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Thread on @signalapp:

28th Nov 2011: A deal is made.

Security researcher @Moxie Marlinspike and Roboticist Stuart Anderson's brainchild, Whisper Systems, will be sold off to Twitter for a nice sum of money. It comes as a surprise because all of Whisper System's services

I'm going to tell you a little bit how we work on features at GitHub. It's simple, but very powerful in my opinion. At GitHub we have a high performance culture.

We are deploying changes almost all the time while keeping the service running and the deployment failure ratio needs to be super low! We are constantly working on new medium/big features, we have frequent deploys and required peer reviews.

How do we know that big features are not conflicting with each other in functionality and in version control. How do we merge the work done in these non-trivial features? How do we do prevent peer reviews slow down our productivity?

With basically two things: split the work in small batches and feature flags. We don't have long-lived feature branches. We do very small changes all the time and deploy them.

We could split a feature in tens or hundreds of PRs, but until it is beta or GA, we don't expose it to users by using feature flags.

If you're interested in DB internals, stop what you're doing and watch @CMUDB Quarantine Talk from Nico+Cesar about @SQLServer's Cascades query optimizer: https://t.co/FCdsbHHEaD

Many talks this semester were good. This one is the best. My thread provides key takeaways

[6:50] Microsoft hired Goetz Graffe in the 1990s to help them rewrite original Sybase optimizer into Cascades. This framework is now used across all MSFT DB products (@SQLServer, @cosmosdb, @Azure_Synapse).

[14:43] The optimizer checks whether it has stats it will need before cost-based search. If not, it blocks planning until the DBMS generates them. This is different than other approaches we saw this semester where DBMS says "we'll do it live!" with whatever stats are available.

[21:05] Their Cascades' search starts small/simple and then they make decision on the fly whether to expand search based on the expected query runtime and performance benefit from more search.

[26:33] They explicitly have a property for Halloween Problem. Operators specify whether they protect from it and then optimizer ensures property is satisfied. This is mindblowing. I have never thought about using the optimizer for this but it makes sense.

Years before Andy Grove was attributed with the phrase:

"Whatever can be done, will be done"

A lot of us technologists assumed this was the case anyway.

It's a truism.

What if we could track every person on the planet in real time?

Or at least everyone in a major city

🤔🔮

So, given someone has this idea.

Then the only question is can it be done.

Well, we're already installing all the tech to do this for autonomous vehicles, drones and smart city infrastructure.

It really wouldn't be a huge leap to do that for people.

But how might that be possible 🤔

Sure we can already do it with phones right, but not everyone has a phone and sometimes the batteries die blah blah.

Could we do it in a way that it was difficult to circumvent, and always active?

Well, maybe we could if we put our thinking caps on about the problem.

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Now I'm going to enter the wild world of wild speculative futurism, so take everything else with a pinch of salt 🧂

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Turns out cell phone towers pinpoint the location of your phone as part of how they work.

And then as you move around you switch from one tower to another.

I think most people get this.

Something like the image below

THREAD: Now that @Amazon @awscloud has announced they will no longer host @parler_app, many have speculated that they will just “find another host.”

Here is why that’s not so simple and what it will likely mean for the app’s future. First, let’s look at where things are...

2/ Google and Apple have removed the app from their app stores, effectively terminating growth on mobile devices. People can still access the (not good) web UI until Amazon terminates them today. CEO Matze has said they may be down “up to a week” while they find new hosting.

3/ Translated to English, that’s code for “we have no idea what’s going to happen next.” No US cloud provider (Microsoft, Google, IBM, Digital Ocean) is likely to touch this, as it could be seen as providing material support for sedition. No CEO or counsel wants to get near this.

4/ They could potentially “roll their own” data center by buying servers and putting them in a co-location facility. But that’s a single point of failure, and many colo providers would be just as likely to decline their business. It would be hard and risky to pursue this.

5/ Imagine, after they sweated like pigs to get this hardware all setup, if they get told their colo provider is booting them. That’s a lot of metal to then move somewhere else. Meanwhile, the user base is deteriorating because chaos and dying apps. They will go to other venues.