</> Cosmin Marica

    Web3 / Blockchain Engineering

    Solidity + Backend + Full-Stack Delivery for EVM Products

    I build Web3 systems that are production-oriented: smart contract architecture, event indexing, wallet integration, governance flows, and backend services that keep on-chain and off-chain data aligned.

    Web3 Skills

    Smart Contract Engineering

    Solidity
    Hardhat
    Contract modularization
    Access control patterns
    Upgradeable design choices
    Test-driven contract delivery

    Token Standards & EVM

    ERC-20
    ERC-721
    ERC-1155
    ERC-2981
    EVM-compatible chains
    Gas-conscious architecture

    On-Chain Data & Indexing

    Event indexing pipelines
    WebSocket listeners
    Chain reorg-safe persistence
    On-chain/off-chain data sync
    PostgreSQL-backed analytics
    Backend reconciliation logic

    Wallet, Governance & Product Integration

    Wallet integrations
    viem and wagmi
    Governance proposal flows
    Oracle-based logic
    Frontend/backend coordination
    Production dApp UX

    Selected Web3 Projects

    DECA

    Token ecosystem platform with ICO, vesting, staking, wallet-based flows, and on-chain/off-chain service coordination.

    Solidity
    ERC-20
    Node.js
    PostgreSQL
    WebSockets
    viem
    Hardhat

    Engineering focus

    • Built and tested smart contracts for token sale, vesting, and staking logic.
    • Implemented backend event indexing to keep dashboards synchronized with chain state.
    • Integrated wallet flows and external services without sacrificing product reliability.
    Live

    BlockEstate

    Fractional real-estate governance dApp with ERC-1155 ownership shares, proposal flows, and exit-round mechanics.

    Solidity
    ERC-1155
    Governance
    Node.js
    PostgreSQL
    wagmi
    viem

    Engineering focus

    • Designed contract architecture for governance actions and asset lifecycle control.
    • Built event-driven indexing services to mirror governance and ownership changes off-chain.
    • Connected wallet UX with backend systems for fast product-level views and actions.
    Code

    Eternal Warriors

    NFT game architecture combining on-chain asset logic and off-chain gameplay services for responsive user experience.

    Solidity
    ERC-721
    Node.js
    React
    Hardhat
    EVM chains

    Engineering focus

    • Implemented NFT progression and gameplay-linked contract interactions.
    • Designed backend services to sync chain events with game state and player data.
    • Balanced secure contract logic with real-time gameplay performance requirements.
    Code Smart Contract Code

    Professional Experience

    Web3 Developer (Solidity + Backend + Full-Stack)

    2022 - Present

    Building production-oriented Web3 systems across smart contracts, event indexing, wallet integrations, and full-stack product delivery on EVM-compatible chains.

    How I Work

    01

    Define protocol and product boundaries early to avoid fragile contract assumptions.

    02

    Model on-chain/off-chain sync explicitly with event-driven backend services.

    03

    Implement wallet and governance flows with predictable UX and fallback handling.

    04

    Ship incrementally with tests, verification steps, and practical collaboration rhythm.

    Building a Web3 Product That Needs Execution Depth?

    I work with blockchain startups and crypto product teams that need practical Solidity engineering combined with dependable backend and full-stack implementation.

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