# 👋 Hi, I'm Yos.

### I'm a Software Engineer based in Singapore.

Here are some recent articles...

Cryptocollectibles are rapidly becoming one of the earliest mainstream use cases of the blockchain. Let’s examine how the blockchain is changing how we view art.

The ERC20 token standard has achieved near-complete industry adoption. It defined six minimal requirements for the way tokens behave on the Ethereum blockchain. Anyone could comply with the token standard and implement additional functions as needed. This standard ignited the ICO wave, allowing for the creation of core infrastructure and exchanges that is the backbone of the crypto ecosystem today.

Let’s look at Ethereum ERC standards you should know about - including some you’ve never seen before!

Relying on meme magic and hype to support a token value is a shaky foundation. While attractive because of its ability to raise capital, these tokens will find themselves at risk of collapse when the market turns.

For a token to have a stable value, it needs token sinks - places where tokens can be ‘spent’ so the total circulating supply decreases over time. In this article, we’ll examine several real-life token projects and how they make their tokens spendable. We’ll look at three token models: Protocol Tokens, Platform Tokens, and Governance Tokens.

Harberger Taxes is an economic abstraction that aims to democratize the control of assets between private and commons ownership. In this taxation system, asset owners self-assess the value of assets they own and pay a tax rate of X% on that value. Whatever value owners specify for the asset, they have to be willing to part ways and sell it to anyone at that price.

💡 Harberger Taxes was repopularized by its mention in Radical Markets.

The emerging field of cryptoeconomics uses both cryptography and economic incentives to design decentralized protocols and applications. Smart contracts defines the rules of an economic game which incentivize rational actors to behave in optimally desirable ways. Decentralized protocols lets us inscribe transparent rules on the blockchain that aligns individual incentives to achieve a common goal.

Previously, it was difficult or even impossible for economists to test these ideas in a real environment. Blockchains offer a testing ground for economic abstractions such as Harberger Taxes, where rules can be enforced with smart contracts.

Let’s examine the Harberger Tax model and discover how we can use it in decentralized applications.

An Ethereum transaction needs to be included in a block and mined before it is processed and saved on the blockchain. As a result, on-chain transactions takes time and costs gas to compensate miners for their work.

In contrast, off-chain computation lets you perform actions instantly without waiting for transactions to be mined and does not cost any gas.

In this article, let’s look at how you can perform off-chain computation using Ethereum signatures. Cryptographic signatures can be used to validate the origin and integrity of messages. Then, we’ll examine real-life use cases of off-chain computation such as decentralized exchanges, state channels, and meta transactions.

“Show me the incentive and I will show you the outcome.” – Charlie Munger

The token bonding curve is an emerging cryptoeconomic primitive: protocol based incentive systems that enable coordination of network participants to achieve shared goals. Tokens incentivize players in an economic game towards an outcome that are mutually beneficial.

In this article, let’s take a look at what bonding curves are and its use cases. Along the way, we’ll learn about automated market makers and and continuous organizations - potential applications of bonding curves.

A crypto token that passes the Howey Test is deemed a Security token. Security tokens are designed to represent complete or fractional ownership in an asset. While utility tokens have no limitations on who can send or receive the token, security tokens are subject to many restrictions based on identity and jurisdiction.

In the same way that the ERC-0 token standard helped to create a boom in utility tokens, a security token standard will help drive the adoption of security tokens.

In this article, let’s look at the current state of security token standards in the Ethereum ecosystem and each of their approaches to build a self-regulatory governance mechanism for these tokens.

Web applications today are built iteratively. With continuous delivery, developers release hotfixes and new features hundreds of times a day. We upgrade our software all the time with little ceremony.

Upgradability is something that you don’t truly appreciate - until you’ve written smart contracts. Why? Because smart contracts are immutable - it’s not possible to upgrade the source code of an already deployed contract. In this aspect, developing smart contracts is closer to hardware programming than web development.

At the same time, decentralized applications and smart contracts are a new and highly experimental space. There are constant changes in the security landscape and the cost of failure are in the high tens or hundreds of millions of dollars. Code will need to be changed if errors are discovered or if improvements need to be made. It is no good to discover a bug, but have no way to deal with it.

As software engineers, we seek to build software systems that is modular and supports upgradable components. To handle the large space of smart contract attack vectors, we need a mechanism through which we can safely and securely upgrade our smart contracts. This is especially true when you build complex, perpetual contract systems instead of one-time token sale contracts.

In traditional software development, security vulnerabilities can be fixed by patching. When there’s a bug in your system, you can write a fix, deploy it, and prevent future exploits of that specific bug. Patches are frequent and easy.

Patching security vulnerabilities of decentralized applications on the Ethereum blockchain is not so straightforward. Due to the immutable nature of smart contracts, it’s difficult (and sometimes impossible) to upgrade already deployed contracts.

On the other hand, the potential losses of smart contract hacks can be exorbitant, with losses of more than US$70M for the DAO Hack and US$200M for the 2nd Parity Hack. Considering both the difficulty of upgrading contracts and high exploit risk, smart contract developers need to be vigilant and apply defensive programming techniques when designing smart contracts to prevent vulnerabilities in the initial design.

In this article, let’s look at common security vulnerabilities in Solidity smart contracts and how to mitigate them.

Learn about the most popular projects and product offerings in the Serverless ecosystem today! (Last updated 19 June 2018.)

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Have you heard about the Serverless programming model? The Going Serverless book teaches you how to build scalable applications with the Serverless framework and AWS Lambda. You'll learn how to design, develop, test, deploy, and secure Serverless applications from planning to production.