Your childhood friend, Clay, is the biggest fan of all things related to the Blockchain technology. You've been listening to him for months and years talking non-stop about cryptocurrencies and the security of decentralized data storage.

Despite Clay's insistence on you investing in cryptos, the truth is that what you've always been interested in how the Blockchain can be applied in other applications beyond cryptocurrencies. So, as a software developer, you decide to create your own project with this technology: a to-do list API that stores all the tasks and their history of changes in Blockchain.

How it works?

This API has to allow the user to add new notes and mark them as completed. The flow will be always the same: first you need to add a new note/task and then you save it on the Blockchain. In order to make the Blockchain data persistent, we need to store the Blockchain in a file.

The Covid pandemic has forced the digitization of many sectors that were previously low-tech. Digital commerce experienced a brutal growth, but this caused some scalability and performance problems due to the high traffic that these online stores received.

For this reason, the CTO of your company has decided to implement a new type of ecommerce based on Blockchain technology on your online sales portal. The purpose is to create a network to execute and store, in a decentralized way, the different ecommerce processes.

So you will have to implement this technology in one of the most important parts of the process: the shopping cart.

How it works?

The aim of this API is to manage a shopping cart of our ecommerce website. So, through it, the Frontend Team will be able to request and create, update or delete any item in the current cart.

Every action of the API will generate a new _Block_ on the _Blockchain_ in order to create a history and persist the information, so we can retrieve it later, but also keeps a history of which items the user has added to the cart

In the last Eurovision edition (International European singing competition), the organization was the victim of a series of cyberattacks aimed at cutting off communications between countries to prevent voting.

Due to these incidents, the organization has decided to develop a new voting system to ensure security in future editions.

The organizers hired you to bring your talent and create a new voting system based on Blockchain, providing a decentralized database and ensuring the immutability of the data. It's time to give your best!

How it works?

The aim of this REST API is to add and retrieve the votes between countries and show the current state of these votes. To do so, you have to build an API that allows the countries to submit a vote to another country and also retrieve the votes submitted from all countries.

To provide a good security layer, all the countries will be attached to that Blockchain network (with a P2P network) sharing the transactions. This will give you an extra security layer against any kind of cyberattack, but also traceability of what's happening.

So, when the voting endpoint is called, the API will store the vote as a transaction and then generates a new block that will be added to the Blockchain. Finally, the node will update the Blockchain to all nodes that are connected to the P2P network.