Personal situation: the top 30% of the last 9 undergraduate grades
Duration: 3.14-5.18
In the end, I got an offer from China Merchants Union's financial development post, and I opened it directly
winter vacation stage
Main tasks: reviewing professional courses, perfecting projects, preparing resumes
Due to the epidemic, the winter vacation at the end of 22 was held very early, and the final exam was postponed to the beginning of 23. Just during the winter vacation, I was preparing for the end of the semester and looking for an internship. The main work was to improve the projects I had done before and review the computer network (by the way, I also took time to read it. Looking at the operating system), it can be regarded as laying a little foundation for finding an internship. During the winter vacation, I also spent two days grinding out a decent resume (including writing a written self-introduction based on the resume and briefly listing the various knowledge points involved in the resume), and subsequent revisions of the resume are based on based on this resume.
mid March
Main work: revising resumes, gradually starting to submit resumes, preparing for written interviews
I always felt that I was not prepared enough. Although the spring recruitment started for a while, I have been afraid to submit my resume, and I am in a very entangled state. It wasn't until my classmates passed Ali's side that I began to feel that I couldn't wait any longer, and I officially entered the period of looking for a summer internship. The first resume was voted for Ali. At that time, Niuke was full of Ali’s hrs recruiting people. I felt that I received at least 30 messages from hrs (group sending). At that time, I naively thought that the economy was recovering and Ali would expand its recruitment. ..
Since it was an internal referral by the seniors (by the way, the seniors were also asked to provide interview counseling), I received an interview invitation not long after the delivery. The first interview was directly tortured crazily, and there may be some obstacles in the communication with the interviewer, we often can't understand each other's meaning... It took about 1h20min to ask technical questions on Thursday night, and then I made an appointment with another man The tearing time (it is said that 50% of the written test will be added after the written test) took about 30 minutes. In the end, I died as expected. I heard from the senior that the interviewer was of a relatively high level and the requirements were very strict. During the interview, I often asked me optimization questions (I can’t really optimize it...). Although the result was not satisfactory, at least I have no regrets: I answered the questions well at the time, and tried my best to fool the questions I didn’t know. Through this interview, I really realized my own shortcomings and guided the direction for my future study.
Alibaba-1688-test-side:
Choose a specific module, tell us what the module does, how it is implemented, and what problems you encounter. For example, data storage, how to use it specifically.
You just mentioned the storage of epidemic prevention policies. What is the dimension of epidemic prevention policies? Where is the minimum strength of the policy? (After communication, it is at the city level), where is the large amount of data reflected, whether it is the number of data items or the size
Dozens of policies are stored in the database, what is the primary key?
Besides redis, what is the dimension of the query data, that is, you just mentioned that the data is at the city level, who is the object of using this data
When the first version has not yet been upgraded, what is the usage like, or you found that its efficiency is very poor, and at what stage did you find it?
How does the user implement the query of this policy?
What is the design to show all of them (I think all the data will appear instead of the prefecture-level city)
There will still be some other information falling into the library when the policy is stored, right?
Did you immediately think of redis when you found that its performance was relatively poor, or did you try other optimization strategies, because I just saw your data volume, even if it is 100-level, it is not very large.
If the db itself needs to be optimized, how to do it
Are database indexes used in the design?
The advantages of redis, what made you choose it
(Suddenly remembered master-slave replication, but the interviewer said it was useless
What storage structure does redis use, or what is the key of the key-value pair, and what is the stored content?
What data structures does redis support besides strings
The hotspot problem of redis (assuming that the data will not expire and fail), most of the traffic is on a certain key or certain keys, which may cause any problems
Why did you choose this project for the second project, the number of people, and the role?
Briefly talk about how entity relationship extraction is done
How did the data set come from
All your input data is a paragraph? What is the final output? Is it the only one? Is the original input a piece of text or a sentence? Will each statement be identified to obtain a relationship?
Because you said that your job is to investigate some algorithms, did you say to use the bert+crf algorithm in the end?
If my model training is not very good, for example, the recognition of "Hunan University" is meaningless except for "lake", will there be any effect when calculating this relationship? Assuming that I have identified this entity, and I want to deal with a relationship, how will I do it?
Did you mention that your model uses Google’s model? Does your model need to be trained by yourself?
We are here for the project, let's ask some basic knowledge, I see that you have learned data structures, what is the difference between stacks and queues. Besides storage, what is the difference, such as efficiency
Have you ever used queues and stacks in your daily development?
Two stacks implement a queue (optimization and optimization)
To create a new string, how do you usually do it
Advantages and disadvantages of String StringBuffer StringBulider
Have you ever used it specifically, is there any difference besides thread safety, or from a performance point of view, usage scenarios
Which is faster to create the same string a hundred times
Do you know about the Linux system, where is your project developed, do you know about shell scripts, common Linux commands
Write shell: There is a file under linux, which stores a lot of ip, one ip line, there are many repetitions, I want to count the number of occurrences of each ip
Questions about testing: Do you test yourself when you write code?
Have you done unit testing or know about any tools and frameworks for unit testing?
except junit
Suppose we want to write a unit use case, there must be a checkpoint to write, that is, we need to write an assertion, do you know what an assertion is?
In addition to black box testing, do you know any testing methods? The difference between white box, black box and gray box
Late March to early April
Main tasks: review stereotyped essays, write interviews
After the last interview, I decided to go to a small factory to practice my skills before going to a big factory, but the small factory didn’t even give me an interview opportunity! ! ! In the end, I had no choice but to vote for Ant again (it happened that the senior was asking for a resume in the group). Ant's side has been very smooth since the beginning of the evaluation, especially the regular questions, which can be counted in seconds. The written test also broke out with two questions. The evaluation was very high (we don’t know why hahaha). Anyway, the two interviews went smoothly, and the seniors who helped referrals have already said, "I think you are very stable, and I will treat you to dinner when you come to Hangzhou."
If there is no accident, there will be an accident at this time. After waiting anxiously for a week, the process was automatically terminated by the system. After inquiring, I found out that the two sides had already given it, but the big leader in the group directly hung up, and did not give it to the three sides. Opportunity... I was quite disappointed when I heard the news at the time, but I can accept it after thinking about it, because this department is the core department of Alipay (the interviewer introduced that all the funds flow of Alipay is related to them) and It is Java research and development again, and the competition must be fierce. I guess there are some big names with double 9 in the past.
After these two rounds of interviews, I feel that I still have a lot of confidence. At least there have been leaders who are optimistic about myself hahahaha. The interviewer also gave a lot of pertinent suggestions: such as transforming the project into actual results (patents, software and Papers), focus on learning in practice, etc. It is also from here that I realized that the "bonus items" written on the recruitment website are not just bonus points, but the key points that the interviewer very much hopes you will know, such as: distributed, high concurrency, etc...
Ant-Alipay Business Line-Alipay (China)-Java R&D-side:
Did you just say that the first project is a course design of software engineering? Through this project, what stages do you think a software development cycle is divided into?
What do you think is the core logic of your requirement and what kind of requirement is it?
When modeling this requirement, which tables you have designed in it is what your er model looks like (what is the entity relationship like)
In addition to the user table, which tables are there, and what kind of relationship are these tables (completely forgot)
May I confirm that you designed the tables you mentioned at the beginning?
Let me confirm that when you are doing this research and development, do you think the design of the relationship model between table entities is done at which stage of the entire software development?
I just heard that you did not follow this table completely during the actual research and development, why?
I ask a question about your user table, what information does your user table have?
What is the uniqueness of the user in this table determined (user id)
What is the generation logic of user id?
How to ensure that the id of each user is different
When each user registers, you will generate an id, right? In addition to the algorithm guarantee when you generate an id, are you completely trustworthy in the algorithm or will you further ensure that there will be no errors in the code?
So you completely trust this algorithm to generate an id for him
I see that you use redis as a cache, what information is mainly cached
What are the advantages of redis
Does redis support persistence (support), how is it implemented
I see that you have written an optimistic lock. What kind of logic is optimistic lock mainly used for?
Why not use pessimistic locking
Where do you think your project can be improved?
For such a system, does it actually deal with the database more? I want to talk to you about the transaction of the database. Can you tell me about the characteristics of the transaction?
Scenario question: On Alipay, we transfer money from account a to account b. This process should conform to atomicity and transaction consistency. If the entire process is described through database operations, what steps should it include?
If there is 100 yuan in user a's account at the same time, but two deduction operations of 100 yuan arrive at the same time, how to ensure that one succeeds and the other fails?
Tell me what is the logic and principle of springboot's aop mechanism
Which basic modules does the springboot framework contain (I don’t know)
Have you looked at the basic modules of spring, what are its basic modules?
I think you actually use a lot of tools here. Have you seen some of his source code or underlying implementation (no) in your daily use of these things? If you haven’t, then how did you learn and understand spring?
What is the implementation principle of hashmap in Java?
Is the hashmap thread-safe?
Then let me ask about design patterns, what are the common design patterns?
Tell a case of using design patterns
You have done a mail system based on pop3, tell me what the protocol of pop3 looks like
Talk about the principle of socket communication
If the client connects to the server, how to judge that he successfully established the connection
Do you plan to study in the future?
Choice of internship and work place
why is it sorted like this
Add an algorithm question: Please implement
copyRandomListthe function to copy a complex linked list. In a complex linked list, each node not only has anextpointer pointing to the next node, but also arandompointer pointing to any node in the linked list ornull.
Ant-Alipay Business Line-Alipay (China)-Java R&D-two sides:
This interview was a DingTalk voice call (without recording). I added the interviewer's friend a few days before the interview and made an appointment. This is the best interview I have had so far. The interviewer is very gentle and chats throughout the whole process. I also told some short stories (experiences) in my own learning process, but I still asked two technical questions at the end. Let me realize that the current market will only reach springboot, which is far from enough.
A few more impressive questions~
You just said that you are good at operating systems and computer networks. Why do you say that? Is it because of your higher test scores or what?
The ER model of the database (I asked on the side, but I didn’t know it at the time, so I went to see it)
Optimistic Locking Applications
Information security (mentioned in the resume, but it doesn't mean the same as what he asked) mainly refers to the data security of users, such as how to deal with data when the health code is not used...
I asked what the second project was about.
Why use Google's model
Finally, there are three technical problems, it can be said that they are not very good...
Do you know about distributed locks?
Do you understand thread local?
Learn about concurrent data structures
mid April to early May
Main tasks: broaden the knowledge, learn some distributed related knowledge (cap theory, zookeeper, distributed locks, etc.), crazy written test
Since then, the chances of interviews have decreased, and a few students around me have received satisfactory offers, and they gradually become anxious...Why did they not even have interviews for the gold, silver, and four that were agreed upon? About three to four weeks Only Hang Seng gave a 15-minute interview opportunity (no text), and other departments of Ant got one (by tulle). There are a lot of written exams. I still remember that I took the written exam every night for a week. It was a bit like intensive training in high school... Huazi’s written exam has not yet reached the passing line of others, and he has no chance to soak in the pool. Did not give. I went home once on May 1st, and felt that my parents were even more anxious than me, and even seriously considered the possibility of going abroad to study for a master's degree... It can be regarded as a relatively dark period of time in the process of finding an internship. No one is really anxious when they are in the process, so if you are soaking in the pool, you can think about it from another angle: no news is good news~
Let me mention the bank's technical job interview: Generally speaking, the interview time (15-20min) will be shorter than that of the big factory, and pay more attention to the application ability (for example, the big factory may ask more questions about the network or jvm, and the bank may I prefer springboot and mybatis). Finally, some banks require formal attire to go to work. If you also follow this dress standard for interviews, you may leave a better impression on the interviewer!
Hang Seng - one side
Introduce yourself for a minute
Redis usage scenarios
How to ensure the data consistency between redis and database
Do you know about double deletion of redis cache?
How is the pagination of mybatis-plus implemented
Do you understand the encapsulation and application of the Result tool class?
How is the optimistic locking used by the project implemented?
Scenario question: There are many people grabbing milk tea together, and the lock is added to the action of grabbing or to the milk tea
Ant-Ant Group-CTO Line-Data and Platform Technology Business Group-Intelligent Interactive Technology Department-One Side
The specific role of redis in the project
Redis data structure
How to realize the hash of redis
How to realize the string of redis
Have you understood the redis jump table (no more
Algorithm question two-number product time complexity On (the answer is to use the hash table to find (O1)
It is a variant of the sum of two numbers, but the sum of two numbers was too simple at that time, so I didn’t take a good look at the optimization, and I haven’t seen this usage of the hash table... It’s really hard to think of it if I haven’t seen it.
There are several pictures of the same size, how to store them evenly in three cache servers
mid to late may
Main work: Crazy pen interview, the battle of all rebels should be given a go
It is mentioned above that you are considering going abroad for graduate study, but to study abroad, first, you must have IELTS (English black hole crying), and second, you must at least have a corresponding internship. So, taking advantage of the last chance in May, I voted for all the companies that I could vote for, and what I got in return was a devilish schedule of 7 written tests and 5 interviews a week (there were some that were dropped due to inappropriate time). After a period of eyes-opening algorithm and closed-eyed stereotyped days, I finally saw a glimmer of light.
First, I picked up the QQ browser for an interview, and finally broke the dilemma of not having an interview for a long time. Although the interview questions were difficult, I had a good chat with the interviewer as a whole. I tried my best and admitted. Not long after that, both Meituan and China Merchants Union made appointments for interviews, which finally brought out the state of the interviews: Meituan had one interview on Friday night, which went relatively smoothly, but it was a pity that we had a second interview at 9:00 on Monday morning. During the second interview, I was not in the right condition (fever ing), and my brain was not very bright, so I sent it away; the recruiting office finished the interview on Saturday afternoon, and after the first interview, I immediately made an appointment for the second interview, although I felt that I answered well at the time. , but I don't know the specific recruitment situation of others, and I have been worried for a week. In the end, the result of recruiting unions was oc, and I found out that there were only 30 interns (all positions) in the internship group, and the school was basically 985, and the undergraduate and masters were unknown (in short, they all seemed to be better than me, update: 15 people enrolled, undergraduate 2/ 15), it is a miracle that I can be ranked, I declare that China Merchants Union is the number one factory in my mind! ! !
Tencent-pcg-QQ browser-side
Implementation of optimistic locking (version)
In addition to adding fields to the database, is there any other way (compare and swap)
What is the implementation of CAS (know the spin lock, don't know much)
What are synchronized and lock locks?
The difference between synchronized and lock
What is the difference between adding static and not adding lock
Synchronized optimization with JDK upgrade
Understanding Concurrent Containers
Do you know about AQS?
Do you know about distributed locks?
Is there any way to achieve it besides zookeeper
What is the difference between redis implementation and zookeeper, which one is more reliable (from the perspective of CAP)
How long after the zookeeper master node hangs up, there will be a new one
Has the project been deployed? Views(?)
What is redis used for
Is redis built by yourself? How many nodes are there?
Is the key of the verification code a mobile phone number? It may leak user data. How to improve it (encryption)
What encryption algorithm can do it
What structure is used in the project besides key-value, or what other structure does redis have?
How to achieve a total leaderboard (zset)
Do you know the master-slave replication of redis? How is it realized?
Persistence of redis
The startup process of springboot
How does springboot handle when a request comes (MVC? Which classes have passed?)
How does the project differentiate requests from applets and web pages(?)
HTTP request structure (request header, request body details...) chasing: how to identify different browsers
What is the request header of tcp? How many bytes are in the tcp header?
Thread Pool Parameters
Why did not choose the framework of Netty, choose the native socket
Why choose the buffer thread pool
There are 10,000 users how to set up thread pool (manually created), how to set parameters
You mentioned a thread for each socket. If the socket connection is blocked, will it affect the subsequent socket connection? How to solve it (the limit on the number of server socket connections? I don’t understand it well, I don’t think there will be such a problem)
Besides using the thread pool, is there any way to implement it?
Meituan-Daojia-R&D Platform-iOS-One Side
Didn't introduce myself
Talk about each layer of OSI and its role
Which layer does http belong to
TCP three-way handshake
The difference between get and post
The difference between http and https
How does HTTPS encrypt communication
Composition information of digital certificates (only digital signature + key...)
How to verify the digital certificate (now it is not very clear what he wants to ask, I said the verification process of the digital certificate, but he did not continue to ask, the answer: link )
Knowledge of Design Patterns
Do you understand deadlock?
The difference between threads and processes
When a thread hangs, will it affect other threads?
When a process hangs, will it affect other processes?
How to solve the challenging problems encountered in your project (redis)
Where is the time spent before caching? Is it a url request?
(The interviewer is mainly engaged in ios, and he doesn't know much about redis. He reasoned based on his understanding of the Internet for many years, so my answer may not necessarily be what he wants to know)
redis update strategy
Redis' limitations on large-scale caching
Redis memory elimination strategy
Algorithm: Frog jumping steps (dp)
Meituan-Daojia-R&D Platform-iOS-Second Side
role in the project
java reflection
Java memory management mechanism
Java's class loading mechanism
Generics in Java
I didn't answer well and sent it directly.
Recruitment-Development-First and Second Sides
The first side started at 4:03 p.m., and the overall question-and-answer pace was very fast. The technical questions were over in about ten minutes, and the second side was notified within ten minutes after the interview.
one side
How Spring's AOP is implemented
Implementation of dynamic proxy
When does AOP fail?
You mentioned that you have written a lot of documents. Do you have any summary and specifications when writing documents?
Has multi-threading been useful (yes), the use and parameters of thread pool
Difficulties encountered in the project
Deep Copy and Shallow Copy in Java
When is deep copy used?
do you know anything about hash tables
How is the expansion of the hash table realized?
How to realize the thread safety of the hash table
How to achieve thread safety without locks in Java
What else do you know about distributed locks
Do you know anything about consumer finance?
grades, are you going to graduate school?
Why choose Shenzhen
What do you want to gain from the internship
two sides
Can't remember clearly, no technical issues
score
why looking for a job
Which companies have you met
Difficulties in the project
Understanding of the Union
The rest is about the same as the non-technical questions on one side
Asked back:
How long does it take to get results
Department business
Expectations for the quality of interns
what do interns do
Later, I received an offer and some factory interviews, but I couldn’t move (and the treatment was average) all of them were rejected, so let’s stop here for the summer internship interview! My mission is complete!
experience
A little humble opinion, everyone have fun~
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(When chatting with the Meituan interviewer) The summer internship may not have such high requirements for the students. Everyone has come here since then. Knowing that the level at this stage is not very high, the more important thing may be whether you can communicate with everyone. Friendly communication and friendly relationship. They recruited you as a colleague, and they are likely to be responsible for taking you during the internship. If you are all unhappy during the interview, how can you pass?
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The things on the resume must be fully mastered, and you can even properly "set up" the interviewer, talk about something you are good at, turn the question into a topic, chat, and take the initiative of the interview in your own hands. It is better for the interviewer to start random stereotype questions and answers without knowing what to ask.
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Everyone will inevitably be nervous in the first few interviews. If the interview does not go well, don’t panic. After the interview, review in time, summarize the questions asked by the interviewer, and improve in each interview. It can be imagined as having a chance to chat with an outstanding senior with an annual salary of hundreds of thousands. He will help you check and make up for the gaps. This opportunity is rare!
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Finally, the interview is like a blind date. It does contain a lot of luck. It is a process of two-way choice between the two parties. If the interviewer is indifferent, you don’t have to feel guilty. environment to work?
learning materials
Collection stereotypes:
CS_Notes (compact)
pdai (comprehensive, in-depth)
JavaGuide (basic, suitable for novices)
Kobayashi coding (Main graphics)
Random Thoughts on Code (Algorithms)
Recruitment channels:
Delivery must go to the official website! ! ! Many people on Niuke and boss ignore people, and the experience is extremely poor
Niuke Whistleblower (update recruitment information from time to time)
Small program for school recruitment (seems to have been maliciously reported)
Companies I have invested in:
Some of the companies that have delivered Hang Seng Ali NetEase Guangfa Ctrip Walnut Programming iQiyi Bank of China Jinke oppo vivo Baidu Kuaishou Ant Huawei Jingdong SF Express SHEIN Rainbow Soft Geely China Europe Fund Huya Zhongan Meituan Shangtang UFIDA cvte Oriental Fortune NetEase Youdao Tencent Ping An Bank China Life Everbright Bank Merchants Union 360 Hisense SAIC Jiangsu Bank Ningde Times Beisen Hengfeng Bank Huaxia Fund Kuaishou Ningbo Bank Qi Anxin Tesla Industrial Bank Hikvision GAC TSMC Changan Automobile SAIC New H3C
Finally, I would like to thank the partners who have pushed me all the way. It is really lucky to have a group of partners who share the same goal and work hard together!