For a long time i was damn convinced that i was missing the next big thing not jumping into the bitcoin programming job market.
Reading this proved me i didn't actually miss anything and i was right to see all this as some hyper advertised meme
The book does a great job in the first 4 chapters laying the mathematical foundation for understanding cryptography more specifically Finite Fields , and Elliptic Curves. However that being said later on you realise you won't reimplement the wheel and you can be totally ignorant on how the specific algorhitms are performing hashing.
So having said that, you can see a smart contract as a assembler language , neaning that operations and variables come in as a stack which is consumed sequentially , or as a matrioska doll.
Ex:
22
33
Op_equal
hash
Put 22 on the stack , put 33 on the stack
Perform equal on these 2 values
Then hash the result
You are at all times deoendant on the blockchain and for whatever you need to perform , you make exterrnal calls to some Blockchain node to verify coins , accounts, address to send coins etc...basically everything everyone has ever done has to be stored for perpetuity somewhere...which violates the Steady State principle , the transactions have no god damn lifecycle...imagine the energy and stroage cost of this never ending , continously expanding...totally unfeasible.
Still this is in the area of Proof of Work , for your smart cotnract to do the stuff you program it to do, your Inputs>Outputs, so that there is some bitcoin fee left for the miners , the ones that lend their processing power.
Nowadays everyone jumped the Proof of Stake bandwagon when talking about crypto , meaning rhat we dont deal with blockchain anymore , with hashing and everything mathematically complex but with some dudes launching a virtual currency and hold the majority of the coins and sucking up most of the revenue generated , like the stakeholders in a typical corporation.
A filthy domain that i am glad i have not touched in my careet !
The first introductory chapters were interesting , mathematically-wise but after getting deeper you realise you could skip them and still be able to code smart contracts.
Then the mid book is a bonanza of code samples containing different methods of hashing and representing different operations when dealing with contracts (serialization, networking , parsing , etc)... The python code samples were quite cumbersome.
I for one felt the book needed more day to day examples on how to code the contracts , uniting both the business logic part with the interactions with the blockchain. However since every blockchain is different you would need to fiddle with each of them and learn their particularities... Similar to what frontend devs do whenever a [new_shit].js comes on the horizon.