Twitter has changed this approach few times I guess, earlier it used to be simply insert tweet into a collection of tweets, and then when you load use timeline, look up the people they follow and find/merge those tweets. But it's going to create a lots of load on systems. Another approach is to maintain a cache of user's timeline(mailbox of tweets), when user posts a tweet, lookup all the people who follow that user, and insert the tweet into each or their timeline cache. results have be pre-computed, so less load. Both approaches fails when you have folks with lots of followers, so may be they use a hybrid of these approaches. this is Discussed in detail in "Designing Data-Intensive applications" book.
> Both approaches fails when you have folks with lots of followers
The traditional mailbox architectural model can be improved via a few methods though to increase scale.
1. The entire tweet doesn’t need to be duplicated for each follower, only a lookup reference (“ID”) to the tweet.
2. Unlike in a traditional mailbox sense, each user’s timeline is a bounded collection. So rather than maintaining every tweet for every followed user in the timeline, it’s capped to the X most recent.
Canada, Europe, Australia, NZ. There are places with Bay Area style salaries, there are other places with lower salaries - either way, you'll be living a comfortable life since costs will be lower than Bay Area.
You'll universally find a much better healthcare system (e.g. health insurance not tied to your employer), with the exception of the UK. You'll find a humane immigration system that doesn't kick you out if your employer decides to screw you over (again with the exception of the UK). You'll generally have some form of state support if you lose your job instead of being thrown to homelessness. Etc etc. The US is a second world country nowadays.
And any children you might have will be far safer, and at lower risk for severe mental health problems.
None of those places have anywhere near Bar Area salaries: London, by far the city with the highest salaries in the West outside of the US, has salaries that are 70% of the ones you'd get in California before counting a significant amount of extra income and sales taxes and almost similarly ridicolous housing.
On the other hand, the private insurance in the UK that's usually included in big tech companies' work is absolutely top-notch.
In absolute values, those salaries are the highest, but for quality of living, that's largely irrelevant unless your hobbies need large amounts of capital.
For example, in big cities in Europe, you can easily and happily get by without a car, which saves a lot. You have more vacation. No tipping. Easier/more obvious ways to save for retirement. Your kids not having to do active shooter drills at school. Cheaper/free schools and universities. Maternal/paternal leave. Etc, etc.
So if you have a family, or thinking of starting a family, it's worth factoring that stuff in.
> You'll universally find a much better healthcare system (e.g. health insurance not tied to your employer), with the exception of the UK.
The NHS has something of a funding crisis right now, since our government seems to secretly want to privatize it, but it's still better than losing your health insurance if you lose your job.
'"Second World" refers to the former communist-socialist, industrial states, (formerly the Eastern bloc, the territory and sphere of influence of the Union of Soviet Socialists Republic) today: Russia, Eastern Europe (e.g., Poland) and some of the Turk States (e.g., Kazakhstan) as well as China.'
- From Google.
That was because being in US was considered a status symbol until recently. Parents used to feel proud to tell their friends and relatives that my son/daughter is in US, even though deep down they are afraid of ending up alone. I see an Indian eagerly waiting to be picked for the H1B visa similar to the Sausage Party movie where they all wait eagerly at the supermarket thinking outside the door is heaven or something. I agree some of the things (especially pay) are better than in India, but they are loosing a lot. And India is only going to get better (probably in another 10-15 years, lot of things in India will be comparable to what US has currently).
Coming back to the parents, now with all the negative coverage of H1B in Indian media, people have a negative perception of being in US. My visa expired and is in process of renewal. I didn't go to office one day. My dad thought I wasn't going because I was hiding from the authorities since my visa expired. They have been asking me to come back for a while now.
600K Indians out of 1 billion is nothing. Huge number of Indians don't want to leave India. I hope you know that. It becomes more evident once you are in the marriage market. Lot of them are downright reject proposals from people who work in US. Also, I never heard of Canada immigration until 1 year back. Now, a lot of my friends/colleagues are talking about or in the process of applying for the Canadian visa.
And a good number of those who apply for green card don't do it because they want to become a citizen. Its because once you complete a certain stage of green card (I-140), you can continue working in the country. Otherwise, you have to leave once you complete 6 years. They plan to work for 10-20 years, and come back to India and retire nicely with all the money they made in US.
Yeah, they both have their use cases and they can both be popular equally. It's all about looking at the problem in hand and deciding what do you need to solve that problem.
Also if not discussed properly, there is a possibility of trade war.I am all for better VISA policy, but I am sure US doesn't want India to go China route and block american companies or apply more tarrifs(India also has a somewhat populist leader).
We have been using Vagrant, Terraform, Packer, Vault etc from some time. While there are some issues(that's true for many tools), I find these tools helpful. Hack, I used terraform to provision my QA cluster right now :)
