Introduction to Substrate

AlephZero: Custom consensus, DAG-based, 1s block time.
Moonbeam: Ethereum compatible, build with substrate.
HydraDX: Custom transaction pool logic to match DEX orders.
Kulupu: Proof of work, custom hashing.

What is Substrate?

Substrate is a Rust framework for building blockchains in a modular and extensible way.

Example: SCALE vs JSON

use parity_scale_codec::{Encode};

#[derive(Encode)]
struct Example {
    number: u8,
    is_cool: bool,
    optional: Option<u32>,
}

fn main() {
    let my_struct = Example {
        number: 42,
        is_cool: true,
        optional: Some(69),
    };
    println!("{:?}", my_struct.encode());
    // [42, 1, 1, 69, 0, 0, 0]
    println!("{:?}", my_struct.encode().len());
    // 7
}

Example: SCALE vs JSON

use serde::{Serialize};

#[derive(Serialize)]
struct Example {
    number: u8,
    is_cool: bool,
    optional: Option<u32>,
}

fn main() {
    let my_struct = Example {
        number: 42,
        is_cool: true,
        optional: Some(69),
    };
    println!("{:?}", serde_json::to_string(&my_struct).unwrap());
    // "{\"number\":42,\"is_cool\":true,\"optional\":69}"
    println!("{:?}", serde_json::to_string(&my_struct).unwrap().len());
    // 42
}