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Why WhatsApp Only Needs 50 Engineers for Its 900M Users

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Re: Why WhatsApp Only Needs 50 Engineers for Its 900M Users

#211
post #209
post #208

Earlier quoted context omitted.

Err, WhatsApp?

Thanks, I feel dumb. Although that makes his argument "WhatsApp is good because you can use it to keep in touch with friends and family" which is meaningless.

If it makes you feel any better I had the same question and had to look around for context!

Re: Why WhatsApp Only Needs 50 Engineers for Its 900M Users

#212
post #17

> Why WhatsApp Only Needs 50 Engineers for Its 900M Users Answer: because sending short messages from A to B is basically a solved problem. There is even a programming language (Erlang) that was made with this application in mind. The prototypical "Hello World" example for Erlang is a messaging application.

Actually, over lossy links, it's well known to be an impossible problem: https://en.wikipedia.org/wiki/Two_Generals%27_Problem

You are right. But on that level, even breathing is an impossible problem, because the air molecules could statistically bounce out of the room.

Re: Why WhatsApp Only Needs 50 Engineers for Its 900M Users

#213

Earlier quoted context omitted.

I guess "users" is a confusing concept, but a service like Cloudflare would be an example of a more complex application serving that scale of people.

Is cloudflare more complex or less? If I'm connecting through a CF proxy in North America and someone else is connecting through Europe, there's not really any state that needs to be synchronized between us. If I send a message to somebody in Europe, that obviously does need to be synced.

Having tossed the towel in trying to build a global CDN/caching system with relatively few endpoints some years ago, I can tell you that it's very complex. I can't speak to the complexity of something like WhatsApp, and so any comparison would be totally ignorant and anecdotal, but I am guessing that CloudFlare is orders of magnitude more complex than WhatsApp.

Re: Why WhatsApp Only Needs 50 Engineers for Its 900M Users

#214

Basically they're a silicon valley company who've done everything that's exactly the opposite of standard silicon valley advise -- bootstrapped for first few years, complete apathy or even aversion to silicon valley marketing (if you live in the valley and have no foreign connection, you probably didn't even know what whatsapp was before 2012 or so), built for all client platforms simultaneously (including blackberry…

I interviewed with them recently. They claimed their success was due to picking up Erlang.

Our YC company (Heysan, W07) was very similar to WhatsApp except we decided to shim mobile web into the IM networks of that time. We were closing our doors as they were just getting going, and we really liked what we saw of them. At that time we had pretty much re-written everything to be erlang - it definitely makes writing IM software easy to reason about. Interoping with the IM networks was very graceful in erlang.

Re: Why WhatsApp Only Needs 50 Engineers for Its 900M Users

#215
post #204

Earlier quoted context omitted.

That's not evidence that's speculation. They could be using really good tools. Or each of those 50 programmers are 10x more productive than regular programmer (I don't believe in this imo).

The evidence in this case is the fact that they built the company and product with 50 developers. Whether that evidence implies anything about the product's complexity is the speculative part. If the explanation is that every single programmer at WhatsApp is 10x more productive than programmers at similar top companies, then my first question is how did WhatsApp manage to hire such people but Google, Facebook, etc.,…

Would you rather be one of 25,000 engineers at google, or one of 50 at whatsapp? A ton of people would chose the latter just to be in a more important core role. And if we use the acquisition price as a proxy for current market value, the per engineer capita is 20 times better at WhatsApp. I don't have any inside info, but I'm betting any of those engineers that had options are very very happy with their current job.

Re: Why WhatsApp Only Needs 50 Engineers for Its 900M Users

#216
post #160
post #158

Earlier quoted context omitted.

I don't think anyone commenting along these lines on HN is that ignorant. Everyone on here understands that anything executed at the WhatsApp/FB/Instagram sort of scale is going to present all sorts of tough problems and require software engineering know-how in spades. However of all the various applications you could conceivably scale to hundreds of millions of users this is one of the simplest. I do not think ackno…

>However of all the various applications you could conceivably scale to hundreds of millions of users this is one of the simplest. I do not think acknowledging that is cringeworthy at all. What other apps besides social networking and communication apps even get to hundreds of millions of user?

I'll wager the complexity of WhatsApp is not 1% of 1% of Amazon.

Re: Why WhatsApp Only Needs 50 Engineers for Its 900M Users

#217

If this isn't a counter to the inane recruiting requirements of "5 years with language X" I don't know what is: We don’t bring them in specifically because the engineer knows Erlang,” Mahdavi said on Monday. “We expect the engineer to come in and spend their first week getting familiar with the language and learning to use the environment. If you hire smart people, they’ll be able to do that.”

This reminds me of how we have been hiring engineers. We sit them down for a day with a fairly simple task (build a simple web or mobile app, about three screens with a basic data model) but we make sure to give them a language or framework they are unfamiliar with. They have Google, Stack Overflow, and other employees to use as a resource. It's a great way to get to know new hires while seeing how resourceful and in…

This is one of the most interesting interview ideas I've read in a while. I'm sure a lot of people would love a writeup of your experiences with it.

Re: Why WhatsApp Only Needs 50 Engineers for Its 900M Users

#218
post #172

Earlier quoted context omitted.

Why does your phone number change every month?

Because I travel a lot and use local SIM cards.

Whilst abroad, I've used foreign sim cards in my phone and all Whatsapp does is prompt to keep the existing number or change to new number.

Re: Why WhatsApp Only Needs 50 Engineers for Its 900M Users

#219
post #145

Earlier quoted context omitted.

How do you know if an engineer is average vs one of the best? I haven't heard of anyone who has figured out how to measure an engineer's abilities. Some people test algorithms. Others test how often they've shipped things. Most just look for years of experience. A few even test whether you know certain facts.

Interviews!

I haven't heard of a single company that has nailed down interviews. I was going to mention interviews but figured that if you couldn't measure how much an employee contributes, you'd have a much harder time measuring how much a prospective employee could contribute given a much shorter time to test them.

Re: Why WhatsApp Only Needs 50 Engineers for Its 900M Users

#220

Here's part of what I don't get - there are so many government organizations, state and federal, jumping over themselves to provide funding, incubation and support to IT product/app companies across the country claiming it creates jobs when, as this shows, it is entirely possible to operate at incredible scale nowadays with a mere skeleton staff. So why do so many government-run and government-funded programs fawn ov…

Because most of those politicians think Google employs roughly the same number of people that GM used to. Google has about 55k employees [0] and GM at it's peak had about 350k employees [1], a 6 fold difference. GM also had high competition in the marketplace with Ford and others, so the number of autoworkers was likely in the millions for the country. Since the car and the computer are synonymous for 'mental space'…

GM manufactures their cars in their own factories. Electronics is largely made by fab foundries and electronics assemblers like Foxconn. The entirety of a Chevy Cruze is assembled by GM from parts sourced from other companies and GM itself. Apple iPhones are assembled by Foxconn and others. Foxconn is supposed to employ 300,000 people to assemble iPhone 5S in 2013 [1].

[1] http://fortune.com/2013/11/27/by-the-numbers-how-foxconn-chu...

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