My Blockchain Master's: 8 Projects That Transformed My Career

🎯 Executive Summary

With nearly 20 years of software engineering experience, I decided to make a radical shift: master the Blockchain and Web3 ecosystem from scratch. The result: 8 open-source projects ranging from online stores with their own currency to programming inside the Linux kernel. This article is the technical retrospective of that journey, with links to the source code of each project.

A Year Building in Web3

The Blockchain and Web3 Master from CodeCrypto Academy was an intense year of practical projects that covered the complete stack of the decentralized ecosystem: from Solidity smart contracts to Linux kernel programming with eBPF.

This is the retrospective of the most important projects I developed during the master program.

🗺️ The Learning Track

The master followed a logical progression, from foundations to the full stack:

flowchart LR
    A[Ethereum Basics] --> B[Solidity]
    B --> C[Foundry]
    C --> D[Full-Stack Web3]
    D --> E[DeFi / Stablecoins]
    E --> F[DAOs / Governance]
    F --> G[Rust]
    G --> H[REST API]
    H --> I[eBPF / Linux Kernel]
    
    style A fill:#1a1a2e,stroke:#00f2ff,stroke-width:2px,color:#fff
    style I fill:#1a1a2e,stroke:#00ff88,stroke-width:2px,color:#fff

Each phase built upon the previous one, creating a solid foundation that allowed tackling increasingly complex projects.

🚀 The Projects

1️⃣ 🔗 SupplyChainTracker2

First full-stack Web3 project. Traceability of educational devices (netbooks) on the EVM blockchain with RBAC access control, Foundry, and Wagmi.

The problem it solves: A school needs to track the distribution and location of netbooks to students, ensuring the registry is immutable and auditable.

Stack: Solidity · Foundry · React · Wagmi v2 · Anvil

Key repository files:

• contracts/SupplyChainTracker.sol - Main contract with traceability and RBAC logic
• test/SupplyChainTracker.t.sol - Exhaustive tests with Foundry
• frontend/src/ - React interface with Wagmi for on-chain interaction

2️⃣ 📄 DocumentSignStorage

Decentralized notarial registry. Allows signing and registering the existence of any document using Keccak-256 hash and EIP-712 signatures, without uploading the file to the blockchain.

The problem it solves: How to prove a document existed on a certain date without exposing its content? The solution uses cryptography to register only the "fingerprint" of the document.

flowchart LR
    A[Original Document] --> B[Keccak-256 Hash]
    B --> C[EIP-712 Signature]
    C --> D[On-Chain Transaction]
    D --> E[Immutable Registry]
    
    F[Verification] --> G[Calculate Hash]
    G --> H{Matches?}
    H -->|Yes| I[✅ Valid Document]
    H -->|No| J[❌ Modified Document]
    
    style A fill:#1a1a2e,stroke:#00f2ff,stroke-width:2px,color:#fff
    style E fill:#1a1a2e,stroke:#00ff88,stroke-width:2px,color:#fff
    style I fill:#1a1a2e,stroke:#00ff88,stroke-width:2px,color:#fff
    style J fill:#1a1a2e,stroke:#ff0066,stroke-width:2px,color:#fff

Stack: Solidity · EIP-712 · Foundry · Next.js 16 · Ethers.js v6

Key repository files:

• contracts/DocumentSignStorage.sol - Registry contract with EIP-712 signatures
• web/app/ - Next.js frontend for signing and verification

3️⃣ 🛒 Euro-Ecommerce

Decentralized e-commerce with a custom stablecoin. Complete ecosystem with EURT token (ERC-20, 6 decimals), Stripe fiat on-ramp, modular contracts, and customer and admin dApps.

The problem it solves: Integrating traditional payments (credit cards) with blockchain. The user pays with Stripe and receives EURT tokens to shop on-chain.

graph TB
    subgraph Smart Contracts
        SC[sc-ecommerce]
        ST[stablecoin/sc/EURT.sol]
    end
    subgraph Web Apps
        WC[web-customer]
        WA[web-admin]
    end
    subgraph External Services
        S[Stripe Payments]
    end
    
    S -->|Fiat On-ramp| WC
    WC -->|Buy EURT| ST
    WC -->|Shopping Cart| SC
    WA -->|Management| SC
    
    style SC fill:#1a1a2e,stroke:#00f2ff,stroke-width:2px,color:#fff
    style ST fill:#1a1a2e,stroke:#00ff88,stroke-width:2px,color:#fff
    style S fill:#1a1a2e,stroke:#ff00f2,stroke-width:2px,color:#fff

Stack: Solidity · ERC-20 · Stripe · Next.js · Wagmi

Key repository files:

• stablecoin/sc/EURT.sol - ERC-20 token with 6 decimals (Euro cents)
• sc-ecommerce/contracts/ - Modular store contracts
• web-customer/ - Buyer dApp
• web-admin/ - Admin dashboard

4️⃣ 🏛️ DAO Governance System

Gasless governance. Decentralized voting system with meta-transactions (EIP-712 + ERC-2771) and an internal Relayer that pays gas on behalf of the voter.

The problem it solves: In a traditional DAO, every vote costs gas in ETH. This excludes participants without funds. With meta-transactions, the user signs for free and an intermediary server pays the gas.

sequenceDiagram
    participant U as User
    participant W as Wallet
    participant R as Relayer API
    participant C as DAO Contract
    
    U->>W: Sign vote EIP-712 (free)
    W-->>U: Returns Signature
    U->>R: POST /api/relay {signature}
    R->>C: executeMetaTx(signature)
    C-->>R: Vote registered on-chain
    R-->>U: 200 OK {txHash}
    
    note over U,C: The user never pays gas

Stack: Solidity · ERC-2771 · Foundry · Next.js · Wagmi · Viem · TanStack Query

Key repository files:

• contracts/GovernanceToken.sol - ERC-20 token with vote delegation
• contracts/GovernorDAO.sol - Proposal logic and lifecycle
• contracts/Forwarder.sol - ERC-2771 implementation for meta-transactions
• packages/web/src/ - Next.js frontend with real-time dashboard

5️⃣ 🦀 Northwind with Rust/Rocket

REST API in Rust. Full-stack case study with the Rocket framework and SQLx (compile-time validated queries) connected to MariaDB.

The problem it solves: SQL queries in web applications are a common source of bugs. With SQLx, the Rust compiler validates that queries exist in the database before compiling.

Stack: Rust · Rocket 0.5 · SQLx · MariaDB · Next.js

Key repository files:

• src/ - Rust code with Rocket and SQLx
• migrations/ - Database migrations

6️⃣ ⚡ eBPF Blockchain Node

The most experimental project. A P2P node that uses eBPF with XDP (eXpress Data Path) to intercept and process network packets at the Linux kernel level, implemented in Rust with the Aya framework.

The problem it solves: Is it possible to run blockchain logic directly in the kernel? This experiment proves it is, by intercepting network packets before they reach the traditional IP stack.

flowchart TD
    NIC[📡 Network Interface Card] --> XDP[⚡ XDP Hook]
    XDP -->|eBPF Program| K[🔧 Kernel Space]
    K -->|Aya Maps| U[💻 User Space]
    U -->|Rust App| P2P[🌐 P2P Node Logic]
    P2P -->|Broadcast| NIC
    
    subgraph Kernel
        XDP
        K
    end
    subgraph User Space
        U
        P2P
    end
    
    style NIC fill:#1a1a2e,stroke:#00f2ff,stroke-width:2px,color:#fff
    style XDP fill:#1a1a2e,stroke:#ff00f2,stroke-width:2px,color:#fff
    style P2P fill:#1a1a2e,stroke:#00ff88,stroke-width:2px,color:#fff

Stack: Rust · eBPF · Aya · XDP · LXC · Linux Kernel

Key repository files:

• rust/ebpf-node/src/ - eBPF program compiled for kernel
• ansible/ - Ansible playbooks for automated deployment
• monitoring/ - Prometheus + Grafana for observability

📊 Technologies Mastered

During the master I dived deep into this entire ecosystem:

🧠 What Impacted Me the Most

If I had to choose the three most valuable learnings from the year:

1. Rust's borrow checker teaches you to think in ownership

It's frustrating at first, but the errors it prevents are real production bugs. Data races, use-after-free, double-free: the compiler catches them before they exist.

2. State in blockchain is radically different

There are no "free" transaction rollbacks, everything has a gas cost, and asynchronous synchronization with the UI requires specific patterns like optimistic updates and retry logic.

3. eBPF democratizes the kernel

Being able to program the Linux kernel with Rust without writing a module is a paradigm shift. The possibilities for observability, security, and networking are enormous.

🔮 Next Steps

The ecosystem that calls me the most going forward is Solana: its parallel account architecture (Sealevel), the use of Rust as the native language for smart contracts (programs), and the throughput approaching 50,000 TPS make it technically very interesting.

I also want to deepen my use of LXC + eBPF to build high-performance network monitoring systems in on-premise Linux environments.

🔗 All Repositories

Retrospective of the Blockchain and Web3 Master — CodeCrypto Academy 2025-2026