Kian's Meditations

Talks Index

2025-04-05T15:06:47.829Z

[!tip] Youtube Channel.

File	Date
Blockchains As World Computers	Aug 31 2025
Blockchain for Beginners - Parity DOT Talk August 2025	Aug 11 2025
Polkadot Nominated Proof of Stake in AssetHub Migration (AHM) 2025	Jun 18 2025
Polkadot-SDK FRAME, But Liter -- FLITE	Jun 18 2025
Demystifying JAM - JAM Exp May 2025	May 07 2025
Polkadot Map for Builders - Polimec x Scytale Academy	May 02 2025
Blockchain for Beginners - Parity Meetup April 2025	Apr 28 2025
Demystifying JAM - PBA6	Apr 01 2025
Smart Contracts 101 - PBAX	Jan 13 2025
Podcast - Kusamarian	Jan 05 2025
Building Bridges and Ecosystems - Devcon 2024	Nov 22 2024
Polkadot-SDK FRAME @ 2024	Nov 06 2024
Demystifying JAM - Presentation	Nov 06 2024
Blockchain Scalability - A Holistic Recap	Sep 08 2024
Polkadot Blockchain Academy Hong Kong	Jun 27 2024
Nomination Pools	Aug 28 2023
Polkadot's Nominated Proof of Stake	Aug 28 2023
Phragmén for Polkadot's NPoS	Aug 28 2023
Phragmén Overview	Aug 28 2023
Introduction to Polkadot	Aug 28 2023
Substrate Debug Kit	Aug 28 2023
Random Rust Video Tutorials	Aug 28 2023

Random Rust Video Tutorials

2024-11-06T17:37:04.619Z

Introduction to Polkadot

2024-11-06T17:36:59.487Z

Smart Contracts 101 - PBAX

2025-12-12T19:06:50.259Z

Polkadot Smart Contracts

About Me

Kian Paimani aka. @kianenigma
Engineering Lead @ Parity Technologies
Polkadot Core Fellow
blog.kianenigma.com (<-- slides)

Blockchain Models

Database 🤮
A legacy of Bitcoing, and the (limited) UTXO model

Blockchain Models

State Machine ♾️
Legacy of Ethereum, and the YP.

Blockchain Models

State Machine ♾️
- State, represented as a list of key -> values
- State Transition Function

Blockchain Models

Computer 💻
Legacy of Ethereum (the "World Computer"), Polkadot JAM's Graypaper.

Note:

Database is utter BS
State Machine is accurate, but a bit to math-y
Computer is accurate, and one that most people relate to, we will use this one

The Blockchain Computer

Computer has code and storage.
Users can interact with the code (trigger a transfer 💸)
storage stores valuable information (how much money I own 🤑)
The main novelty of a computer is that it will execute code correctly, and therefore you can TRUST the storage. 🪄

The Blockchain Computer

First generation blockchains had a fixed code.
What is the code / storage of the Bitcoin computer?
- Transfer of BTC
- Is it extensible?

Note:

First blockchains were computers with a (almost) fixed code. Bitcoin's code is ONLY how to do transfer of BTC, and therefore the storage of the Bitcoin computer was only user balances. Nothing more.

The Blockchain Computer

Smart Contracts are the first step into making blockchain computers programmable.

Blockchain Computer

Ethereum is a programmable blockchain computer
What is the code of the Ethereum computer?
- Transfer of ETH
- Upload a contract
- Call into an existing contract, which might alter storage

Blockchain Computer

Execution of these contracts is as secure as the execution of the main blockchain's code. 🪄
If you can trust Ethereum and its ability to correctly transfer ETH, you should also trust that it can correctly execute whatever is the code of any smart contract.

What Is A Smart Contract

A way to add programs with custom code and storage to the blockchain computer, making it extensible, with the very same security guarantees.

Anatomy Of Smart Contracts

A Smart Contract has:

code
storage
EVM has an opinion to see contracts exactly like user accounts
- address (at which it can be invoked)
- balance: money owned by the contract

Note:
this is based on Ethereum/Solidity/EVM contracts
Bringing it all together

How to Write a Contract

Ethereum Contracts are written in a language Solidity
- Part of the Ethereum code is to execute Solidity
This happens in a virtual machine known as EVM
Solc: Solidity -> EVM Bytecode

Note:

EVM: Ethereum Virtual Machine

How to Execute a Contract

If Ethereum wants to execute a totally untrusted code, what challenges does it have?

Deterministic cost (gas)
- ⏰ Metering!
- ⛽️ gas_limit!
Deterministic output (EVM)
- 🫠 We I cannot make an HTTP request in a contract!

Extending Storage

What about the fact that a contract can add more data to its own storage, which in turn bloats the overall blockchain storage?

Storage cost needs to be taken into account
- Part of gas
- Deposit
- Storage/State Rent

Lifecycle

Case Studies

Case Study

Simple Escrow Contract

Buyer deposits funds
Both buyer and seller approve
- Transfer funds to seller
Timeout
- Return funds to buyer

Case Study

Web3 Roulette

Deposit Phase
- Anyone can deposit money into the contract
Roulette Phase
- One participants get nothing back, their money split among everyone else

Advance Topics

Composability ~ Shared Environment

VMs on a hardware
- Ethereum => Hardware
- Contracts => VMs
Synchronous and Asynchronous

Note:

Contracts on Ethereum can always call one another

Re-Entrancy Attacks

contract EtherStore {
    mapping(address => uint256) public balances;

    function deposit() {
        balances[msg.sender] += msg.value;
    }

    function withdraw() {
        uint256 bal = balances[msg.sender];
        require(bal > 0);

        (bool sent,) = msg.sender.call{value: bal}("");
        require(sent, "Failed to send Ether");

        balances[msg.sender] = 0;
    }
}

Re-Entrancy Attacks

contract Attacker {
	// Our interface to EthStore contract
    EtherStore public etherStore;

    receive() external payable {
        etherStore.withdraw();
    }
}

Checks-Effects-Interactions

Note:

Cyfrin Code Glossary: Re-entrancy Hack in Solidity

Smart Contracts in Polkadot

Polkadot

Computer who's code allows other Blockchains to be executed and validated.
Polkadot always assumed one of these external blockchains (Parachains) would deliver smart contract capability.

Past

A lot of Polkadot-based blockchains use the above tech stack

Note:

Writing smart contracts in Rust: Ink!, executed in a WASM.
Writing in Solidity, executed in EVM pallet-evm

Both of these initiated in Parity, but are pursued as community projects now.

Now

A new, much better virtual machine based on RiskV: PolkaVM

Now

Outcome: Polkadot will have fast Solidity-compatible Smart Contracts in H2 2025
Demo

Open Question

Smart Contract vs. Multi-Chain Model

Outro

Smart Contracts are the most basic form of building an application on top of a secure blockchain computer 🪄.
Battle tested approach that has been used for almost a decade now

Questions

Polkadot-SDK FRAME, But Liter -- FLITE

2025-06-18T10:18:40.431Z

FLITE is a demonstration of how Polkadot-SDK's FRAME can be utilized in a much simpler fashion, hence "FRAME lite", hence "FLITE". You can find the source code for FLITE with documentation in https://github.com/kianenigma/flite. To learn more about Polkadot-SDK and FRAME, see here.

X Post

Polkadot Nominated Proof of Stake in AssetHub Migration (AHM) 2025

2025-06-18T10:18:05.651Z

This talk explores how Polkadot's NPoS system needs to be adjusted to work on a Parachain in a multi-block and asynchronous fashion. This is part of Polkadot Hub aka. Project Plaza.

Polkadot Map for Builders - Polimec x Scytale Academy

2025-12-12T19:13:39.665Z

Polkadot Map for Builders

What Polkadot has to offer, and how to navigate it
This presentation is highly inspired by this post.
Additional resources:
- Radha's presentation, W3F Education lead
- Shawn Tabrizi's presentation, Polkadot fellow

About Me

Kian Paimani aka. @kianenigma
Engineering Lead @ Parity Technologies
Polkadot Core Fellow
blog.kianenigma.com (<-- slides)

[Polkadot Map for Builders](https://blog.kianenigma.com/talks/map-polkadot-builders/)

What is Polkadot

A multi-core, sharded blockchain that can host other Web3 applications
Extremely scalable, while not compromising on security

What Polkadot is NOT

Vertically scaling, hyper-performant, sequential blockchain

What Polkadot is NOT

Multi-chains, with sharded security (Cosmos, current Rollup landscape)

What Polkadot is NOT

Ethereum, with Native Rollups

What was (previously 😉) Polkadot

Note:

Heterogeneously sharded execution, with shared security
Embedded message passing capabilities
Mainly expressed as Polkadot Cores

What is (currently) Polkadot

Polkadot System Chains

Previously called "common good parachain"
AssetHub, BridgeHub, Coretime, People

Polkadot Statistics

DotLake Dashboard

Polkadot Statistics: Parachains

~50 active now
DeFi, Gaming, AI, RWA
Polkadot & Kusama ecosystem projects directory

Note:

Take slides from The Future of Web3 | Shawn Tabrizi

Polkadot Parachain: A Better Rollup 🤔

Cheap for Builders 🤑

Polkadot Parachain: A Better Rollup 🤔

Cheap for users

Polkadot Spammening

The Spammening

Polkadot's Resilience

Why Talking About This?

Horizontal scaling + Shared security works. It is the best, and thanks to spammening, battle tested way to scale a blockchain platform
Cheap for builders (you! 🫵🏻), ergo cheap for your users
Secure, giving you the chance to build real innovative Web3 applications

Building on Polkadot

Building on Polkadot Cores

(aka. onchain)

Parachain Development
- On-demand coretime
- Elastically scaling Parachain (1 or many cores)
Smart Contracts on Existing Parachain
Smart Contracts on Polkadot Hub
Enshrined Contract Parachain

Polkadot-SDK

![Screenshot 2025-05-04 at 10.58.32.png|400](/img/user/resources/Screenshot%202025-05-04%20at%2010.58.32.png) ![Screenshot 2025-05-04 at 10.59.21.png|400](/img/user/resources/Screenshot%202025-05-04%20at%2010.59.21.png)

Polkadot-sdk, with un-opinionated tutorials, and templates
Official documentation: docs.polkadot.com

Note:

Parachain Templates

Advanced: OpenZeppelin
DX-Friendly: POP

Smart Contracts: Solidity

Learning Solidity: We don't have to re-invent any wheels 🛞!
Targeting WASM: polkadot-evm/frontier
- Supported by Moonbeam, Acala, Astar, and many more parachains
Targeting PVM:
- Temporary Documentation, launching on Polkadot Hub in 2025

Smart Contracts: Rust / ink!

Smart Contracts: There's More

Both WASM and PVM are common compilation targets for many languages!
Example: MOVE

XCM / Messaging

All ecosystem projects:

Bridging

Polkadot <> Kusama
Polkadot <> Ethereum, fully trustless: Snowbridge
Hyperbridge
A number of bridges present on Moonbeam
✅ Reminder: within parachains, there is not need for a bridge

Coretime Purchase

Options for auto-renewal for long term teams
Coretime dashboard + Link to UIs

Offchain Applications for Polkadot

Foundational APIs

🦀 Rust: SubXT
🦖 Typescript: Polkadot JS API
🤩 Typescript: Polkadot-API aka PAPI

Note:

Light Clients

All 3 of the above are 100% light client compatible

Developers Consoles

![Screenshot 2025-05-04 at 13.52.29.png|400](/img/user/resources/Screenshot%202025-05-04%20at%2013.52.29.png) ![Screenshot 2025-05-04 at 13.53.25.png|400](/img/user/resources/Screenshot%202025-05-04%20at%2013.53.25.png)

Note:

polkadot{.js}

Mobile 📱

Curtesy of Novasama Technologies

Desktop 🖥️

Note:

Polkadot Unity SDK: Developed by Ajuna Network - YouTube
GitHub - ajuna-network/Polkadot.Unity.SDK
Site not found · GitHub Pages

The Future

Polkadot JAM -- on upgrade to radically move Polkadot towards being more open to hosting applications other than Blockchain/Smart-Contracts on itself
Everything said above will persist
Much more will be possible!

Note:

Demystifying JAM / Demystifying JAM - Presentation

Questions

The end

Demystifying JAM - PBA6

2025-12-12T19:13:20.669Z

blog.kianenigma.com/posts/tech/demystifying-jam/

Note:

This Talk

Understand what JAM is
JAM's role in the broader Web3 vision

Understanding What JAM Is

aka. Demystifying JAM

Polkadot 1

Social
- OpenGov
- DOT Token → Security
- Fellowship
Technological
- Heterogeneous Execution Sharding, with Shared Security

Note:
Sharding enabled by the use of ELVES, and heterogeneity enabled by the use of WASM.
ELVES: Efficient Execution Auditing for Blockchains under Byzantine Assumptions

Heterogeneous Execution Sharding, with Shared Security

Let's break it down:

Execution Sharding
With Shared Security
Heterogeneous

Sequential Blockchain

Note:

Opposite of execution sharding
How blockchains usually work

(Poorly) Execution Sharded

Sharding the validator set: less security

Execution Sharded with Shared Security

ELVES and Cynical Rollups
Core Model

Note:
Original vision of ETH 2 was to be this, with 64 shards.

Heterogeneous

WASM bytecode

Now You Get It?

Execution Sharding + With Shared Security + Heterogeneous

Evolution of Polkadot

... is all about flexible usage of cores

You need more to get more out of your core? Async Backing!
You need more cores? Elastic scaling!
You don't want to commit to 6m? Agile-coretime!
You need less than one core? On-demand coretime!
You want to do something other than a parachain in your core? JAM!

Path of a Parachain Block

Note:

In the existing Polkadot, the block itself is put into the DA for further auditing.

Path of a Parachain Block

Note:

Execution by core validators + made available for further auditing
State root updated by all Polkadot validators

Polkadot's Primitives

In-core execution, with access to DA
On-chain execution, with access to the main Polkadot state

Polkadot's Primitives

Polkadot currently allows you to do a limited thing in-core, and on-chain. What are they?

In-core: Re-execute the PVF, make the PoV accessible to DA
On-chain: Small signature updates

Aside: Blockspace vs. Coretime

In-core, on-chain dualism is unique to execution sharding

Note:
This is why the word blockspace, despite being wildly adopted, is not very sensible in Polkadot, because we have various modes of blockpsace. This is why the word coretime is sometimes used instead of blockspace.

JAM

Now you know everything to understand JAM.

JAM (0)

Gutting of Polkadot such that the following are directly exposed to developers.

What happens In-core
What is placed in Data Availability from the core
What happens On-chain

Note:

A parachain can only control what happens in-core. It cannot really control what happens on-chain. It also cannot readily add any data to the Data availability layer (well, it can, using remarks, which is a hack)

JAM (1)

..and removes a lot of parachain-centric opinions from Polkadot's core protocol.

JAM (2)

..and is therefore intended to be an evolution for the Polkadot Relay Chain.
Parachains, Governance, Staking, AssetHub and everything else remains intact.

Removing Opinions

JAM is programmable via a Service (PVM Bytecode)
Invocation of a service are called a Work Item
- A group of work Items are called Work Package.

Note:

In-core and On-chain

A Service is:
- fn refine(): What happens in-core
- fn accumulate(): What happens on-chain
- fn on_transfer(): Send messages to other services post accumulate
  --

Refine

Massive amounts of gas available (5s PVM)
Access to data availability
- 1.5 PB maximum size / 6s propagation time
Can receive up to 12MB of input data (from DA, or extrinsic data)
No direct access to the JAM state (stateless)
- Except preimages.
Can Invoke child PVMs

Accumulate

Direct access to the JAM state (stateful)
Less gas available (10ms PVM)
Fully synchronous: Access the refine results of all other services, from possibly all other cores at once.

JAM (Recap)

Allowing Services to program exactly how they want to use:

In-core execution
On-chain execution
Data availability

Path of a JAM Work Package

JAM

PVM

Metered (benchmarking 🤢)
Very fast (45% native)
PVM instance can invoke another instance
- Service can invoke a parachain, or smart contract, or anything else
Easy to pause and resume -> Continuation

JAM Misc

JAM offers a similar bulk coretime purchase model to that of Polkadot
- No per-transaction purchase
- Much greater economic freedom for services/applications!

JAM Misc (1)

JAM offers a much more flexible Authorization mechanism for core utilization
- authorize() -> refine() -> accumulate() -> on_transfer()

JAM Envisioned Services

CoreChains
CoreVM / CoreBoot / JAMDocker
CorePlay

`CoreChains`

Entire Polkadot 2 + Parachains is one service

Note: This is an example of JAM's low abstraction level

`CoreVM`

Running normal applications on JAM
Demonstration of PVM's "continuation"
Utilizes DA to store intermediate program state, such as the stack and registers
🎯 DOOM!

`CorePlay`

Ultimate actor based smart contract platform
Non-persistent state partitioning

Note: This is a prime example of JAM's transient decoherence in action

`CorePlay`

JAM Introduction Ends

Questions?

The Web3 Vision and JAM

Abstract look at blockchain/Web3 technology

Blockchain Mental Models

🤮 Database
♾️ State Machine
💻Computer

Blockchain Mental Models

A computer has two main primitives
- ⚙️ Computation
- 💿 Storage

Generic Blockchain Computer

A blockchain/Web3 computer has:
- ⚙️ + 👮‍♂️ Secure computation
  - Canonical ordering + auditability of the said secure computation
- Secure, public-by-default storage
  --

Sequential, Non-Sharded Blockchain Computer

Limited + Expensive computation
Limited + Expensive storage
Fully coherent environment, albeit kinda useless

Sharded Blockchain Computer

Abundant computation
Abundant storage
- Limited + Expensive coherent L1 storage
- Abundant incoherent rollup storage
Fully incoherent environment, which still makes it kinda useless
Multi-core CPU, without any shared memory!

Note:

This model is potentially useful, if you want a lot of throughput, high customization, and don't care much about interoperability

JAM: Supercomputer

Multi-core CPU with shared memory!
JAM is a supercomputer. It is most performant Web3 computer one can build, without sacrificing security

JAM: Supercomputer

Abundant secure computation (ELVES)
Abundant storage
- Limited coherent L1 storage (JAM State)
- Abundant, mostly coherent DA storage ( $D^{3} L$ )
- Fully incoherent service storage

JAM: Web3 Cloud

JAM is like supercomputer that takes the has the most high quality primitives of the Web3 computer, and exposes them all to developers
JAM is the (virtual) Web3 hardware on top of which we can build what we may dare call Web3 Cloud.

Questions

Appendix / Backup Slides

Kernel Update Analogy

Note:

Hardware is what provides compute and bandwidth, and the kernel is part of the OS that moderates the hardware access.
Current Polkadot. A lot of stuff is part of the "Kernel/OS".

Work Item

graph LR 
	subgraph WorkPackage 
		WI1[Work Item 1]
		WI2[Work Item 2]
		WI3[Work Item 3]
	end
	subgraph WorkReport
		WR1[Work Result 1]
		WR2[Work Result 2]
		WR3[Work Result 3]
	end
	
	WI1 --> WR1
	WI2 --> WR2
	WI3 --> WR3