Hello, I’m Luffy! Yesterday, when I was sorting out the study materials in the computer, I came across my interview with Ali half a year ago

Note: Everyone’s interview focus is different, there is a lot of randomness, it depends on the content of your resume, and the idea of the interviewer!

I. Resume screening: 2021-6-13

  • Resume writing notes: As far as possible in order to streamline the text clear full range of technology stack, remember don’t write anything (to give priority to with own sure), written in your resume is likely to be the interviewer asked, if only all exposed himself but not very familiar with the contents of the accumulation, the interviewer ask you some questions, don’t answer, Instead of being a plus, this part of the tech stack is a minus.
  • Pay attention to the foundation, not top-heavy: some time ago to help read the resume of some students, resume technology stack plate content is very rich, the technical system is very comprehensive, the common technical stack involved are basically written. The problem is, if the interviewer from the computer network, operating system, as well as the Java foundation, JDK source code, JVM, database index and other aspects of the question, do not know, give the impression of the interviewer is blindly stacking the use of technology stack, not pay attention to the basic skills.
  • Highlights in the resume: for example, the competition awards of ACM, CTF, ICPC and other competitions, and the technical blog can be properly highlighted (if you have a large number of brushed questions and solved questions, you can even add your own Leetcode home page), as well as CET-6, national scholarship, grade ranking, patents and so on.
  • Polish your resume: Make it easier for HR to pass the screening process! If you just write casually, even if you are really very proficient in algorithms, or strong technical ability, the underlying knowledge is very thorough, it is likely to be eliminated in the screening time!

Two, quality test: 2021-6-13

Almost as soon as I sent out my resume, I received a quality test. The test content includes: idiom, verse, table calculation, figure, personality test and so on. This process is not difficult, but it takes a lot of patience

Algorithm written test (60min) : 2021-6-14

There are altogether 4 questions in the written test: an intelligence question involving traceback (the interviewer suggested that it was backtracked, or not written), a binary tree top view (solved), a dynamic programming to solve the backpack problem (solved), a similar to the sword finger offer in the mid stock problem (solved). Compared with the byte pen test, the mid test is mostly hard.

Note: to be on the safe side, I think it is very good to deduct 200~300 questions (tree, linked list, sorting, recursion, backtracking, dynamic planning), focus on brush sword refers to offer, Top100 questions. Brush it repeatedly, efficiently.

Iv. Technical side (40min) : 2021-6-16

  • First, introduce yourself (about 5 minutes, not too long and not too short) ~
  • The JMM memory model is an example of how working memory communicates with main memory, and why the JMM was introduced. Confused, back eight-part essay can, but don’t not understand why and rote memorization!
  • CSDN Blogging questions: When did you start blogging and what did you learn from blogging? How do you teach yourself at ordinary times? Briefly describe your learning experience.

Blogging is important! I’ve been questioned before: “No one reads your blog, so why spend your time writing useless articles?” . Regardless of other people’s comments, we can not only increase our further understanding of certain knowledge, but also with the increase of fans, blogging has brought us some extra benefits and some contacts. In CSDN, we got to know a lot of bogeymen who got BAT Offer in the same junior year. There are also veteran workers with years of experience who can not only learn from them, but most importantly, broaden their horizons.

I always thought that only students from 985-211 prestigious universities or graduate students with advanced degrees could enter BAT factory, while ordinary undergraduate students directly denied themselves. However, this is not the case. In CSDN, I was fortunate to meet a lot of people who were also ordinary undergraduates and got offers from big factories. So don’t be overconfident, don’t underestimate yourself too much, and don’t blindly deny your efforts and efforts until you’ve really tried to get results!

  • Redis: cache breakdown, cache penetration, cache avalanche; How to implement distributed cache without using SETNX?
  • Project related questions: Where are caches in the project, and what are the differences between caches? How did ES-MQ achieve data synchronization, what optimizations were made in the project, and were there any sub-tables involved? Have also done a brief introduction of those projects, it is better to provide a project link, or Gitee warehouse link.
  • FULL GC, YOUNG GC, STW, STW, STW, STW, STW, STW… After talking for more than ten minutes, the interviewer said: “Ok, OK, I know you are familiar with this area, let’s move on to the next question.” (This part of the eight-part essay is very familiar by back, and I have read the book Java Virtual Machine twice haha)
  • Jvm runtime data area dependence, further detailed division of heap and stack and its role? (This section talks about the flow of operations in the operand stack and the local method table. It is interesting to find an example to analyze the results of a wave, such as a++ + ++a +a –).
  • Closing question: What is the most satisfying blog you have ever written on CSDN? Questions related to the internship experience of the last company, what did the internship do, and how did you do the specific task and how long did the internship last?
  • Rhetorical questions: asked about the business type of the department, the technology stack used, etc.

When I received the interview notice over the phone, I was very excited and afraid that I would be abused by the interviewer. After all, this was the second interview of a big factory. I was not fully prepared for the interview last time (naked face), and I was abused all over the body.

V. Technical second surface (40min) : 2021-6-18

  • The second interview changed an interviewer, or let me introduce myself ~
  • Let’s talk about the project. First, introduce the overall architecture of the project, and then ask the actual scenario question: “How can Kafka producers ensure that multiple threads are produced, and consumers consume only one of them?”

“Or the above problem, if the lock (single application can lock to solve, but not distributed), how to solve in distributed environment?” (Distributed lock SETNX).

  • Internship questions: “What content did you work on as an intern at your last company? How did you deal with those issues?”
  • Computer network related issues: TCP three handshake, four wave detailed process, and state transition process, why three handshake? And why do you wave four times? (Eight-part essay)
  • Computer network related questions: UDP and TCP difference, how to use UDP to achieve a simple TCP? (Eight-part essay)
  • JVMS: what are the differences between Java and C++ in terms of execution efficiency and compilation? Why do YOU need a JVM when Java is inefficient? How does Java solve this problem? Have you seen several implementations of just-in-time compilation in the JVM?
  • Open scene question: Did you use the technology stack you learned to realize a solution to a practical need during your school years? Could you tell me how you did it?
  • Operating system related questions: Why are operating systems divided into user mode and core mode?
  • MySQL index data structure, why use B+ tree instead of other data structure? Like Hash tables, B trees, red black trees?
  • Java basic problem: ask a simple problem, JDBC link database process can say it (send points)!
  • Database related questions: What is a table-back query? What is index coverage?
  • Closing question: Are you currently interviewing with any other companies besides Ali?
  • Rhetorical question: skip.

The second side effect is very good! The interviewer is super warm! As soon as the interviewer hung up the phone, HR told me that the interviewer gave you a very good evaluation, and we had a second interview on the spot.) I have to say that CSDN’s blog has added a lot of points to me, an ordinary student who has no competition and no academic qualifications.

The second interview was my most nervous round. When I was nervous, I used auxiliary words. And then… And then… Ha ha, fortunately the interviewer is very warm, soon bring the rhythm of the right!

JDK collection, thread pool, lock, atomic class source code? I am not sure about this, but the interviewer seems to have opened my blog to read the source code of these parts during the interview. I have written a lot of articles, although I can not experience the high-end thinking of Doung Lea, nor can I understand the principle of Doung Lea as deeply as those years of experience. But this part of my preparation time and energy is still relatively long, at least can not be said to be completely read the source code. Interested partners can have a look at my JDK, JUC source analysis column, basically common set source code, CAS, atomic classes, AQS, concurrent set source code, red and black tree, basically have written articles!

Six, technical three (20min) : 2021-6-23

  • Three faces seem to be in charge of the face, just start or first introduce myself ~
  • Let’s briefly talk about the project. Has the project ever been online? Have you ever encountered the situation that the project runs smoothly at the beginning of the launch, but the interface access becomes slower and slower later?
  • Intelligence question 1: How to express 15 minutes for two uneven incense sticks (failed to answer)
  • Puzzle 2: Catch jelly (permutations and combinations questions, easy to answer)
  • Select * from a table where the number of students is 0-60, 60-80, 80-100.
  • How to implement a PRC framework by yourself? (Did not answer the question, I had not learned Netty at that time, and I had not read this part of the interview questions)
  • What courses did you take at university? What books have you read? How long have you been blogging?
  • Dynamic proxy implementation principle, (JDK dynamic proxy and Cglib dynamic proxy)
  • Find all files in a directory that start with a certain letter.
  • In Linux, how to view the last 10 lines of a file and write them to another file.
  • Computer network related issues: HTTPS implementation principle, how to ensure communication security?
  • Computer network related issues: HTTPS connection process
  • What is the difference in design philosophy between Git and SVN? (No answer)
  • Rhetorical question: skip.

Seven, HR surface (10 minutes) 2021-6-28

I was so excited when I received the phone call from HR, but I had already accepted the summer internship at B station and had already arrived in Shanghai, so I didn’t accept the offer of Ali’s summer internship at last. I probably asked some trivial questions, such as when can I come to the internship, the salary during the internship, why I gave up the internship in Ali, and will I choose to come to Ali again if there is a chance?

Eight, summary

I was very satisfied with the overall interview process. The interviewers and HR staff were excellent.

Due to the reason of my online application, my resume was stuck in Ali Health. I haven’t arranged the interview time for me, so my resume has been locked and I can’t send it to other departments of Ali. After reporting the problem to HR, he arranged the interview for me in advance. After passing the second interview, HR and the interviewer helped me to find bosses and recruiters offline. They got my resume back from Ali Health Department (which took a few days) and continued to arrange my third round of technical interviews.

Note: all departments and subsidiaries of a large factory share recruitment information, which will be recorded once hung up, so don’t be unprepared to post without thinking. If an enterprise ecology fails to receive more than three consecutive interviews, consider changing to another company, because a short period of continuous hung up will affect the next interview.