More on Web3 & Crypto
Crypto Zen Monk
2 years ago
How to DYOR in the world of cryptocurrency
RESEARCH
We must create separate ideas and handle our own risks to be better investors. DYOR is crucial.
The only thing unsustainable is your cluelessness.
DYOR: Why
On social media, there is a lot of false information and divergent viewpoints. All of these facts might be accurate, but they might not be appropriate for your portfolio and investment preferences.
You become a more knowledgeable investor thanks to DYOR.
DYOR improves your portfolio's risk management.
My DYOR resources are below.
Messari: Major Blockchains' Activities
New York-based Messari provides cryptocurrency open data libraries.
Major blockchains offer 24-hour on-chain volume. https://messari.io/screener/most-active-chains-DB01F96B
What to do
Invest in stable cryptocurrencies. Sort Messari by Real Volume (24H) or Reported Market Cap.
Coingecko: Research on Ecosystems
Top 10 Ecosystems by Coingecko are good.
What to do
Invest in quality.
Leading ten Ecosystems by Market Cap
There are a lot of coins in the ecosystem (second last column of above chart)
CoinGecko's Market Cap Crypto Categories Market capitalization-based cryptocurrency categories. Ethereum Ecosystem www.coingecko.com
Fear & Greed Index for Bitcoin (FGI)
The Bitcoin market sentiment index ranges from 0 (extreme dread) to 100. (extreme greed).
How to Apply
See market sentiment:
Extreme fright = opportunity to buy
Extreme greed creates sales opportunity (market due for correction).
Glassnode
Glassnode gives facts, information, and confidence to make better Bitcoin, Ethereum, and cryptocurrency investments and trades.
Explore free and paid metrics.
Stock to Flow Ratio: Application
The popular Stock to Flow Ratio concept believes scarcity drives value. Stock to flow is the ratio of circulating Bitcoin supply to fresh production (i.e. newly mined bitcoins). The S/F Ratio has historically predicted Bitcoin prices. PlanB invented this metric.
Utilization: Ethereum Hash Rate
Ethereum miners produce an estimated number of hashes per second.
ycharts: Hash rate of the Bitcoin network
TradingView
TradingView is your go-to tool for investment analysis, watch lists, technical analysis, and recommendations from other traders/investors.
Research for a cryptocurrency project
Two key questions every successful project must ask: Q1: What is this project trying to solve? Is it a big problem or minor? Q2: How does this project make money?
Each cryptocurrency:
Check out the white paper.
check out the project's internet presence on github, twitter, and medium.
the transparency of it
Verify the team structure and founders. Verify their LinkedIn profile, academic history, and other qualifications. Search for their names with scam.
Where to purchase and use cryptocurrencies Is it traded on trustworthy exchanges?
From CoinGecko and CoinMarketCap, we may learn about market cap, circulations, and other important data.
The project must solve a problem. Solving a problem is the goal of the founders.
Avoid projects that resemble multi-level marketing or ponzi schemes.
Your use of social media
Use social media carefully or ignore it: Twitter, TradingView, and YouTube
Someone said this before and there are some truth to it. Social media bullish => short.
Your Behavior
Investigate. Spend time. You decide. Worth it!
Only you have the best interest in your financial future.
Vitalik
3 years ago
An approximate introduction to how zk-SNARKs are possible (part 2)
If tasked with the problem of coming up with a zk-SNARK protocol, many people would make their way to this point and then get stuck and give up. How can a verifier possibly check every single piece of the computation, without looking at each piece of the computation individually? But it turns out that there is a clever solution.
Polynomials
Polynomials are a special class of algebraic expressions of the form:
- x+5
- x^4
- x^3+3x^2+3x+1
- 628x^{271}+318x^{270}+530x^{269}+…+69x+381
i.e. they are a sum of any (finite!) number of terms of the form cx^k
There are many things that are fascinating about polynomials. But here we are going to zoom in on a particular one: polynomials are a single mathematical object that can contain an unbounded amount of information (think of them as a list of integers and this is obvious). The fourth example above contained 816 digits of tau, and one can easily imagine a polynomial that contains far more.
Furthermore, a single equation between polynomials can represent an unbounded number of equations between numbers. For example, consider the equation A(x)+ B(x) = C(x). If this equation is true, then it's also true that:
- A(0)+B(0)=C(0)
- A(1)+B(1)=C(1)
- A(2)+B(2)=C(2)
- A(3)+B(3)=C(3)
And so on for every possible coordinate. You can even construct polynomials to deliberately represent sets of numbers so you can check many equations all at once. For example, suppose that you wanted to check:
- 12+1=13
- 10+8=18
- 15+8=23
- 15+13=28
You can use a procedure called Lagrange interpolation to construct polynomials A(x) that give (12,10,15,15) as outputs at some specific set of coordinates (eg. (0,1,2,3)), B(x) the outputs (1,8,8,13) on thos same coordinates, and so forth. In fact, here are the polynomials:
- A(x)=-2x^3+\frac{19}{2}x^2-\frac{19}{2}x+12
- B(x)=2x^3-\frac{19}{2}x^2+\frac{29}{2}x+1
- C(x)=5x+13
Checking the equation A(x)+B(x)=C(x) with these polynomials checks all four above equations at the same time.
Comparing a polynomial to itself
You can even check relationships between a large number of adjacent evaluations of the same polynomial using a simple polynomial equation. This is slightly more advanced. Suppose that you want to check that, for a given polynomial F, F(x+2)=F(x)+F(x+1) with the integer range {0,1…89} (so if you also check F(0)=F(1)=1, then F(100) would be the 100th Fibonacci number)
As polynomials, F(x+2)-F(x+1)-F(x) would not be exactly zero, as it could give arbitrary answers outside the range x={0,1…98}. But we can do something clever. In general, there is a rule that if a polynomial P is zero across some set S=\{x_1,x_2…x_n\} then it can be expressed as P(x)=Z(x)*H(x), where Z(x)=(x-x_1)*(x-x_2)*…*(x-x_n) and H(x) is also a polynomial. In other words, any polynomial that equals zero across some set is a (polynomial) multiple of the simplest (lowest-degree) polynomial that equals zero across that same set.
Why is this the case? It is a nice corollary of polynomial long division: the factor theorem. We know that, when dividing P(x) by Z(x), we will get a quotient Q(x) and a remainder R(x) is strictly less than that of Z(x). Since we know that P is zero on all of S, it means that R has to be zero on all of S as well. So we can simply compute R(x) via polynomial interpolation, since it's a polynomial of degree at most n-1 and we know n values (the zeros at S). Interpolating a polynomial with all zeroes gives the zero polynomial, thus R(x)=0 and H(x)=Q(x).
Going back to our example, if we have a polynomial F that encodes Fibonacci numbers (so F(x+2)=F(x)+F(x+1) across x=\{0,1…98\}), then I can convince you that F actually satisfies this condition by proving that the polynomial P(x)=F(x+2)-F(x+1)-F(x) is zero over that range, by giving you the quotient:
H(x)=\frac{F(x+2)-F(x+1)-F(x)}{Z(x)}
Where Z(x) = (x-0)*(x-1)*…*(x-98).
You can calculate Z(x) yourself (ideally you would have it precomputed), check the equation, and if the check passes then F(x) satisfies the condition!
Now, step back and notice what we did here. We converted a 100-step-long computation into a single equation with polynomials. Of course, proving the N'th Fibonacci number is not an especially useful task, especially since Fibonacci numbers have a closed form. But you can use exactly the same basic technique, just with some extra polynomials and some more complicated equations, to encode arbitrary computations with an arbitrarily large number of steps.
see part 3
Ashraful Islam
4 years ago
Clean API Call With React Hooks
| Photo by Juanjo Jaramillo on Unsplash |
Calling APIs is the most common thing to do in any modern web application. When it comes to talking with an API then most of the time we need to do a lot of repetitive things like getting data from an API call, handling the success or error case, and so on.
When calling tens of hundreds of API calls we always have to do those tedious tasks. We can handle those things efficiently by putting a higher level of abstraction over those barebone API calls, whereas in some small applications, sometimes we don’t even care.
The problem comes when we start adding new features on top of the existing features without handling the API calls in an efficient and reusable manner. In that case for all of those API calls related repetitions, we end up with a lot of repetitive code across the whole application.
In React, we have different approaches for calling an API. Nowadays mostly we use React hooks. With React hooks, it’s possible to handle API calls in a very clean and consistent way throughout the application in spite of whatever the application size is. So let’s see how we can make a clean and reusable API calling layer using React hooks for a simple web application.
I’m using a code sandbox for this blog which you can get here.
import "./styles.css";
import React, { useEffect, useState } from "react";
import axios from "axios";
export default function App() {
const [posts, setPosts] = useState(null);
const [error, setError] = useState("");
const [loading, setLoading] = useState(false);
useEffect(() => {
handlePosts();
}, []);
const handlePosts = async () => {
setLoading(true);
try {
const result = await axios.get(
"https://jsonplaceholder.typicode.com/posts"
);
setPosts(result.data);
} catch (err) {
setError(err.message || "Unexpected Error!");
} finally {
setLoading(false);
}
};
return (
<div className="App">
<div>
<h1>Posts</h1>
{loading && <p>Posts are loading!</p>}
{error && <p>{error}</p>}
<ul>
{posts?.map((post) => (
<li key={post.id}>{post.title}</li>
))}
</ul>
</div>
</div>
);
}
I know the example above isn’t the best code but at least it’s working and it’s valid code. I will try to improve that later. For now, we can just focus on the bare minimum things for calling an API.
Here, you can try to get posts data from JsonPlaceholer. Those are the most common steps we follow for calling an API like requesting data, handling loading, success, and error cases.
If we try to call another API from the same component then how that would gonna look? Let’s see.
500: Internal Server Error
Now it’s going insane! For calling two simple APIs we’ve done a lot of duplication. On a top-level view, the component is doing nothing but just making two GET requests and handling the success and error cases. For each request, it’s maintaining three states which will periodically increase later if we’ve more calls.
Let’s refactor to make the code more reusable with fewer repetitions.
Step 1: Create a Hook for the Redundant API Request Codes
Most of the repetitions we have done so far are about requesting data, handing the async things, handling errors, success, and loading states. How about encapsulating those things inside a hook?
The only unique things we are doing inside handleComments and handlePosts are calling different endpoints. The rest of the things are pretty much the same. So we can create a hook that will handle the redundant works for us and from outside we’ll let it know which API to call.
500: Internal Server Error
Here, this request function is identical to what we were doing on the handlePosts and handleComments. The only difference is, it’s calling an async function apiFunc which we will provide as a parameter with this hook. This apiFunc is the only independent thing among any of the API calls we need.
With hooks in action, let’s change our old codes in App component, like this:
500: Internal Server Error
How about the current code? Isn’t it beautiful without any repetitions and duplicate API call handling things?
Let’s continue our journey from the current code. We can make App component more elegant. Now it knows a lot of details about the underlying library for the API call. It shouldn’t know that. So, here’s the next step…
Step 2: One Component Should Take Just One Responsibility
Our App component knows too much about the API calling mechanism. Its responsibility should just request the data. How the data will be requested under the hood, it shouldn’t care about that.
We will extract the API client-related codes from the App component. Also, we will group all the API request-related codes based on the API resource. Now, this is our API client:
import axios from "axios";
const apiClient = axios.create({
// Later read this URL from an environment variable
baseURL: "https://jsonplaceholder.typicode.com"
});
export default apiClient;
All API calls for comments resource will be in the following file:
import client from "./client";
const getComments = () => client.get("/comments");
export default {
getComments
};
All API calls for posts resource are placed in the following file:
import client from "./client";
const getPosts = () => client.get("/posts");
export default {
getPosts
};
Finally, the App component looks like the following:
import "./styles.css";
import React, { useEffect } from "react";
import commentsApi from "./api/comments";
import postsApi from "./api/posts";
import useApi from "./hooks/useApi";
export default function App() {
const getPostsApi = useApi(postsApi.getPosts);
const getCommentsApi = useApi(commentsApi.getComments);
useEffect(() => {
getPostsApi.request();
getCommentsApi.request();
}, []);
return (
<div className="App">
{/* Post List */}
<div>
<h1>Posts</h1>
{getPostsApi.loading && <p>Posts are loading!</p>}
{getPostsApi.error && <p>{getPostsApi.error}</p>}
<ul>
{getPostsApi.data?.map((post) => (
<li key={post.id}>{post.title}</li>
))}
</ul>
</div>
{/* Comment List */}
<div>
<h1>Comments</h1>
{getCommentsApi.loading && <p>Comments are loading!</p>}
{getCommentsApi.error && <p>{getCommentsApi.error}</p>}
<ul>
{getCommentsApi.data?.map((comment) => (
<li key={comment.id}>{comment.name}</li>
))}
</ul>
</div>
</div>
);
}
Now it doesn’t know anything about how the APIs get called. Tomorrow if we want to change the API calling library from axios to fetch or anything else, our App component code will not get affected. We can just change the codes form client.js This is the beauty of abstraction.
Apart from the abstraction of API calls, Appcomponent isn’t right the place to show the list of the posts and comments. It’s a high-level component. It shouldn’t handle such low-level data interpolation things.
So we should move this data display-related things to another low-level component. Here I placed those directly in the App component just for the demonstration purpose and not to distract with component composition-related things.
Final Thoughts
The React library gives the flexibility for using any kind of third-party library based on the application’s needs. As it doesn’t have any predefined architecture so different teams/developers adopted different approaches to developing applications with React. There’s nothing good or bad. We choose the development practice based on our needs/choices. One thing that is there beyond any choices is writing clean and maintainable codes.
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Cory Doctorow
2 years ago
The downfall of the Big Four accounting companies is just one (more) controversy away.
Economic mutual destruction.
Multibillion-dollar corporations never bothered with an independent audit, and they all lied about their balance sheets.
It's easy to forget that the Big Four accounting firms are lousy fraud enablers. Just because they sign off on your books doesn't mean you're not a hoax waiting to erupt.
This is *crazy* Capitalism depends on independent auditors. Rich folks need to know their financial advisers aren't lying. Rich folks usually succeed.
No accounting. EY, KPMG, PWC, and Deloitte make more money consulting firms than signing off on their accounts.
The Big Four sign off on phony books because failing to make friends with unscrupulous corporations may cost them consulting contracts.
The Big Four are the only firms big enough to oversee bankruptcy when they sign off on fraudulent books, as they did for Carillion in 2018. All four profited from Carillion's bankruptcy.
The Big Four are corrupt without any consequences for misconduct. Who can forget when KPMG's top management was fined millions for helping auditors cheat on ethics exams?
Consulting and auditing conflict. Consultants help a firm cover its evil activities, such as tax fraud or wage theft, whereas auditors add clarity to a company's finances. The Big Four make more money from cooking books than from uncooking them, thus they are constantly embroiled in scandals.
If a major scandal breaks, it may bring down the entire sector and substantial parts of the economy. Jim Peterson explains system risk for The Dig.
The Big Four are voluntary private partnerships where accountants invest their time, reputations, and money. If a controversy threatens the business, partners who depart may avoid scandal and financial disaster.
When disaster looms, each partner should bolt for the door, even if a disciplined stay-and-hold posture could weather the storm. This happened to Arthur Andersen during Enron's collapse, and a 2006 EU report recognized the risk to other corporations.
Each partner at a huge firm knows how much dirty laundry they've buried in the company's garden, and they have well-founded suspicions about what other partners have buried, too. When someone digs, everyone runs.
If a firm confronts substantial litigation damages or enforcement penalties, it could trigger the collapse of one of the Big Four. That would be bad news for the firm's clients, who would have trouble finding another big auditor.
Most of the world's auditing capacity is concentrated in four enormous, brittle, opaque, compromised organizations. If one of them goes bankrupt, the other three won't be able to take on its clients.
Peterson: Another collapse would strand many of the world's large public businesses, leaving them unable to obtain audit views for their securities listings and regulatory compliance.
Count Down: The Past, Present, and Uncertain Future of the Big Four Accounting Firms is in its second edition.
https://www.emerald.com/insight/publication/doi/10.1108/9781787147003
Gareth Willey
2 years ago
I've had these five apps on my phone for a long time.
TOP APPS
Who survives spring cleaning?
Relax. Notion is off-limits. This topic is popular.
(I wrote about it 2 years ago, before everyone else did.) So).
These apps are probably new to you. I hope you find a new phone app after reading this.
Outdooractive
ViewRanger is Google Maps for outdoor enthusiasts.
This app has been so important to me as a freedom-loving long-distance walker and hiker.
This app shows nearby trails and right-of-ways on top of an Open Street Map.
Helpful detail and data. Any route's distance,
You can download and follow tons of routes planned by app users.
This has helped me find new routes and places a fellow explorer has tried.
Free with non-intrusive ads. Years passed before I subscribed. Pro costs £2.23/month.
This app is for outdoor lovers.
Google Files
New phones come with bloatware. These rushed apps are frustrating.
We must replace these apps. 2017 was Google's year.
Files is a file manager. It's quick, innovative, and clean. They've given people what they want.
It's easy to organize files, clear space, and clear cache.
I recommend Gallery by Google as a gallery app alternative. It's quick and easy.
Trainline
App for trains, buses, and coaches.
I've used this app for years. It did the basics well when I first used it.
Since then, it's improved. It's constantly adding features to make traveling easier and less stressful.
Split-ticketing helps me save hundreds a year on train fares. This app is only available in the UK and Europe.
This service doesn't link to a third-party site. Their app handles everything.
Not all train and coach companies use this app. All the big names are there, though.
Here's more on the app.
Battlefield: Mobile
Play Store has 478,000 games. Few can turn my phone into a console.
Call of Duty Mobile and Asphalt 8/9 are examples.
Asphalt's loot boxes and ads make it unplayable. Call of Duty opens with a few ads. Close them to play without hassle.
This game uses all your phone's features to provide a high-quality, seamless experience. If my internet connection is good, I never experience lag or glitches.
The gameplay is energizing and intense, just like on consoles. Sometimes I'm too involved. I've thrown my phone in anger. I'm totally absorbed.
Customizability is my favorite. Since phones have limited screen space, we should only have the buttons we need, placed conveniently.
Size, opacity, and position are modifiable. Adjust audio, graphics, and textures. It's customizable.
This game has been on my phone for three years. It began well and has gotten better. When I think the creators can't do more, they do.
If you play, read my tips for winning a Battle Royale.
Lightroom
As a photographer, I believe your best camera is on you. The phone.
2017 was a big year for this app. I've tried many photo-editing apps since then. This always wins.
The app is dull. I've never seen better photo editing on a phone.
Adjusting settings and sliders doesn't damage or compress photos. It's detailed.
This is important for phone photos, which are lower quality than professional ones.
Some tools are behind a £4.49/month paywall. Adobe must charge a subscription fee instead of selling licenses. (I'm still bitter about Creative Cloud's price)
Snapseed is my pick. Lightroom is where I do basic editing before moving to Snapseed. Snapseed review:
These apps are great. They cover basic and complex editing needs while traveling.
Final Reflections
I hope you downloaded one of these. Share your favorite apps. These apps are scarce.
Christian Soschner
3 years ago
Steve Jobs' Secrets Revealed
From 1984 until 2011, he ran Apple using the same template.
What is a founder CEO's most crucial skill?
Presentation, communication, and sales
As a Business Angel Investor, I saw many pitch presentations and met with investors one-on-one to promote my companies.
There is always the conception of “Investors have to invest,” so there is no need to care about the presentation.
It's false. Nobody must invest. Many investors believe that entrepreneurs must convince them to invest in their business.
Sometimes — like in 2018–2022 — too much money enters the market, and everyone makes good money.
Do you recall the Buy Now, Pay Later Movement? This amazing narrative had no return potential. Only buyers who couldn't acquire financing elsewhere shopped at these companies.
Klarna's failing business concept led to high valuations.
Investors become more cautious when the economy falters. 2022 sees rising inflation, interest rates, wars, and civil instability. It's like the apocalypse's four horsemen have arrived.
Storytelling is important in rough economies.
When investors draw back, how can entrepreneurs stand out?
In Q2/2022, every study I've read said:
Investors cease investing
Deals are down in almost all IT industries from previous quarters.
What do founders need to do?
Differentiate yourself.
Storytelling talents help.
The Steve Jobs Way
Every time I watch a Steve Jobs presentation, I'm enthralled.
I'm a techie. Everything technical interests me. But, I skim most presentations.
What's Steve Jobs's secret?
Steve Jobs created Apple in 1976 and made it a profitable software and hardware firm in the 1980s. Macintosh goods couldn't beat IBM's. This mistake sacked him in 1985.
Before rejoining Apple in 1997, Steve Jobs founded Next Inc. and Pixar.
From then on, Apple became America's most valuable firm.
Steve Jobs understood people's needs. He said:
“People don’t know what they want until you show it to them. That’s why I never rely on market research. Our task is to read things that are not yet on the page.”
In his opinion, people talk about problems. A lot. Entrepreneurs must learn what the population's pressing problems are and create a solution.
Steve Jobs showed people what they needed before they realized it.
I'll explain:
Present a Big Vision
Steve Jobs starts every presentation by describing his long-term goals for Apple.
1984's Macintosh presentation set up David vs. Goliath. In a George Orwell-style dystopia, IBM computers were bad. It was 1984.
Apple will save the world, like Jedis.
Why do customers and investors like Big Vision?
People want a wider perspective, I think. Humans love improving the planet.
Apple users often cite emotional reasons for buying the brand.
Revolutionizing several industries with breakthrough inventions
Establish Authority
Everyone knows Apple in 2022. It's hard to find folks who confuse Apple with an apple around the world.
Apple wasn't as famous as it is today until Steve Jobs left in 2011.
Most entrepreneurs lack experience. They may market their company or items to folks who haven't heard of it.
Steve Jobs presented the company's historical accomplishments to overcome opposition.
In his presentation of the first iPhone, he talked about the Apple Macintosh, which altered the computing sector, and the iPod, which changed the music industry.
People who have never heard of Apple feel like they're seeing a winner. It raises expectations that the new product will be game-changing and must-have.
The Big Reveal
A pitch or product presentation always has something new.
Steve Jobs doesn't only demonstrate the product. I don't think he'd skip the major point of a company presentation.
He consistently discusses present market solutions, their faults, and a better consumer solution.
No solution exists yet.
It's a multi-faceted play:
It's comparing the new product to something familiar. This makes novelty and the product more relatable.
Describe a desirable solution.
He's funny. He demonstrated an iPod with an 80s phone dial in his iPhone presentation.
Then he reveals the new product. Macintosh presented itself.
Show the benefits
He outlines what Apple is doing differently after demonstrating the product.
How do you distinguish from others? The Big Breakthrough Presentation.
A few hundred slides might list all benefits.
Everyone would fall asleep. Have you ever had similar presentations?
When the brain is overloaded with knowledge, the limbic system changes to other duties, like lunch planning.
What should a speaker do? There's a classic proverb:
“Tell me and I forget, teach me and I may remember, involve me and I learn” (— Not Benjamin Franklin).
Steve Jobs showcased the product live.
Again, using ordinary scenarios to highlight the product's benefits makes it relatable.
The 2010 iPad Presentation uses this technique.
Invite the Team and Let Them Run the Presentation
CEOs spend most time outside the organization. Many companies elect to have only one presenter.
It sends the incorrect message to investors. Product presentations should always include the whole team.
Let me explain why.
Companies needing investment money frequently have shaky business strategies or no product-market fit or robust corporate structure.
Investors solely bet on a team's ability to implement ideas and make a profit.
Early team involvement helps investors understand the company's drivers. Travel costs are worthwhile.
But why for product presentations?
Presenters of varied ages, genders, social backgrounds, and skillsets are relatable. CEOs want relatable products.
Some customers may not believe a white man's message. A black woman's message may be more accepted.
Make the story relatable when you have the best product that solves people's concerns.
Best example: 1984 Macintosh presentation with development team panel.
What is the largest error people make when companies fail?
Saving money on the corporate and product presentation.
Invite your team to five partner meetings when five investors are shortlisted.
Rehearse the presentation till it's natural. Let the team speak.
Successful presentations require structure, rehearsal, and a team. Steve Jobs nailed it.