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Santiago
@svpino 5 years, 7 months ago 784 views

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Some of the things I've learned in more than 20 years in the tech industry.

You need to hear these.

🧵👇

Listen to more people who don't look like you, don't speak your language, and don't come from the same place you do.

We aren't doing this near enough.

Small habits compound.

No small improvement is too small.

Just aim for something new every day, and you'll be surprised at the end.

Take responsibility.

It doesn't really matter how you feel, I'm sure you could have done better.

Always keep the big picture in mind and never lose the forest for the trees.

Be the person that pulls everyone out of the rabbit holes.

Focus on the final goal, and don't worry too much about how you get there.

Great results will get you farther than processes, but good processes can help you achieve good results.

Be generous with your knowledge.

It's funny how everything you share finds a way to reward you back.

Who you are is more important than who you were.

We all make mistakes. Move on from them and focus on what's coming.

There are no stupid questions.

Ask away!

(There are, however, stupid people with fragile egos that get bothered when others ask. Ignore them.)

Change is the only thing you can always count on. (And death, and taxes, of course.)

Embrace change.

Better is not always best.

People fantasize about perfection, but perfectionism rarely wins.

Shipping more often will give you better odds than gilding the lily.

Learn to say no.

(I can't say this loud enough!)

Be gracious, professional, nice, but say it more.

Make a habit out of learning.

What you know today will be outdated tomorrow.

Make a plan to keep up and follow it... or you'll get behind.

Focus on one thing at a time.

Multi-tasking murders productivity.

(And turn your phone off!)

Job-hoping may be great for your bank account, but it does nothing to improve the impact you make in the world.

(And it looks horrible in your resume.)

Ideas are worth shit. Execution is worth everything.

Don't be the "idea person". Be the one that takes them and runs with them.

Good communication is a fundamental asset.

You can never invest too much in improving it.

(It doesn't matter how technically good you are if you can't properly communicate with others.)

More from Santiago

Santiago
@svpino

My recommendations to start with machine learning math:

• Statistics 110: Probability — Harvard University
• Essence of Linear Algebra — 3Blue1Brown
• Multivariate Calculus — Coursera

Links and 3 additional free resources here: https://t.co/fEmpmRKEvJ

If you are looking for more machine learning content, give me a follow and I’ll keep your feed interesting 😉.

Santiago
@svpino

10 machine learning questions you should be able to answer.

I started experimenting with a questionnaire before interviewing candidates. Applicants submit a video or written answers to apply for the position.

Thread: Let's look at 10 of these questions.

The questionnaire solves a couple of problems:

1. Weeds out candidates that aren't ready for the job.

2. It significantly cuts down the time we spend talking synchronously.

One problem: It requires extra time from the candidate before the phone interview.

Here are some numbers on a job posting before using the questionnaire:

• 249 applicants
• 13 good applications

That's only 5%.

This sucks.

Numbers after using the questionnaire:

• 44 applicants
• 21 good applications

That's 47%.

This is much better.

I look at it this way:

Sooner or later, I'll ask these questions, and the candidate will have to answer them.

I'd rather give them space and the opportunity to think about their answers without any pressure.

Those who can't or don't want to answer won't apply. That's fine.

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Santiago
@svpino

One of the most popular activation functions used in deep learning models is ReLU.

I asked: "Is ReLU continuous and differentiable?"

Surprisingly, a lot of people were confused about this.

Let's break this down step by step: ↓

Let's start by defining ReLU:

f(x) = max(0, x)

In English: if x <= 0, the function will return 0. Otherwise, the function will return x.

If you draw this function, you'll get the attached chart.

Notice there are no discontinuities in the function.

This should be enough to answer half of the original question: the ReLU function is continuous.

Let's now think about the differentiable part.

A necessary condition for a function to be differentiable: it must be continuous.

ReLU is continuous. That's good, but not enough.

Its derivative should also exist for every individual point.

Here is where things get interesting.

We can compute the derivative of a function using the attached formula.

(I'm not going to explain where this is coming from; you can trust me on this one.)

We can use this formula to see whether ReLU is differentiable.

Santiago
@svpino

You gotta think about this one carefully!

Imagine you go to the doctor and get tested for a rare disease (only 1 in 10,000 people get it.)

The test is 99% effective in detecting both sick and healthy people.

Your test comes back positive.

Are you really sick? Explain below 👇

The most complete answer from every reply so far is from Dr. Lena. Thanks for taking the time and going through

Really doesn\u2019t fit well in a tweet. pic.twitter.com/xN0pAyniFS
— Dr. Lena Sugar \U0001f3f3\ufe0f\u200d\U0001f308\U0001f1ea\U0001f1fa\U0001f1ef\U0001f1f5 (@_jvs) February 18, 2021

You can get the answer using Bayes' theorem, but let's try to come up with it in a different —maybe more intuitive— way.

👇

Here is what we know:

- Out of 10,000 people, 1 is sick
- Out of 100 sick people, 99 test positive
- Out of 100 healthy people, 99 test negative

Assuming 1 million people take the test (including you):

- 100 of them are sick
- 999,900 of them are healthy

👇

Let's now test both groups, starting with the 100 people sick:

▫️ 99 of them will be diagnosed (correctly) as sick (99%)

▫️ 1 of them is going to be diagnosed (incorrectly) as healthy (1%)

👇

$Santiago \U0001f1fa\U0001f1f8\U0001f1fa\U0001f1e6$

Santiago 🇺🇸🇺🇦...
@svpino

You are building a binary classification model to determine whether a picture shows a hot dog or not.

Which of the following activation functions is a good candidate for the output layer?

1. Rectifier Linear Unit (ReLU)
2. Leaky ReLU
3. Sigmoid
4. Softmax

Think about it.

The answer:

You could use either Sigmoid or Softmax.

I'm sure most of you picked Sigmoid. It's certainly the best way to approach this problem.

But Softmax is also an option —although unconventional for a binary classifier.

How about the other choices?

ReLU returns its input if positive, zero otherwise. Leaky ReLU is based on ReLU but with a slight slope for negative values.

ReLU and Leaky ReLU will always give us the previous layer output with no modifications if the input is always positive.

This doesn't help us.

Sigmoid has the ability to squash its input into a range that goes from 0 to 1.

This is good because we can now set a specific threshold for the output of a binary classifier.

Here is an example.

Any image with an output equal to or under 0.5 doesn't show a hot dog. Any image with an output above 0.5 shows a hot dog.

Sigmoid makes it very easy.

How about Softmax?

More from Tech

Patrick McKenzie
@patio11

Torn between "I think losing $100 million when someone beats you at security research is pretty much exactly what you signed up for doing yield farming" and "Maaaaaaaybe not the future of finance you were expecting, huh."

How to put this in regular finance terms...

Suppose hypothetically you have an account at a brokerage with some valuable asset in it. You take a margin loan against that asset to fund your normal spending, or pay a tax bill, or maybe buy something at another brokerage.

For reasons known only to the brokerage, they don't denominate your loan in dollars. They denominate it in shares of a money market fund, which are worth $1 +/- epsilon and basically never deviate from that.

And you think "Hmm, I have a large equity cushion against this loan."

One day, a computer system at the brokerage reports, sorta-kinda erroneously, that the value of the money market fund is actually $1.30 per share. The equity cushion is gone. Your valuable asset is sold, at timing you didn't choose, at wrong price, to pay an inflated phantom debt

And your recourse is... probably tweeting at patio11 saying he finds too much joy in this.

Which I don't; I just feel like this is why you don't trust a CPU built out of redstone to build reliable financial infrastructure on top of.

Devdutta
@Devdutta96

Please please please take your cyber security seriously even if you don’t consider yourself a high risk person. Here are a few easy things to start with. 1/n

Switch from WhatsApp to Signal and enable disappearing messages. Most of us cannot stop using WhatsApp entirely but at least turn off back ups to Google Drive or iCloud. 2/n

Do not have private conversations using the messaging service on any social media platform like Facebook, Instagram or Twitter. 3/n

Switch from Gmail to ProtonMail or any other secure email service provider. 4/n

Switch from Google Docs to CryptPad or RiseUp Pad.

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$Tinker \u274e$

Tinker ❎
@TinkerSec

Singing the Blues:
Taking Down an Insider Threat

"I had all of the advantages. I was already inside the network. No one suspected me. But they found my hack, kicked me off the network...

...and physically hunted me down."

Many pentests start from the outside, wanting to see how the perimeter might be breached.

This pentest started from the inside. My client wanted to assume they had already been breached, and, if breached, how far could an attacker go.

Could they stop me once I was inside?

So they snuck me in. Disguised me as a new employee. Gave me a work computer, an ID badge, an account in their system... hell, I even had a cubicle w/my assumed name on it.

The only person who knew who I really was was their CISO. Everyone else thought I was Jeremy in Marketing.

During most of the first morning, I completed onboarding, made introductions, and completed menial tasks.

But I had to act quick. I only had a week onsite. I had to hack their network while not raising suspicion.

So I set about it.

You have to understand... most "Internal Pentests" are straight forward. The hard part is breaching the network, but once you're inside, it's a target rich environment. End of Life computers, default passwords, everyone a Local Administrator...

sumitgarg.eth
@sumitupgarg

I read two-and-a-half decades worth of Jeff Bezos’s Amazon shareholder letters.

It’s like a mini MBA.

Here I’ve pulled out a free guide for startups, investing, marketing, and “web3”🧵

(It’s a thread, not an ebook)

First, why the focus on web3?

It’s the mid 90’s. A 30-year-old Jeff Bezos is trying to raise money for Amazon. And investors are wondering,

“What’s this internet thing?”

Fast forward, the year is 2022, and folks today are wondering,

“What’s web3?”

Now, a little background…

In 1994, Bezos quit a well paying job to start Amazon.

It wasn’t an easy decision. But Bezos used his famous “regret minimization framework.”

In other words, he didn’t want to be 80 and regret not doing what he really wanted to do.

But what did he want?

Bezos didn’t set out to disrupt retail from the outset.

He simply wanted to come up with a business idea based on the internet and then let the internet grow around it while he kept working on it.

Today, that idea is worth $1.7 trillion and counting.

Moving on to the lessons…

Each year since 1997, Bezos has written an annual letter to Amazon shareholders.

These letters reveal a great deal of lessons and secrets behind his massive success.

So what are they?

Robert M. Lee
@RobertMLee

A quick thread on intelligence analysis in the context of cyber threat intelligence. I see a number of CTI analysts get into near analysis paralysis phases for over thinking their assessments or over obsessing about if they might be wrong. (1/x)

Consider this scenario. A CTI analyst identifies new intrusions and based on the collection available and their expertise note that the victims are all banks. Their consumer wants to know when threats specifically target banks (not just that banks are victims).

The CTI analyst has, from their collection, at this time, and based on their expertise enough to make an activity group (leveraging the Diamond Model in this example) that meet's the requirement of their consumer. So what's the problem?

The CTI analyst begins to over think it. "What if I had more collection? Would my analysis change? I really don't *know* they aren't also targeting mining companies in Australia as I don't have collection there."

The analyst knows their analysis is going to be shared. Maybe even public. "What if another team or professional intelligence firm has more collection and ends up noting that it isn't banking specific at all. Banks are victims, not targets. Will my consumer distrust me later?"

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Amit Schandillia
@Schandillia

[THREAD: HISTORY OF THE HINDU TEMPLE]
1/102
Four hours south of Aswan in Lower Nubia, right by the Nile, is a region dotted with temple complexes built more than 3,000 years ago. Some like the temples of Amada, Derr, and Beit el-Wali go as far back as 1500 BC.

2/102
A little further south, not far from the border with Sudan, is another complex dedicated to Ramses II, Hathor, and Nefertari in the village of Ipsambul, better known locally as Abu Sunbul and internationally as Abu Simbel. These go back to the 13th century BC.

3/102
Djeser-Djeseru, also known as the mortuary temple of Hatshepsut in Upper Egypt also dates to 1400 BC. Over 500 years older is the nearby Mentuhotep II, also a mortuary temple. Both were dedicated to the cult of Amun Ra, besides their respective pharaohs.

4/102
Far older is the Ġgantija complex of Malta. Going as far back as 3600 BC, this one comprises of two temples entirely made of stone and enclosed in a stone wall. From the figures therein, it's understood to be a site of some kind of a fertility cult worship.

5/102
Dating from the same period are the limestone megaliths of Ħaġar Qim and Mnajdra, both said to have once hosted ritualistic sacrifices as part of the same fertility cult worship as found in the Ġgantija complex. Malta has some of the oldest temple complexes in Europe.

Sahil
@sahilypatel

Want to do an MBA for free ?

A thread 👇

1) Leadership: Foundations of Teamwork and Leadership

School: wharton

2) Marketing: Marketing Management

School: wharton

3) Microeconomics: Microeconomics for Managers

School:

4) Financial Theory

School:

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Maurice Casey
@MauriceJCasey

I am reading through reams of late-1920s communist poetry and easily my favourite title so far is: "To a Lady who Rejected a Poem about Spring as a Petit-Bourgeois Deviation"

The last lines:
"So here's my hat into the air,
Three cheers for your amazing hair,
For coal mines, and for turbines, too,
For steel, the Comintern and you!"

A not exactly graceful (though possibly satirical) title: "Lines Disassociating Myself from Yessenin and Supporting the Otherwise Unfounded Legend that I am a Foremost Proletarian Writer"

An excerpt:
"Goodbye verses of Yessenin
Goodbye literary slop-
You are not the line of Lenin
You are not the line of WAPP

Never shall I moan a
simple lyric from the heart
I'll devote my new corona
to the proletarian art"

The poet was Joseph Freeman, who published much of his revolutionary verse in the New Masses, a stylish journal of the interwar American literary Left.

Jaya_Upadhyaya
@Jayalko1

DEVI KARUMARIAMMAN, THIRUVERKADU (TN)

Devi is worshipped here as both Swayambhu (self-manifested) and as Parashakti (with 4 arms holding skull,sword,trishul,udukkai/damru).

Here, Muruga got Vel from Devi to fight Suran. So the place was called Vel kadu which became Verkadu.

It is said that there was an anthill here long ago. Devi appeared in the dream of a devotee and asked him to build a shrine at that spot. When the anthill was removed, the swayambhu murti of Devi emerged. So Devi is called Karuvil Illadha Karumari ( not in the womb of mother).

Once, Devi went to Surya in the form of an old woman but Surya neglected her. Devi’s anger made Surya lose his brightness.
To appease her, Surya said that His rays would fall on Her directly twice in a year and touch her feet. Also, Sunday is celebrated as day of Devi Karumari.

There is also a wooden image of Devi (Marachilai Amman) here. Devotees offer locks to her in the belief that She would safe guard their houses.
Temple tank (Thiruchamber Poigai) is said to have been created by Subramanya. Taking dip in it is said to cure skin related disorders.

Panic! in the Discord
@discord__panic

Neo-nazi group #PatriotFront held a photo op in #Chicago last weekend & is currently marching around #DC so it's as good time as any to compile a list of their identified members for folks to watch for

Who are these chuds?

Patriot Front broke away from white nationalist org Vanguard America following #unitetheright in #charlottesville after James Alex Fields was seen with a VA shield before driving his car into a crowd, murdering Heather Heyer & injuring dozens of others

Syed Robbie Javid a.k.a. Sayed Robbie Javid or Robbie Javid of Alexandria,

Happy Monday everyone :-) Let's ring in September by reacquainting ourselves with Virginia neo-Nazi and NSC Dixie affiliate Sayed "Robbie" Javid, now known by "Reform the States". Robbie is an explicitly genocidal neo-Nazi, so lets get to know him a bit better!

CW on this thread pic.twitter.com/3gzxrIo9HD
— Garfield but Anti-Fascist (@AntifaGarfield) August 31, 2020

Antoine Bernard Renard (a.k.a. “Charlemagne MD” on Discord) from Rockville, MD.

https://t.co/ykEjdZFDi6

Brandon Troy Higgs, 25, from Reisterstown,