background

A prestigious high school, but in the end it is just a college degree. No background, no trace, three years of fishing in the troubled waters of the pig factory, three years of Android development, monthly wages far below the average market price to eat and drink, today was criticized by the team leader in public.

Recalling the past three years of 996, and looking at the monthly payment of 7.5K on the bank card, I think this salary is not enough! Just leave!

But I didn't expect that this new job would last a year!

Inspiring?

I broke up with my girlfriend because of the resignation. When I told my girlfriend about my resignation, she scolded me, saying that she was blind to see someone like me with good eyes and low hands. His heart is higher than the sky, and his life is thinner than paper.

We have been together for three years, but I didn't expect her to see me in this way. Don't worry about this girlfriend. So we broke up like this.

I want to state here that I did not do this out of impulse, but for my own reasons.

To be honest, I have never been willing to take such a salary in the pig factory. Although the company has ordered that it is forbidden to inquire about the salary of my colleagues, and I have always followed the rules, but if others want to say, should I deliberately plug my ears? It was also from others that I knew that I was an old employee who had worked in the company for three years, and the salary was not as high as that of a new undergraduate intern (hehe, how could someone laugh at me behind it)!

It is undeniable that academic qualifications are really important, but I think technical ability and performance in actual work are the most important issues for the company.

I really don’t know if I made a wrong choice. I feel that Dachang’s academic discrimination is quite serious. I don’t understand why I insisted on Dachang so much, and I don’t know why I insisted on coming to the pig factory.

The year when Naked Ci and my empty window

I have never regretted the resignation, but let me start again, I will not resign as easily. The window period in the next year did have a great impact on my personality, and it can be said to be a kind of growth.

I resigned suddenly. After leaving the company, I started to submit my resume. Although there are not as many interview notices as expected, there are many.

In the year of bare resignation, I participated in more than 200 interviews, both large and small, which can be regarded as a face tyrant in another sense. There are many big companies in these interviews, such as Tencent, Alipay, Taobao, Pinduoduo, OPPO, Kuaishou, Douyin... I have interviewed almost all the slightly famous big companies on the market, except for the pig factory. Although a big man can bend and stretch, there is an old saying: A good horse does not turn his head back.

It was also the interview experience this year that gave me a new understanding of myself. After all, no matter how arrogant and arrogant people are, they will change after being abused by those big factories more than a hundred times.

Fortunately, in the end, I was favored by the goddess of luck and entered Ali under the push of a friend. Although the process was difficult, it was considered exhilarating.

As the Spring Festival approaches, I know that many people have the idea of quitting, and many are preparing for it. However, here, as a person who has had a one-year window period, I still have something to say to everyone

Naked impression

As I said earlier, I don’t regret leaving, because staying any longer is really not a good choice. Only leaving is the right thing to do. But as I said earlier, I will not leave so easily, because I am not ready for the interview and I am not able to meet the new job.

Here, I suggest that you don't be impulsive after you have the idea of leaving, and you must be prepared.

(1) The frequency of job hopping should not be too high (has an impact on finding a job)

Anyone who has dealt with HR knows that during an interview, everyone will be asked a question: how often do they quit.

Generally speaking, companies have certain requirements for the number of job hopping, especially large factories. This is mainly because frequent job hopping will inevitably lead to less precipitation, because it takes time to settle in a new environment.

According to past experience, 3 jumps in 5 years is more difficult to accept, unless you have an outstanding side, or you have done well in every job.

Otherwise, the more you change jobs, the more useless your resume will be. The companies added to the resume information no longer represent your rich work experience, but your cowardly evasive and irresponsible black spots.

(2) Don't speak naked

I remember that I also wrote about my worries about my naked resignation during the window period. Here is a brief talk about why the issue of " don't speak in vain " has been repeatedly emphasized .

First, there must be enough mental tolerance.

Be prepared to be unable to find a job for the next two to three months (or even longer). (I was fine the previous month, but I became anxious afterwards)
During the interview process, you will encounter all kinds of strange interview situations, and you will also face all kinds of "greetings and concerns" from relatives and friends, denial, Frustration, fatigue, self-doubt... these negative emotions are all swarming.
At this time you need to know that it is not that you are not good, but that you are not suitable. Every company has its own style, and you have already subtly established your own unique workplace style in your previous work, so it is almost impossible to find a new company that fits all at once. This is the same as finding a target. reason.

Second, prepare yourself at least half a year of unemployed funds.

There will be work, but it may be slower.
Money is a very magical thing, it is not everything, but without it it will make people crazy. (My family's conditions are average, and this was really a lot of pressure on me at the beginning)
Naked resignation means that you have no income at all before you find your next job, so at this time, you must ensure that you have been out of work for the past few months. Here, you have no worries about money.
Human energy is limited. If you have to worry about food and clothing while looking for a job, it will be worse. So dear friends, please check if your wallet is enough before leaving naked.

Third, make good use of this time to sort out yourself and enrich yourself in a targeted manner.

Before I suggest that you go out with no words, everyone should first think about their current abilities and whether they have the confidence to go out and compete with others. If you quit before thinking about this issue, then you must do this later and make good use of this gap.
Many people may have a few years of work experience in their original unit, but they don't have much actual skills. They can't compete with others when they go outside.
To find a job, experience is one thing, but skills and expertise are the last word. Just like when I was out of work, I went to a training class to upgrade my own technology. This is an investment in yourself.

In the final analysis, naked remarks are an adventure. Some people are "always naked remarks and always feel good", but more people are "naked remarks for a while and always regret." It's not that you resign naked, you are reasonable. In the eyes of interviewers, naked resignation is actually a manifestation of unplannedness. He will even doubt the reason for your resignation and measure your stability after joining. Naked remarks are risky, so be careful when delivering letters!

Fourth, recognize yourself, don’t be blindly confident

Many times, everyone will have blind confidence, especially those who screw screws in big factories. Sometimes they think that big factories are nothing more than that, and they can be regarded as capable people.
Here you need to give everyone a shot. In fact, many times, the halo you have now belongs to the company and the platform. Leaving the company and removing the halo, you may be a weed.
I can be regarded as a person who has learned a lesson. I thought I was a capable person, but in the final analysis, I was just a person who could only screw screws. Afterwards, he could not help but reluctantly stand up.

Interview preparation resource sharing

Architect builds the foundation of language

At present, the mainstream language for Android APP development is the Java language. The biggest feature of the Java language is to increase the possibility of software interaction. It can be said that almost all applications on Android phones are written in the Java language.

Knowledge points:
1. In-depth understanding of Java generics
2. Explaining in-depth explanations
3. Concurrent programming
4. Data transmission and serialization
5. Principles of Java virtual machine
6. Efficient IO

Interpretation of open source framework for design thinking

With the continuous development of Internet companies, there are more and more modules in product projects, and user experience requirements are getting higher and higher. It is more and more difficult to achieve the purpose of small steps and fast iterations, and the application of plug-in technology is born. If there is no plug-in technology, the applications that integrate a large number of "app" such as Meituan and Taobao may be as big as a few g.

Therefore, today's Android mobile development will not be hot-fixed, plug-inized, or componentized, and more than 80% of the interviews will not pass.

Knowledge points:
1. Hot fix design
2. Plug-in framework design
3. Component framework design
4. Picture loading framework
5. Network access framework design
6. RXJava responsive programming framework design

360° all-round performance tuning

In the hands of development engineers at different levels, because of the uneven technical level, even if many mobile phones are running with very high software performance, there will still be lag when opening applications.

In addition, with the iteration of product content, the functions become more and more complex, and the UI pages become more and more abundant, which also becomes an obstacle to smooth operation. In summary, the performance optimization of APP has become a comprehensive quality that developers should have, and it is also a guarantee for developers to complete high-quality application works.

Knowledge points:
1. Design ideas and code quality optimization
2. Program performance optimization
Start-up speed and execution efficiency optimization
Layout detection and optimization
Memory optimization
Power consumption optimization
Network transmission and data storage optimization
APK size optimization

3. Development efficiency optimization
Distributed version control system Git
automated construction system Gradle

4. Project actual combat
Start-up speed and
fluency
The practice of Douyin's APK package size resource optimization practice
Full analysis of Youku responsive layout technology
Network optimization
Mobile Taobao Double Eleven performance optimization project Secret AutoNavi
APP full-link source code reliance analysis to
completely kill the actual combat of OOM Experience sharing
WeChat Android terminal memory optimization practice

Android framework architecture

Android framework architecture (advanced UI+FrameWork source code) This piece of knowledge is currently the most users, and we call it the technology of Android from 2013 to 2016.

Android developers are often familiar with and unfamiliar with this frequently "used" code because they are used to copying code on the Internet: the familiar is dealing with them almost every day and copying the code every day; the unfamiliar is that although with these codes every day Dealing with codes, but I haven't studied the principles of these codes in depth and the connotations in the depths of the codes.

Knowledge points:
1. Advanced UI promotion
2. Android kernel components
3. Essential IPC for large projects
4. Data persistence and serialization
5. Framework kernel analysis**

NDK module development (audio and video development series)

NDK (abbreviation of Native Development Kit) is a software development kit based on a native programming interface that allows you to use C and C++ code in Android applications. The program developed by this tool runs directly locally, not a virtual machine.

In Android, NDK is a collection of a series of tools, mainly used to extend the Android SDK. NDK provides a series of tools to help developers quickly develop C or C++ dynamic libraries, and can automatically package so and Java applications into an apk.

Knowledge points:
1. Introduction to C/C++ developed by NDK
2. JNI module development
3. Linux programming
4. Low-level image processing
5. Audio and video development
6. Machine learning

Flutter learning advanced

2020 is undoubtedly a year in which Flutter technology is in full swing. Now this technology is still very valuable.

Every mobile developer is crazy about the features and concepts of "rapid development, expressive and flexible UI, native performance" brought by Flutter, from super apps to independent apps, from pure Flutter to hybrid stacks, developers We are enthusiastic about exploring and applying Flutter technology in different scenarios, and we are also facing a variety of different challenges.

Knowledge points:
1. Overview of Flutter cross-platform development
2. Building Flutter development environment in Windows
3. Writing your first Flutter APP
4. Getting started with Flutter Dart language system**
……

WeChat applet development

As one of the most popular programming development application scenarios, WeChat applets are very popular in the market, which makes many developers greedy. But for beginners, it's completely at a loss. I don't know what knowledge needs to be learned in the development and production of WeChat applets. Friends in need can refer to this article.

The main points of knowledge in this article:
1. Overview and introduction of
applet 2. UI development of applet
3. API operation
4. Practical combat of shopping mall projects

Interpretation of Android-related source code,
everyone can read this article here: Niu Breaking! Ali P7 tycoon had a blast for half a month, and compiled the Android source code analysis into a 508-page PDF .

The full version of the information has been organized into a PDF file, and interested friends can click here to get it quickly! Hope to help everyone!

Alibaba (Android post) face-to-face sharing: 4 rounds of technical side + HR face

Alibaba (one side)

Self introduction
How to keep the process alive, what to do to prevent the APP from being killed as much as possible, etc.
I asked two algorithmic questions, one is the question of jumping up the stairs, and the other is the linked list to determine whether there is a ring.
Why do I need to rewrite the hashCode method when rewriting the equals method?
Ask how to use AsyncTask?
Event distribution, memory optimization, performance optimization.
Ask rgb_565 bitmap, how many bits does a pixel occupy?
Ask the principle of java memory GC.
What is the architecture of andoird lanucher and what mode is used.
What android applications have been done.
Refresh mechanism of Android View. Event mechanism, memory mechanism.
Handler mechanism problem. Process sharing data.
Application sharing data., Layout usage.
The way of asynchronous operation.

Alibaba (two sides)

Self introduction
Introduce Android's mvc/mvp/mvvm
View event distribution mechanism
How does viewGroup know if the view has consumption events?
Write a singleton mode (explain sync, double lock, volidate in singleton mode)
What are the memory leaks? How to troubleshoot
The way to transfer data is mainly the interface that the custom class needs to inherit.
JNI thread needs to do operations on java VM.
UI performance optimization.
Ask the time complexity of the bubble algorithm? Generics in java?
What do you think about ios and Android and their development prospects.
Ask what do you think are your strengths/disadvantages? Why did you leave the last company? What is your career plan for the next 5 years?
Ask what kind of development language you are familiar with? Do you have experience in Android development?
Algorithm topic:
There are two ordered arrays of A and B (the array elements are not repeated). Given sum, please find all the sequence pairs
A and B whose sum is sum A:[1,4,5]
B:[ 3,4,6]
sum=8
output 1,1,2,0 => because A[1]+B[1]=8 /A[2]+B[0]=8

Alibaba (three sides)

Self introduction
What is the hardest problem you have
Android's handler mechanism
android anr mechanism
android cold start optimization
android weak network optimization
Do you know about android video?
How to load android long pictures
What gradle has used
Algorithm topic: The conversion of a sorted binary tree to an ordered double-linked list requires an increase on the basis of the original tree node.

Alibaba (four sides)

Self introduction
Difficulties in the project (how to solve, what is the solution)
After a version of an app is released, it is found to be stuck. How do you reproduce it? How to know a place to change card, how to know that user changed card in a certain line of code
What are the android animation mechanisms?
The principle of lottie
What should I do with the animation in the live broadcast? To be dynamic, such as gifts can be configured?
Algorithm problem: Find the number of k in the array. Definition of k number: The number is larger than the number located in front of this number, and the number is smaller than the number located behind this number (don't
care about the numbers at the beginning and the end of the array) (Noodle headline encounters) [4,1,3 ,2,7,9,8,10,12]
The k numbers in this array are 7 and 10

HR face

Self introduction
Future career plan
Tell me about my usual learning methods
Which of these learning methods do you think is the most effective?
What do you think are your strengths and weaknesses? How to overcome these shortcomings?
Evaluate the previous interviewer, or whether the previous interviewer impressed you the most
Why do you want to come to ByteDance?
Which products of Byte do you usually use? Any good suggestions?
expected salary
People in Wuhan? What are your thoughts on swapping cities
Do you have anything to ask?

to sum up

Fortunately, my friend’s recommendation allowed me to get Alibaba’s referral quota. I also tried my best to seize the opportunity. In this interview with Alibaba, the most important part to pay attention to is the algorithm. Now big companies really like to ask. Algorithmic questions, if you want to prepare for an interview with a big factory, it is necessary to brush some questions in advance.

#Final
Due to space issues, there are still many algorithmic questions that have not been written, so I have compiled all the detailed questions and answers into a PDF. Friends who need it can click here [answer] I will share it with you for free. Hope to help everyone!

Thirty years in Hedong, thirty years in Hexi, don't bully the young and poor! Big Android does not fall!

It doesn’t matter if you don’t need this salary or your girlfriend, 30 years in Hedong and 30 years in Hexi, don’t bully the young and poor! Big Android does not fall!