Hợp đồng thông minh Jobs

I’m commissioning a full smart-contract build, from architecture through main-net deployment. The application layer itself is still open-ended, so you’re free to recommend the most suitable chain—Ethereum, BNB Smart Chain, Solana or another EVM-compatible network—provided it meets typical requirements for security, scalability, and broad wallet support. Here’s what the engagement looks like: • Scope: write Solidity (or comparable) contracts, implement upgradeability if justified, optimise gas, and document each function clearly. • Quality: unit tests in Hardhat/Foundry or Truffle with ≥90 % coverage, plus a static-analysis report (Slither, MythX, or similar) to verify there are no critical vulnerabilities. • Deployment: scripts for ...

Our new platform, CritiQ, needs a suite of robust, reusable smart contracts. I already have the product vision, tokenomics draft, and high-level user flows; now I’m ready to turn that vision into audited code. Here’s what I expect from this engagement: • Architecture & specification – refine requirements with me and translate them into a concise technical spec. • Development – implement the contracts in Solidity using best-practice libraries such as OpenZeppelin, with comprehensive unit tests in Hardhat or Truffle. • Security & gas optimisation – apply industry-standard patterns, write clear modifiers, and run automated analysis (Slither, MythX, or similar) before handing the code over for an external audit. • Deployment &am...

I'm looking for an experienced developer to create a Web 3 video chat application for desktop. The platform should integrate multiple Web 3 technologies, including: - Blockchain - Cryptocurrency - Decentralized storage - Smart contracts - Video infrastructure Essential Features: - Secure login/authentication - End-to-end encryption Ideal Skills and Experience: - Proficiency in blockchain technology - Experience with cryptocurrency integration - Knowledge of decentralized storage solutions - Strong background in smart contracts - Expertise in video chat infrastructure development - Strong security practices in app development Please provide a portfolio showcasing similar projects.

Socifi, our real-time Texas Hold’em poker web app, already has the core game loop, React lobby and table UI, and working game logic. The missing piece is a solid back end that persists data and ties everything together. What needs doing right away • Re-enable and wire up MongoDB so user profiles, game states (hands, pots, blinds, results), and transaction/payment records are stored, queried, and indexed efficiently. • Patch the current authentication flow so sign-up, login, and token refresh are reliable across reconnects and multiple tabs. • Activate or complete the half-finished features in the existing codebase (e.g., player avatars, hand history modal, chip top-up) and remove unused remnants. • Prepare environment variables, seeding scripts, and pr...

Im looking to create my own cryptocurrency on the solana blockchain. 5 minutes work 1 billion coins. As low price as possible. 0.000000001$ select all coins - transaction fees on/earn by transactions on. select all coins and release all coins

Im looking to create my own cryptocurrency on the solana blockchain. 5 minutes work 1 billion coins. As low price as possible. 0.000000001$ select all coins - transaction fees on/earn by transactions on. select all coins and release all coins

1.-PROJECT TITLE (Short & Professional) Development of a Blockchain-Based Decentralized Authentication Prototype Integrated with SQL Server 2.-BULLET POINT VERSION (If it asks for key points) You can paste this in the bullet/summary section: Academic research prototype (not a full hospital system) Decentralized authentication using blockchain (smart contract) Integration with Microsoft SQL Server Medical records stored in SQL Server (not on blockchain) Blockchain used for authentication hash validation Architecture documentation required Basic performance observation (authentication response time) Conceptual alignment with GDPR and HIPAA (no legal certification required) Full source code and technical explanation required 3.-FULL DESCRIPTION (Complete Version to Post) Hel...

I have a nearly finished cryptocurrency payment gateway that lets online merchants accept TEXITcoin (TXC) and PUREmedal (PURE). The core smart-contract logic, checkout flow and database schema are already in place, and the stack is React on the front end with a Node.js back end. What I need now is an experienced full-stack Web3 developer who can tie up the loose ends, harden the code and get us to a production launch. Key gaps to close • Merchant dashboard polish – merchants must be able to generate API keys, configure webhooks, and choose between HD/xpub or static wallet addresses. • Checkout edge cases – customers see a payment address and live status updates; the status must stay accurate even on slow or re-orged blocks. • Reliable notifications –...

Product Overview P2P Crypto Marketplace for Digital Goods A decentralized, escrow-backed peer-to-peer marketplace enabling users to safely trade digital goods (subscriptions, gift cards, licenses, accounts) using cryptocurrency, launched as a Telegram Mini App for instant global reach. The platform eliminates trust issues in digital goods trading by combining KYC verification, smart-contract escrow, and multi-step trade validation. Core Value Proposition Trade digital goods globally with crypto—without trust, fraud, or delays. No chargebacks No middleman holding funds No long onboarding Built for crypto users, not adapted for them How It Works (Trade Flow) User Verification Telegram login (one-tap) Mandatory KYC (basic → advanced tiers) Wallet connection (EVM-comp...

I’m ready to launch my own BEP-20 token on Binance Smart Chain and need a developer who can handle the full smart-contract build and deployment. The token must follow the standard BEP-20 specification and include a Minting function so I can expand the supply later when needed. Here’s what I expect from you: • Write a clean, well-commented Solidity contract (OpenZeppelin libraries preferred). • Configure minting so only the owner (my wallet) can call the function. • Deploy the contract to testnet first, then mainnet once I have verified everything. • Verify the source code on BscScan and hand over ownership. • Supply all source files plus a short read-me explaining contract variables, how to mint, and any safety considerations. I already have...

I’m planning to launch a new blockchain-based product and I need an experienced developer who can guide me from concept to main-net deployment. At this stage I’m flexible about the exact stack—Ethereum, Binance Smart Chain, Solana or another network—so I value someone who can weigh the trade-offs and recommend the best fit for scalability, fees, security, and time-to-market. The broad vision includes designing the core smart contracts, creating a native token, integrating a secure wallet flow, and building out any web or mobile front-end required for users to interact with the chain. I also want clear documentation and the test coverage needed for a smooth audit. Deliverables I’d like to see: • Technical roadmap outlining the chosen architecture, toolin...

Product Overview P2P Crypto Marketplace for Digital Goods A decentralized, escrow-backed peer-to-peer marketplace enabling users to safely trade digital goods (subscriptions, gift cards, licenses, accounts) using cryptocurrency, launched as a Telegram Mini App for instant global reach. The platform eliminates trust issues in digital goods trading by combining KYC verification, smart-contract escrow, and multi-step trade validation. Core Value Proposition Trade digital goods globally with crypto—without trust, fraud, or delays. No chargebacks No middleman holding funds No long onboarding Built for crypto users, not adapted for them How It Works (Trade Flow) User Verification Telegram login (one-tap) Mandatory KYC (basic → advanced tiers) Wallet connection (EVM-comp...

I’m ready to launch my own BEP-20 token on Binance Smart Chain and need a developer who can handle the full smart-contract build and deployment. The token must follow the standard BEP-20 specification and include a Minting function so I can expand the supply later when needed. Here’s what I expect from you: • Write a clean, well-commented Solidity contract (OpenZeppelin libraries preferred). • Configure minting so only the owner (my wallet) can call the function. • Deploy the contract to testnet first, then mainnet once I have verified everything. • Verify the source code on BscScan and hand over ownership. • Supply all source files plus a short read-me explaining contract variables, how to mint, and any safety considerations. I already have...

Hi I will share the details with the shortlisted candidates. Thanks

Hi I will share the details with the shortlisted candidates. Thanks

I already have a draft smart contract, but it needs a careful review and a few modifications before going live. Once the code is solid, I want it deployed on Ethereum (that is my first choice, though I’m open to discussing BSC or Polygon if you feel they offer clear advantages). After deployment, the contract must be fully integrated into my website so users can interact with it through MetaMask. A smooth, reliable Web3 flow is essential—wallet connection, transaction signing, on-chain confirmations, and any UI feedback should feel seamless and secure. The job breaks down into three main parts: • Audit, adjust, and finalise the existing contract code, then compile, test, and verify it on the chosen network. • Deploy the verified contract and wire it up to the s...

Position: Freelance Smart Contract / Blockchain Engineer Type: Contract / Freelance Location: 100% Remote Workload: Part-time or task-based Compensation: $60–$100/hour (or fixed-price per task) About the Project We are working on DeFi smart contract components, including token implementations and protocol-level logic. Our focus is security, clarity, and real-world usability — not hype. We are building a long-term freelancer pool and looking for engineers who can deliver clean, well-structured Solidity code independently. What You’ll Do Design and implement secure smart contracts using Solidity Work with EVM-compatible chains Review and improve existing smart contract code Follow best practices for documentation, testing, and security Collaborate asynchronously wi...

Need a Solidity dev for a simple MVP: team-based NFT positions + monthly oracle update + reward claim. Contracts only (no frontend). Stack: Solidity + OpenZeppelin + Foundry. Must include tests, deployment script, and clean documentation.

I need a brand-new ERC-20 smart contract built from scratch, then deployed to the Ethereum network. The token must include minting, burning, and pausable functionality, implemented with clean, upgrade-friendly Solidity code that follows current best practices (OpenZeppelin libraries, Hardhat or Foundry for testing). Please create, test, and deploy the contract, then hand over everything required for future maintenance. Deliverables • Verified Solidity source code with mint, burn, and pause modules • Full test suite covering core logic and edge cases • Deployment scripts and step-by-step notes (addresses, gas used, etherscan verification) • Final token address on Ethereum mainnet or a clearly documented test deployment if mainnet is postponed Acceptance criteria...

Hi I will share the details with the shortlisted candidates. Thanks

Hi I will share the details with the shortlisted candidates. thanks

Position: Freelance Smart Contract / Blockchain Engineer Type: Contract / Freelance Location: 100% Remote Workload: Part-time or task-based Compensation: $60–$100/hour (or fixed-price per task) About the Project We are working on DeFi smart contract components, including token implementations and protocol-level logic. Our focus is security, clarity, and real-world usability — not hype. We are building a long-term freelancer pool and looking for engineers who can deliver clean, well-structured Solidity code independently. What You’ll Do Design and implement secure smart contracts using Solidity Work with EVM-compatible chains Review and improve existing smart contract code Follow best practices for documentation, testing, and security Collaborate asynchronously wi...

Design The Role We are looking for a Full Stack Engineer to take full ownership of building a non-custodial crypto payment gateway for USDC on Ethereum. You will not just be "writing code" from a ticket; you will be responsible for the entire delivery, including infrastructure, security, database design, and the admin dashboard. You are effectively acting as the Founding Engineer/CTO for this build. You must be comfortable making architectural decisions, setting up CI/CD, and securing a financial application. The System A compliant, on-chain payment rail that: Generates unique, one-time deposit addresses for users (HD Wallets). Detects incoming USDC transactions (Chain Indexing). Sweeps funds to a central treasury using EIP-3009 (Gasless Permits) to minimize ETH usage. P...

I am launching a fully-independent blockchain network and need an experienced developer who can take the project from white-paper to mainnet. The chain will run on a Proof of Work consensus, operate inside a closed environment (no external chain bridges), and issue a fiat-collateralized stablecoin that functions much like USDT but lives natively on this new ledger. Beyond the core protocol, I will also require built-in wallet support and a smart-contract layer so third-party developers can deploy dApps once the network is live. Security is paramount; every component—from key management to consensus—must be hardened against common attack vectors and accompanied by clear documentation. Key deliverables • PoW node software and full network setup (testnet + mainnet) &bul...

Our new platform, CritiQ, needs a suite of robust, reusable smart contracts. I already have the product vision, tokenomics draft, and high-level user flows; now I’m ready to turn that vision into audited code. Here’s what I expect from this engagement: • Architecture & specification – refine requirements with me and translate them into a concise technical spec. • Development – implement the contracts in Solidity using best-practice libraries such as OpenZeppelin, with comprehensive unit tests in Hardhat or Truffle. • Security & gas optimisation – apply industry-standard patterns, write clear modifiers, and run automated analysis (Slither, MythX, or similar) before handing the code over for an external audit. • Deployment &am...

English: I am planning to build a mobile non-custodial platform for digital token transactions on iOS and Android, including a backend. The software will operate purely with tokens; no fiat processing will occur within the system — fiat transactions will be handled exclusively by connected external partners. In the initial discussion, I expect: • An architecture proposal for Solana, including wallet handling and monitoring logic • Recommendations for the role model: Admin → Distributor → Shop → End Customer • A technical setup for a self-custody wallet with biometric security features • A workflow for QR-based token transfers between roles • A concept for automatic token classification (Clean / Unverified) and an audit trail • A rough ef...

I have an almost–finished Web3 application running on BNB Smart Chain and need an experienced engineer to wrap up the last mile. The heavy lifting is on the contract side, but a clean hand-in demands tight coupling with the existing React/TypeScript frontend. What still needs doing • Write production-ready smart contracts for a referral & level system, staking and vesting mechanics, a level-gated NFT mint, and the accompanying ATA utility token. • Deploy, test, and wire those contracts into the current codebase through Wagmi / connectors. • Guarantee seamless Metamask, WalletConnect, and Trust Wallet interaction, including clear transaction states and error handling. • Close out a handful of UI bugs, polish the UX, and verify that every on-chain ac...