let everyone master the technical principle behind the interview questions, abandon the bad habits of the back mode.

If it is helpful to you, remember to like ha, welcome everyone to pay attention to my blog, pay attention to the public number (Wenqiang’s technology cabin), learn more technical knowledge, travel with the ocean of knowledge ~