Case study: Amazon Vancouver AWS woman event

Dec. 21, 2019

Introduction

I attended the event on Dec. 17, 2019 in the city of Vancouver. I am 53 years old, and most of people showing up 80% are younger than me. Some of them just started their career. I like to do a short case study on this event.

Case study

One of question is to ask how to start software engineer career after working 10 years, career transition to computer science. Another question is about performance review.

I understood that it is so important for me to acquire some skills, which I am weak in those areas. Project management skills, communication skills, cognitive abilities.

For me, since I am working on personal finance research starting from Nov. 2018. First question coming to my mind is to figure out how an Amazon manager who works there over 20  years manage the wealth. Does she manage by herself or hire a portfolio manager? That can be huge amount of wealth, stock double double and double, I may miss a lot of double over there. ROSS stock 40 times more after 20 years.

Also I need to find a role model who chose to leave USA, came back to Canada, how does she manage the successful career.

There is no surprise. I had chance to meet people and ask questions.

I need to get organized. I need to study hard, learn a little and benefit whole life.

Two managers I have chance to write down names. Kim Thunen, another one is Salimah Addetia.

Video:Bogleheads® investment philosophy

Dec. 21, 2019

Introduction

It was such great teaching through those videos. I learned first time how to make hedge using two companies, bath suits inc and umbrella inc, which is related to how to manage risk topic.

My study

What I like to do is to watch each video, and write one blog for each video. I like to look into some concept and idea from the teaching of video.

I like to watch videos from the link.

Case study: CSS position:absolute

Dec. 20, 2019

Introduction

It is the bug I created since I did not notice that the special case at work. Recently I added some margin in the website, and then if there is seven items, then last item will not displayed properly. I did not notice the issue until some one in the office told me so.

Case study

I quickly fixed the issue since I like the child div can have bigger width than parent div. So I learned from stackoverflow.com one question, the answer is to use CSS position:absolute.

My question to myself is to work on CSS by reading more often the tutorial. I should try to push myself to improve my CSS by actively reading the website.

The way I learn about CSS is not proactive. I should prepare myself to be expert one day in CSS.

Here is the website.

grid_10 class is defined the width of parent div - 820, total width 1008 for 12 grid, 82px for each grid.

Now the child div has more than 840 px.

Actionable items

I like to figure out how to master CSS, so I can have time to work on restful webservice, and framework for the front end.

40 business books everyone must read to be successful

Dec. 20, 2019

Introduction

I like to find a few business books to read from those 40 business books.

40 business books

Here is the article.

Restful Web Services

I plan to read the book in short future. I need to push myself to read a book, at least I can understand the ideas. It is hard for me to practice restful web services, but I should be able to find the book and start to read it.

I got the advice from the article here.

Follow up

First two hours study on January 9, 2020

Zalando: How to pass the interview

Here is the article.

Excerpt:

For the API design, you need a basic understanding of REST and HTTP. It is not expected you know fancy media types or the intricacies of HTTP proxies but you need to know how to structure an API and its data using HTTP and JSON. You should have a look at the Richardson’s maturity model (till level 2) and perhaps have a quick look at his book, RESTful Web Services. (Richardson’s newer book, RESTful Web APIs, deals with REST level 3, i.e. hypermedia controls, which is more advanced and out of scope for the interview)

Actionable Items

I just could not believe that I should read restful web services book much early, I work full time from 2010 to 2019. I did not do book keeping every year, I did not read web services book every year from 2010 to 2019. 

This life style is ridiculous, I just could not believe that I did make choice. 

Facebook interview: How I got an offer

Here is the article.

Michael LeBoeuf: The Bogleheads' Guide to Investing Book Summary

Here is the link.

Book to read: The Boglehead's guide to investing

Dec. 19, 2019

Introduction

I like to spend hours to read a book called "The boglehead's guide to investing". It is important for me to slow down, instead of watching youtube.com videos, I should be able to find time to read a book, and think about the ideas. It is different from learning from youtube videos.

My schedule 

I like to schedule time to read the book.

Case study: hundreds of hours with relatives on wechat

Dec. 19, 2019

Introduction

It is my personal finance research. In order for me to find time to learn personal finance, I have to learn how to avoid time-consuming activities. One thing I like to work on is to case study the time I spent from 2010 to 2019 on wechat with my relatives in China.

Case study

Once a while, I will always think about what I should do as a sponsor. I will think about my nephew and how I should help and work on his plan in Canada in 2019. After a few months of study, I learn that I have problems to make decisions. I need to find the good book to teach on this, I came cross the book through one of videos.

It take some time for me to learn that I waste my time to worry about things. I should be responsible for myself. As a single person, it is most important lesson for me to learn. How to manage my time? Work on my thoughts, focus on my own business.

To be a learner, I have to spend time, I need to track down what I read, and read a book as well.

3 tips to save time

I should think about mutual benefits. If there is no plan, then there is no need to talk.
Do not argue anything with siblings. I did my best to serve my mom as a daughter before my mom passed away in 2017. Now it is time for me to build my own life, work on my own life.

How to plan one week break from Dec 23 - January 1?

Dec. 19, 2019

Introduction

I will have one week break starting from next Monday. I like to figure out how to make plans, what I should do and what I should learn. It is so important for me to enjoy the break, and also make sure that I can learn something from the break.

Case study: Onsite interview with hiring manager on December 16

Dec. 19, 2019

Introduction

It is the first time I learn that I have to work on preparation before onsite interview. I like to write a case study how I should prepare a topic seriously. I should move my focus from algorithm, data structure, system design to present a topic, most challenge in my current job.

Case study

I will write down more later.

Vanguard Index Funds For Beginners In 2020

Here is the link.

I like to learn how to present a topic like Ryan. He explains things so clearly, and I like to learn and imitate how he explains thing. His note is so well-prepared.

What Does the S&P 500 Index Measure and How Is It Calculated?

Here is the link.

The S&P 500 measures the value of the stocks of the 500 largest corporations by market capitalization listed on the New York Stock Exchange or Nasdaq Composite. The intention of Standard & Poor's is to have a price that provides a quick look at the stock market and economy. Indeed, the S&P 500 index is the most popular measure used by financial media and professionals, while the mainstream media and the general public might be more familiar with the Dow Jones Industrial Average.

How the S&P 500 is calculated | Charts that Count

Here is the link.

移民美國：年薪30萬的灣區矽谷軟件工程師是真的嗎？

Here is the link.

RSU - stock price - every year RSU
Sign-on bonus - encourage you to join the company
Relocation fee - from different state/ country
Bonus - cash flow -

Facebook
Salary - average 12.6
Stock: $30,000 - $40,000/ year ( 4 years to distribute $120,000 - $160,000)
Sign on bonus: $20,000 - $100,000
Bonus: $50,000 - $200,000 (10% average)

Total: $200,000 dollars

Linkedin
13.6
50,000 stock
bonus $180,000 - $200,000


Amazon

Google 
$12.7 * 10K
stock 40 - 50 * 10K

移民美國：10萬年薪在灣區矽谷是什麼樣的生活水平？

Here is the link.

$100,000 US dollar salary in Sillicon Valley
After tax, monthly income $5,000 - $6,000 dollar/ month

$2000 - $3000 one bedroom unit - do not share with others
Three meals: $1000 for three meals
$400 auto expenses - insurance, $150/ month, registration $30 - $40/ month
Gas expense $200/ month
Clothing: $100/ month
Travel: $200/ month
401 K - $500

$1000 rent one bedroom - electricity
bicycle to work
food preparation - monthly

时代追光者：张磊

Dec. 19, 2019

Introduction

It is the video I like to share with my roommate from 1984 to 1988 in Shanghai Jiaotong Unversity. My college classmate retired last year, and she has interest in learning how to invest on stock market. I like to find this video, and then notice that I should give a few tags for this video.

Investor Zhang Lei, Princeton university graduate

Here is the link. Zhang Lei's wiki page is here.

Tags added:
Zhang Lei, investor of Tencent, Princeton university investor David F. Swensen

年仅39岁，却头顶美国耶鲁大学校委会成员、中国人民大学校董会副董事长等一系列头衔；身为高瓴资本“掌门”，他管理着来自欧美知名投资机构约50亿美元的资金；去年初因向耶鲁大学捐赠888.8888万美元，他一夜“被出名”……全球媒体竞相约访，张磊却始终低调，“从未接受过任何采访”。

　　4月2日，在郑州参加郑州百年高瓴职业学校揭牌仪式后，为了帮助宣传这所公益学校，让更多的贫困青年获得免费职业教育的机会，张磊破例接受了本报专访。

　　□首席记者 路红 记者 吴战朝 实习生 王菁 文 记者 平伟 图

　　阳光纯净“大男孩”，笑谈成功“秘诀”

　　4月2日下午，春雨初至，张磊出现在郑州百年高瓴职业学校校园，一身休闲装束，一脸诚恳笑容。一下车，他就冒雨参观学校，脚步走遍校园的每一个角落，爽朗的笑声一路陪伴。 

　　揭牌仪式后，他应邀为百年职校的学生们演讲，难以按捺浓厚的乡情：“回到老家，回到河南，我心潮澎湃。”他首先道出一连串的感谢：感谢百年职校的老师，感谢母亲影响了自己一生，感谢家乡的父老乡亲，“感谢祖国的腾飞，让我个人有机会腾云驾雾”……这份真诚和幽默，立刻让学生们轻松起来。

　　与孩子们“分享自己成长的经历”，张磊毫无保留。他说，自己是土生土长的河南人，1990年从驻马店地区高中毕业，以驻马店文科总分第一的成绩考进中国人民大学国际金融专业；1998年拿着奖学金进入耶鲁大学，三年时间获得MBA和国际关系两个硕士学位；他曾是华尔街最年轻的华人高管之一，2004年又成为纽约证券交易所1792年成立后派驻中国的第一位首席代表；2005年在耶鲁基金的帮助下，成立高瓴资本公司。

Weekly Trader’s Outlook - Stocks pause then bounce on new tariff delays.

Here is the article.

Bull Market Trends

With the most recent SPX high on Monday (12/12), below is an update of the table illustrating how this bull market compares to others in the post WW II era. At 3,930 days in duration, it is now 478 days longer than the internet bull market, but at +368%, it remains second highest with regard to the percentage increase. The SPX would need to reach a level of about 3,500 to exceed the 417% gain of the strongest bull market in history.

2019 YTD performance of the major U.S. equity indices

Here is the 2019 YTD performance of the major U.S. equity indices (as of the close on 12/12/19):

• S&P 500 (SPX)                             +26.4%
• Nasdaq Composite (COMPX)    +31.3%
• Dow Industrials (DJI)                 +20.6%
• Russell 2000 (RUT)                    +22.0%

2019 market performance

Market Performance

Here is the 2019 YTD performance of the market broken down by the 11 market sectors (as of the close on 12/12/19):

1. Info Tech                      +43.1%
2. Communications Svc  +28.9%
3. Financials                     +28.8%
4. Industrials                     +27.0%
5. Consumer Disc             +23.2%
6. Cons Staples                +22.5%
7. Real Estate                   +20.2%
8. Materials                       +20.2%
9. Utilities                         +18.0%
10. Healthcare                     +16.4%
11. Energy                            +5.0%

Source: Bloomberg L.P.

Project management skills

Dec. 18, 2019

Introduction

It is important for me to learn how to communicate. I think that it is more important for me now, since I can write better code. How to work on my project management skills?

One idea

I learned from pluralsight.com writing code for humans, separate CSS from html and JavaScript. I shared the idea at work with my coworker, I will make sure that all style sheets will be in .css file, so she can try various ideas after our initial design together, therefore we will have much better presentation in web page. I also can free some time, I like to try a few frameworks, so I can write a new website for the company.

Work together and build a team

I like to try restful API, MVC, and web service, and VUE.js framework.

My coworker likes the design, she works on marketing. She was very happy, I told her that it is very important skills to learn how to design using CSS. It will take some time to be an expert, every day 30 minutes reading, after one year she will be an expert, and it is very good for her career. Specially it is easy for her, since hear reading skill is above 8.0 in IELTS test.

Last few months, we worked together for a few projects, I always showed her how I make changes, find examples, read CSS tutorial page.

Because we work together, I also learn so many things. It is not easy to come out very good design, we have to go through the learning process, try a few ideas.

Talk about insomnia

My coworker asked me what happened yesterday as a sick day. I told her that I had insomnia. I explained to her that it is better to take a day off. I could not fall asleep until 4 AM.

It is not healthy to stay in the office whole day with only less than 4 hours sleep.

What if I am Capilano suspension bridge park product manager

Dec. 17, 2019

Introduction

It is time for me to write a small research report called what if I am Capilano suspension bridge park product manager. I like to explore all kinds of ideas to bring into more business and play an important role to share Canada culture, forest and nature fascination.

【BigJoe】硅谷的产品经理要有技术背景吗？/Is tech background required for PMs at Silicon Valley?

Here is the link.

【ENG SUB】如何高效管理时间和多重事情/ How to effectively manage time and multiple projects in life?

Here is the link.

筆記： 1.時間邊界set a boundary/時間盒time box： (1)一次錄視頻就是30分鐘，時間到了不管錄得怎樣就是PO上來，所以即使有一點口誤也沒關係。 (2)買車的時候並非做最全面完整的研究，而是在有限的時間找了幾間車行跟車款，然後從中選出最好的。
2.請別人幫忙delegation (1)用leadership鼓舞別人一起跟你做事情，例如請小夥伴幫忙籌備灣區的PM聚會，或是現在 youtube 上面影片的剪輯、圖片、字幕、上傳、宣傳等是請志願者幫忙。
3.提高效率productively，批次batch： (1)跟人吃飯(1次影響1人)→到處演講(1次影響100人↑)→錄製 Youtube 影片分享(1次影響1000人↑) (2)影片一次錄2集，就可節省架設攝影機的setting time
4.取捨 be selective：有時候可以用「積極的拖延」，先把事情放一下，讓子彈飛一會，如果過段時間還是想做，就說明是真愛，是值得去做的事情。

One more sick day in 2019

Dec. 17, 2019

Introduction

It takes some wisdom to understand what is a sick day. How to determine if I should take a sick day leave. I like to take a sick day since I has insomnia this morning. It is better to call one more sick day instead of last sick day.

How to recover from a sick day

I like to go out swimming. I just got up around 11:00 am, and also took a walk around the community.

How to cope with insomnia?

Dec. 17, 2019

Introduction

It is important for me to slow down to allow myself recover from insomnia. Last night I could not fall asleep until 4:00 am. So I decided to take a sick day, I like to learn from this insomnia incident, and understand how to work with my physical concern in my 50s.

Case study

I like to put together 10 activities I did last night. I like to figure out how to prevent insomnia and how to cope with it.

I made the phone call around 8:00 AM, and continued to sleep until 11:00 am.

A friend's advice

Dec. 17, 2019

Introduction

It is something I like to learn. Since I like to build wealth and grow rich, I like to learn from successful friends I have. But they do give out advice to suggest me avoid taking any risk.

Case study

I went to suspension bridge park with my friend who is a principle engineer in Sillicon Valley last Friday. We did discuss my career choice at dinner table in Chinese restaurant, she does not believe that everything will be great if I compete a job in Facebook or startup. She suggested me to think about working as a real estate agent in weekend.

Questions asked:
1. Do you have big project experience?
2. Do you know the boot camp first three months every week you have to complete a project?
3. Can you compete with people in 20s?

I just could not believe that I like to work on coding every day. I also like to be an interviewer on interviewing.io as well. My interest is changing all the time, it used to be hackerrank contest, and then code review stackexchange.com, and then leetcode weekly contest. I just learn how to master some algorithms in my life first time, and I like to use this experience to help me build wealth and grow rich. I am working on personal finance, investment.

I like to work on a few more case study, and see how I can learn how to make good decisions.

Being frugal 

One of ideas is to be frugal. I like to put wealth to work. I already put my saving into S  & P 500 index, and this is the first time I learn that the return is 25% from May to December 2019.

Actionable Items

Confidence is the biggest item I should frequently check. How to build confidence, and learn from my own failure. I should look into this area.

I should not worry about too much about friend's advice. She did fantastic job to connect me with other people and we met in San Francisco before the onsite this August. It is so amazing to get together, two MBA and product managers of Google, Linkedin manager, Apple manager one principle engineer showed up in our dinner party.

Suspension bridge park second visit

Dec. 16, 2019

Introduction

I thought about my weakness in personality. How come I do not have that personality to accumulate million dollars talent through 24 years in north America. I still work on learning how to enjoy life being frugal.

Second visit

I stepped out onsite interview from dialpad office building on melville street. There was a free shuttle bus to suspension bridge park in North Vancouver. I decided to take the bus and visited the park again using my annual pass. I needed to take some time to enjoy the outdoor.

Take selfie 

It is tough to be a person over 50 years old. I learn to work with myself better. One of ideas is to push myself to read more books, visit more places in local area.

I got my Google hat from Oct GHC event in the city of Seattle new lake union office. I just walked outside the building, finished 4th onsite interview in 2019, and then took bus and it only took less than 30 minutes to get the park.

It is so comfortable to stay outdoor and share this great picture with you at the end of 2019.

Second visit I also know the length of bridge, height from the valley bottom, how many weight it can hold.

What if I am the product manager, how much it costs to hang those lighting balls?

I like the rain of Vancouver. I know that there are snow on top of mountain. I should go up the mountain and go skiing.

How We Hire at Google

Here is the link. 

How to: Prepare for a Google Engineering Interview

Here is the link.

Prepare for Your Google Interview: Coding

Here is the link.

Googlers share targeted advice for the coding portions of Google's interview process for technical and engineering candidates, covering tips for communication and collaboration advice, algorithms and data structures, and more! Skip ahead to: 0:24 Communications and Collaboration 1:30 Algorithms and Data Structures 3:17 Coding 4:03 Testing and Error Checking 4:37 Best Practices

Prepare for Your Google Interview: Troubleshooting and Scripting

Here is the link.

Googlers share targeted advice for the troubleshooting and scripting aspects of Google's interview process for technical and engineering candidates. This video will cover tips for communication and collaboration, troubleshooting and scripting, and overall best practices! Skip ahead to: 0:17 Communication and Collaboration 1:06 Troubleshooting 2:41 Scripting 3:37 Best Practices

Verify, scope and reproduce the problem

Diagnosis:

• Examine
• Diagnose
• Treat

System Design - Sharding | Data Partitioning

Here is the link.


Sharding or Data Partitioning: - Sharding is a technique to break up a big database into many smaller parts - Horizontal scaling means adding more machines, which is cheaper & more feasible - Vertical scaling means improving servers - Partitioning Methods: - Horizontal partitioning: - In this we put different rows into different table(db), i.e. rows can be based on location with zip codes, this is also range based sharding - Problem is if range is not choosen carefully, it'll lead to unbalanced servers. - Vertical Partitioning: - In this we divide data to store tables related to a specfic feature to their own servers.i.e. In Instagram, we can have 1 for user profile, 1 for photos, 1 for friend list. - Problem is in case of additional growth, its necessary to further partition a feature specific DB across servers. - Directory based Partitioning: - In this, create a lookup service which knows your current partitioning scheme & get it from DB access code. - To find out a data entry, we query directory server that holds the mapping between each tuple key to its DB server. - This is good to perform tasks like adding servers to the DB pool or change our partitioning scheme without impacting application. - Partitioning Criteria: - Hash-based partitioning: - In this we apply a hash function to some key attribute of the entity we're storing, that gives partition number. - Make sure to ensure uniform allocation of data among servers - Problem is it effectively fixes total number of DB servers, since adding a new server means changing the hash function, which would require redistribution of data & downtime, the workaround is Consistent Hashing. - List Partitioning: - In this each partition (DB server) is assigned a list of values, i.e. APAC, EMEA, US region has respective partition. - Round-robin Partitioning: - One by one assign which ensure uniform data distribution - Composite partitioning: - Combining any of above partitioning schemas to devise a new scheme. i.e First list partitioning with hash partitioning in each. - Common problems with Sharding: - Joins & Denormalisation: - Performing joins on a database which is running on one server is straightforward, but if DB is partitioned & spread across multiple machines, it's not feasible to perform joins that span database shards. - These joins won't be performance efficient. - Workaround is to denormalise the DB so that queries that required joins can be performed on single table. - Referential integrity: - Trying to enforce data integrity constraint suh as foreign keys in a sharded DB can be extremely difficult. Most of RDMS do not support this. - Rebalancing: - When data distribution is not uniform. - When there is lot of load on a particular Shard. In this video, we're going to reveal Sharding used in System Design: - What is Sharding/ Data Partitioning - Sharding Methods - Sharding Criteria - Sharding Challenges

Here’s Why Apple Stock Just Hit Yet Another All-Time High

Here is the article.

Apple stock, which currently trades at $243 per share, is up over 50% so far this year and over 100% in the past three years; the company’s market value has reached nearly $1.1 trillion. 

30 Signs Someone Will Never Become Rich

Here is the article.

30. Terrrified of failure
29. You only work 40 hours per week
28. Public speaking makes  you nervous
27. You avoid talking on the phone
26. You refuse to move
25. Working by the hour
24. A jack of all trades, but a master of none
23. All talk, no action
22. Never reading
21. Being chronically late
20. Waiting for a miracle
19. Not having financial goals
18. Never trying new things
17. Hating your job
16. Seeking approval from others
15. Taking care of others instead of yourself
14. Starting projects and never finishing them
13. Focusing too much on saving
12. You don't have investments
11. Taking advice from other poor people
10. Not believing in yourself
9. Lacking discipline
8. Commuting over an hour to work
7. Buying things you can't afford
6. Pursuing someone else's dreams instead of your own
5. Content with a paycheck
4. Imagining that getting rich is impossible
3. Accepting wrong kinds of feedback
2. Unable to adapt
1. A lack of motivation

My favorite learning is the following:

25 Working by the hour

The only way people truly get rich is to be paid by results, rather than time. Every single human being has the same 24 hours in a day. The rich ones just figure out a way to make money in a short amount of time. They don’t worry about getting paid by the hour. The end result matters much more.

20 Wait for a miracle

Statistically speaking, poor people tend to be religious, and rich people are more likely to be agnostic or atheist.

Case study: Design youtube or netflix

Dec. 15, 2019

Introduction

I like to spend next 30 minutes to read the article called Designing Youtube or Netflix before 12:00 AM. Now it is 8:58 PM.

Author who studies millionaires: How to get rich and then stay rich

Here is the article.

Being rich, or becoming financially independent, boils down to a two-step process:

1. Accumulate wealth
2. Keep the wealth you've accumulated

Getting rich

Daily growth

Rich relationship

Dream-setting

Persistence

Developing a niche

Creating multiple streams of income - create a hedge against failure and poverty. When one stream suffers, the others come to rescue. 

Being patient

Taking calculated risks

Being optimistic and enthusiastic

Controlling your thoughts, emotions and words

community

Staying open-minded

Giving first and getting later

Finishing what you start

Staying healthy

Taking responsibility

Staying rich

put your wealth to work - invest it wisely in stocks, bonds, real estate and other business opportunities. this helps multiply your wealth. 

Watch what you spend

Avoid spontaneous or emotional purchases

Live below your means

Actionable Items

I think that it is important for me to enjoy being frugal. I do not need to take a vacation to fly somewhere. I should stay in the city of Vancouver, and enjoy simple things in life. 

Also it is important for me to learn how to put wealth to work. I have to learn how to invest, and work on my finance literacy. 

One more thing is to count how I spend time on daily activities. I should choose healthy life style. 

Case study: Instagram system design

Dec. 15, 2019

Introduction

It is well-written article how to design instgram. There are 11 pages in grokking system design. I like to take some notes for each page, I just finished the reading of those pages.

Case study

I do believe that best learning is to read the content. I should learn how to read better, and also take some notes if I come cross some concepts, good analysis with explanation.

Simple version of instgram, where a user can share photos and can also follow other uses. The 'News Feed' for each user will consist of top photos from all the people the user follows.

Requirements/ Goals

Functional requirements
1. users should be able to upload/ download/ view photos
2. user can perform searches based on photo/ video titles
3. user can follow other users
4. The system should be able to generate and display a user's News Feed consisting of top photos from all the people the user follows.

Non-functional requirements

High level system design

block storage servers to store photos and also some database servers to store metadata information about the photos.

Database schema

data about users, their uploaded photos, and people they follow.
tables:
Photo
User
UserFollow

RDBMS like MySQL, problems when we need to scale them

A distributed file storage like HDFS or S3

Key-value store

wide-column datastore like Cassandra
relationships - users and photos, who owns which photo
a list of people a user follows

UserPhoto - key is UserID, value will be a list of photoIDs
UserFollow table -

Cassandra or key-value stores in general, always maintain a certain number of replicas to offer reliability. Also, deletes don't get applied instantly, data is retained for certain days (to support undeleting)

I will google Cassandra and have a short review later on.

Component design

web servers have a connection limit, for example 500 connections

To handle this bottleneck we can split reads and writes into separate services. Dedicated servers for reads and different servers for writes to ensure that uploads don't hog the system.

Reliability and redundancy 

multiple copies of each file, multiple replicas of services running in the system.

single point of failure - redundancy removes the possible problem.

Data sharding 

one DB shard is 4TB, and then 178 shards for 712 TB.

append shard number with each PhotoID - 

How to push myself to learn more from onsite interview?

Dec. 15, 2019

Introduction

It is time for me to prepare a checklist, what I can learn more from the onsite interview. I like to move my focus away from myself, and then try to push myself to work on improvement during onsite. As I learn from a talk yesterday, system design interview is like giving out a tech talk, I have to learn how to cover more areas instead of pushing by the interviewer.

Think like a senior engineer

I should always ask clarifying questions. Ask more questions to show interesting, and also explore the algorithm or topic more carefully.

As I learn from the book talking about decision making, I should at least find more than one solution, and two solutions have less risk, three solutions should be perfect; more than three is waste of time. Three solutions will reduce the risk of mistakes, and then choose one of solutions to get into detail.

Mock Product Manager Interview: Improve WhatsApp

Here is the link.

What's it like to be a Program Manager? — Ask a Googler

Here is the link.

Mock Technical Product Manager Interview (Google PM): How Google Docs Works

Here is the link.

Mock Technical Product Manager Interview (Google PM): How Google Docs Works

Here is the link.

Leadership vocabulary learned from Google interview video

Be authentic, transparent, humble,  knowledgeable, challenge some of your choices. You are not expectable most knowledgeable person, but we do expect you to seek out and work with the teams or individuals who are the best-suited partners to solve a problem or make a decision.

I like to write down those terms by alphabetic order:

open mind
go out ways to communicate
status quo
outside the box
project management skills
remain adaptable
open space for creativity

Prepare for Your Google Interview: Leadership

Here is the link.

0:34/ 4:57
We will be evaluating you on:

1. Communication and leadership style
2. Navigating complexity and ambiguity
3. Working with teams
4. Vision
5. Delivering results

1:19/ 4:57
But we do expect you to seek out and work with the teams or individuals who are the best-suited partners to solve a problem or make a decision.

2:10
Explain to us how you handle these situations with understanding and care, how you avoid escalating the issue.

2:61/ 4:57
Have you formulated your team mission?
Who are the users?
What are you solving for?

3:21/ 4:57

Evaluate you project management skills and deliver results
3:27/ 4:57
We'll be looking for:

•  Define clear goals
•  Develop a plan
•  Delegate tasks
•  Manage progress
•  Maintain team focus

We want to understand how you think and how you make decisions, so it's important to explain your thought process during the interview.

Best practice

• Explain
• Clarify
• Improve
• What you learn and how you grow

How to evaluate candidate in behavior interview

Dec. 15, 2019

Introduction

It is my task to write something I learn from Google interview video. The topic is called how to evaluate the candidate. 

Candidate evaluation

. Did the candidate understand the question, including the basic problem?
. Did they ask clarifying questions?
. What relevant information, stakeholders, and variables were considered?
. Did the candidate identify multiple solution options?
. Were they able to reasonably justify why their solution was the best options?
. Did the candidate listen to incorporate any feedback/ hints from probing questions?

Case study: How to plan an event of new Google office opening?

Dec. 15, 2019

Introduction

I like to learn how to make a plan, since I make mistakes recently in Willingdon Chinese small group reunion. I like to use this case study to help me to learn better.

Case study

Here is the video including this case starting from 7:00/ 11:02.

Framework to answer GCA interview

Take a moment before responding
Ask clarifying questions
Share logical assumptions
Show your work
Consider the pros and cons
Think about how you measure success
Tie it back to the role

General cognitive ability interview

Dec. 15, 2019

Introduction

It is interesting topic and I like to look into called GCA interview. It is to test interviewee's general cognitive ability. 

GCA interview

General cognitive ability - GCA interview, behavior interview, past behavior, sample interview question: what did you fail? tell me the time you fail? How to break complex problems into small solvable pieces, thoughtful solutions. 

What is a GCA interview?
Evaluation of your problem solving skills
Insight into your work style
Opportunity to talk through situations you may face at Google

Actionable Items

I need to evaluate myself as a problem solver. 

Prepare for your Google Interview: Tips and Example General Cognitive Ability Question

Here is the link.

How a candidate thinks
Leadership skills
Role-related knowledge
Googleyness - intellectual curiosity

Emerging leadership - how do you come out leadership at job? Take initiative, and

General cognitive ability - GCA interview, behavior interview, past behavior, sample interview question: what did you fail? tell me the time you fail? How to break complex problems into small solvable pieces.

What is a GCA interview?
Evaluation of your problem solving skills
Insight into your work style
Opportunity to talk through situations you may face at Google

3:03/ 11:02
What is Google assessing?
Understanding of the question
Preparation strategy
Ability to identify solutions
Justification for a specific solution
Communication

3:21/ 11:02
What is Google assessing?

Understanding of the question
Preparation strategy
Ability to identify solutions
Justification for a specific solution
Communication

4:16/ 11:02
How to build a strong response

Take a moment before responding
Ask clarifying questions
Share logical assumptions
Show your work
Consider the pros and cons
Think about how you measure success
Tie it back to the role

Thought process

Consider pros and cons
How to measure the success
specific to the role

- Example
Where is office?
Budget
How many people attend?

Assumptions 1, 2 and 3

thoughtful questions
Show your work

Communicate your solution

Measuring success
Sending out a post event survey

Candidate evaluation

. Did the candidate understand the question, including the basic problem?
. Did they ask clarifying questions?
. What relevant information, stakeholders, and variables were considered?
. Did the candidate identify multiple solution options?
. Were they able to reasonably justify why their solution was the best options?
. Did the candidate listen to incorporate any feedback/ hints from probing questions?

Actionable Items

I have to work on this technique how to build strong response. I have to learn the framework to answer the question.

I still have problems to answer behavior question, and answer people's question.

Investment profit review

Top 10 talents I work with in 2019

Top three hard level algorithms in 2019

Top 10 my favorite meetups in 2019

Top 10 habits to review in 2019

Top 10 helpful skills for my full time job

Top 10 exciting projects in 2019

Top 10 wasting-time projects

Top 10 frustrated moments as a software programmer

Top 10 my favorite blogs

Top 10 favorite mock interviews in 2019

Dec. 15, 2019

Introduction

It is a good idea to find top 10 favorite mock interviews in 2019. I like to write down what I learn from the interviewee, and also I like to review the code as well.

Top 10 favorite algorithms in 2019

Dec. 15, 2019

Introduction

It is hard for me to review algorithms in such short time. I decide to work on 24 hours count down. So I like to write a few blogs and work on a few topics. This one is top 10 favorite algorithms in 2019.

Top 10 favorite algorithms

24 hours count down

Dec. 15, 2019

Introduction

I like to run a 24 hours count down project. I like to make a plan first and see how many things  I can work on.

24 hours count down

First thing  I like to do is to go out, and spend time to walk around central park, and also do some grocery shopping.

Next thing is to start to review some algorithms and OO design, and then behavior interview questions.

I can think about going over all linked list algorithms, tree algorithms, graph algorithms.

SOLID principles

Dec. 15, 2019

Introduction

Object-oriented programming is something I like to learn more. One thing I can review is about SOLID principle. Also I like to review the design question 1 + 2 * 3 and how the pattern is applied to solve the problem. I do not have a lot of time to review.

My past blogs about 1 + 2 * 3

 I spent over one hour to review the principles with an example. I like to look into how many more minutes I can spend on to review.

 I am working on 24 hours count down to study.

Here is the link of SOLID principle from my blog.

Why I continue to attend HackerX event?

Dec. 15, 2019

Introduction

It is such great learning experience for me. I attended the HackerX event on Dec. 10, 2019. I like to write a few things I learn through events.

Three things I learned

Difference between RDBMS and HBase

Here is the article.

I like to read the following content, and then get an idea to search for better content. I like to find out why Facebook messenger system design from grokking system design argues that HBase should be used instead of relational database for messages.

HBase –
HBase is a column-oriented database management system that runs on top of Hadoop Distributed File System (HDFS). It is well suited for sparse data sets, which are common in many big data use cases. It is an opensource, distributed database developed by Apache software foundations. Initially, it was named Google Big Table, afterwards it was re-named as HBase and is primarily written in Java. It can store massive amount of data from terabytes to petabytes. It is built for low-latency operations and is used extensively for read and write operations. It stores large amount of data in the form of tables.

Difference between RDBMS and HBase:

RDBMS	HBASE
It requires SQL (structured query language)	NO SQL
It has a fixed schema	No fixed schema
It is row oriented	It is column oriented
It is not scalable	It is scalable
It is static in nature	Dynamic in nature
Slower retrieval of data	Faster retrieval of data
It follows the ACID (Atomicity, Consistency, Isolation and Durability) property.	It follows CAP (Consistency, Availability,Partition-tolerance) theorem.
It can handle structured data	It can handle structured, unstructured as well as semi-structured data
It cannot handle sparse data	It can handle sparse data

Binary Reed–Solomon encoding

I like to spend less than 20 minutes to understand this encoding. Here is the wiki article.

Little Mix - Black Magic (Dance Tutorial) | Mandy Jiroux

Here is the link.

I said so many nos

Dec. 14, 2019

Introduction

It is hard for me to learn how to get most from my limited time after work, in weekends. 

Say nos

I have to say so many nos to avoid time consuming activities. 

I said so many nos to social event and vacation plan. I asked my friend to repair my rental condo in Florida in October 2019, and sent him a payment $300 US dollars. I did not want to fly to Florida and clean the kitchen and bathroom; I offered $850 dollars for rent even the market rate is $1200 US dollars. I like to spend less time to work on rental business and attract best renters as possible. 

I learn that I only have limit time to spend on algorithm and data structure practice. Usually it is perfect time to work on the project since November and December is holiday season. I have to work on basics, make sure that I can strength the foundation and meet the challenge for another business year.