The Blockchain (distributed ledger technology)



DAO Hack with Matt Leising

The Decentralized Autonomous Organization (DAO) was a digital form of venture capital. It was an ambitious idea–to provide a new decentralized business model for organizing corporations on top of the Ethereum blockchain. Few people in the crypto community were opposed to this premise–but the timeline was short, the code requirements were tremendous, and in retrospect, a vulnerability was inevitable.

The DAO launched in May 2016, setting the record for the largest crowdfunding event in history. The following month, the DAO was hacked, millions of dollars of Ether were stolen, and the reverberations of the event were a referendum on how the Ethereum community governs itself.

Matt Leising is a reporter for Bloomberg who has chronicled the DAO in his article The Ether Thief. He continues to follow cryptocurrencies closely, as the Internet of money fractals increasingly into the public consciousness.




I’m not trying to reviving that topic :stuck_out_tongue: is just another blockchain initial implementation in Elixir


Well, I guess this is a topic that deserve a resurrection once in a while :lol:


More then a resurrection it diserves a implementation, Solidity sucks! Anybody doing something for real?


For real is Ethereum :slight_smile:


I was thinking there is only Ethereum, but this one looks interesting, and even written in Eralng.

A parallel internet inside the first truly scalable cryptocurrency.




Its happening …


Hello all, just tried searching thru the forums for ICO (initial coin offerings) but couldn’t find anything so figured this would be the most appropriate place to post this. For those of you not familiar with ICOs, they’re a LITTLE similar to an IPO (initial public offering) but instead of stocks, it’s the coins a company sells.

Why is this relevant to you?

Because I attended a seminar last night in San Francisco where a respected VC and crypto investor emphasized that an ideal ICO would be an open source project where the majority of the tokens would be allocated FOR THE DEVELOPERS to INCENTIVIZE us to contribute to the ecosystem.

For those of you looking for high paying salaries, let me put it to you in perspective. If a company suddenly just got millions of dollars AND HAVE TO ALLOCATE THAT TO DEVELOPERS, they’d be a much better target than a small company operating on a tight budget or even a startup who got venture capital (typically less than what an ICO will provide)

The part I’m still trying to figure out for myself (both from an employer or employee perspective) is how would Elixir best be utilized with Blockchain because isn’t it written in C/C++ and Ethereum in Go?

Any thoughts or opinions greatly welcomed.

I’ll attach some screenshots as well.


Enterprise Smart Contracts with Marley Gray

In this episode, Marley Gray from Microsoft joins the show to discuss enterprise smart contracts–why you would want to use them and how they can be architected. Marley has worked on banking and financial technology for over a decade, and makes some strong arguments for why banks will adopt smart contracts, and the timeline for how that might take place.


I thought this episode was particularly interesting when Marley talked about how an enterprise integration might occur between businesses using a shared ledger.

When doing something a stateless integration probably with REST, you can often end up coupling systems together through some variation of schema(probably JSON). You have types, often nested associations, and field names that each system needs to support. If you need real-time coordination between these information systems such as when a contracting company is fulfilling some services for a shared customer, having a stateless API doesn’t fit the bill very well. Both systems probably have very different implementations in place, and the complexity of polling, authentication, authorization, and handling record changes can get pretty complex when you’re dealing with database conflicts and reactive logic to said changes.

A good description of some of the challenges involved with using this sort of API in Elixir/Ecto might be Dennis Beatty’s recent talk at Lonestar. The gist of it is Podium is polling a Google REST API for Reviews, and processing changes for updates, handling conflicts etc. You end up running into some troublesome limitations with Postgres sequencing and what-not dealing with these upserts and conflicts.

The obvious alternative solution might be a messaging, pub-sub type integration where the two systems are coupled by a set of ubiquitous events that can then be handled by either system as needed. This could be done with a central server (Elixir/Erlang is a great fit) that runs some handshaking for authentication, sets up channels, and delivers encrypted events to the subscribers.

The problem with doing it this way is dependency on this central service. Which company is running this middle-man event-messaging service? What if there’s a conflict? What if one party distrusts the message being sent from this service? This is where having a distributed ledger becomes interesting. Both companies can host a node of this middle-ware service and maintain a copy of the ledger of the events. Now there’s no centralized dependency on a service hosted by either party, the same (potentially event-sourced) capabilities are supported.

Instead of the Google Reviews API requiring polling of stateless resources, you throw up a Node, download the ledger, and consume events into whatever architecture you prefer. You get an audit-able, event-sourced, Kafka-esque functionality between multiple parties that doesn’t have the same technical problems as stateless API integrations.

Anyone know similar systems being built like this? I find these patterns really interesting.


Great write up! Thanks for sharing that.

I did find this excellent list of use-cases for blockchain technology over at Hyperledger:

Just one of the use-cases:

The more integrated is a health care delivery system, the less advantage there is to maintaining a provider directory in a blockchain. Conversely, as the relationship between the system and the providers becomes more fluid, the more compelling it is to implement both a consumer facing and a provider facing directory as a blockchain.

I’d consider that list and those related pages great sources of inspiration for anyone getting into blockchain development.

I also found the Golem blockchain platform (, which was used to render CGI:

Golem also has a monetary aspect in terms of their software marketplace, and seems they are putting software developers at the helm. Current market cap at $350m:


IBM is using Hyperledger as far I know. You can check theirs twit


Is there an ongoing project that is related to this?


@rickmutua Ethereum has dedicated project in Elixir


whats the name of the project?


This is the link to the project


Be aware that that project (while probably great!), is not maintained by the Ethereum Foundation: It’s not hosted under the ‘Ethereum’ organization on GitHub, but under the ‘Exthereum’ organization.