
Let's build a blockchain – A mini-cryptocurrency in Ruby [video] - seoguru
https://www.youtube.com/watch?v=3aJI1ABdjQk
======
1ba9115454
This is probably the best mini implementation I've seen so far. The code is
hosted at [https://github.com/Haseeb-Qureshi/lets-build-a-
blockchain](https://github.com/Haseeb-Qureshi/lets-build-a-blockchain)

He's missed one thing though, which a lot of these small implmentations miss,
its the code for chain re-org.

[https://en.bitcoin.it/wiki/Chain_Reorganization](https://en.bitcoin.it/wiki/Chain_Reorganization)

This is a crucial piece of code that figures out which chain is correct if 1
or more blocks arrive that have a greater proof of work than your current best
chain.

But otherwise, a very good attempt.

~~~
xiphias
As far as I saw the whole blockhain is serialized and sent to the peers, so
taking care of chair reorgs is trivial (and done in the video). What's really
missing is difficulty retargeting.

------
giancarlostoro
I want to see "let's build a blockchain" minus the cryptocurrency. My
understanding was that Medical and Financial institutions were more interested
in the ledger not so much the currencies behind bitcoin and other
cryptocurrencies. Or am I looking at this all wrong?

------
jschulenklopper
Here's an earlier example I found, building a tiny blockchain in Python:
[https://hackernoon.com/learn-blockchains-by-building-
one-117...](https://hackernoon.com/learn-blockchains-by-building-
one-117428612f46).

Long, but accessible introduction. "The fastest way to learn how Blockchains
work is to build one."

------
ariza
wanna learn it

