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Daniyal T.

Sialkot, Pakistan

$5/hr
5.0
5 jobs

I am a blockchain developer who has been obsessed with this technology since 2008, when I first stumbled upon Bitcoin as a curious kid with no resourcesโ€”just raw fascination. That early spark never faded. It evolved into hands-on expertise across Ethereum, Solana, Polygon, BSC, Arbitrum, and even Hyperledger, with a recent deep dive into Rust and C++ to explore core blockchain architectures and consensus algorithms. I build things that live on mainnet. A land registration system with 4K+ deeds minted. An NFT marketplace with on-chain royalties. A staking dApp that hit $1.2M TVL across three chains. A Pump.fun sniper bot that executes in sub-second windows. A Solana whale tracker that parses blocks in 200ms. These are not tutorial projectsโ€”they are production systems handling real value and real users. My stack is Solidity, Rust, JavaScript, React, Hardhat, Foundry, web3.js, ethers.js, and AWS infrastructure. I write upgradeable contracts with 95%+ test coverage, optimize gas until it hurts, and treat security as a first-class feature. I have proposed Hyperledger for enterprise CRMs, deployed automated RPC clusters, and debugged bytecode at 2 AM so you do not have to. I am not a coder who happens to know blockchain. I am a blockchain native who learned to code. If your project needs someone who understands both the protocol layer and the user experience, who can architect a smart contract and then explain it to your investors, let us talk. I am available for full-time, contract, or advisory roles, and I start fast. Open to: Solidity audits, dApp architecture, mainnet deployments, cross-chain bridges, DeFi primitives, and anything that pushes this technology forward.

  • Blockchain
  • Blockchain Architecture
  • React
  • DApps
  • Ethereum
  • Solidity
  • Hyperledger Fabric
  • Binance NFT
  • Web3
  • Blockchain, NFT & Cryptocurrency
  • Blockchain Development
  • Blockchain Security
  • Blockchain Platform
  • Layer 2 Blockchain
  • Blockchain Tokenization
Dipe K.

Lagos Island, Nigeria

$20/hr
5.0
14 jobs

I hired Kehinde a year ago for a small WordPress task to test out his skills, And oh boy did he deliver. In fact so much i have trusted him with all the development of my startup - Founder, wellnessplus. Fullstack developer, Telegram Bot, Blockchain project manager & developer, Blockchain Game developer, Fullstack blockchain & smart contract Dapp engineer & auditor. I am an excellent and passionate MERN full stack block chain developer. โœ…Skills & tooling: ๐Ÿ†Front-end ๐Ÿ† โœ” React.js, Redux, Zustand โœ” TypeScript โœ” Styled-component, Tailwindcss โœ” Material UI, Ant Design, BootStrap, HTML, CSS, Canvas โœ” Wordpress ๐Ÿ†Back-end ๐Ÿ† โœ” JavaScript - Node.js, Express.js โœ” PHP - Laravel, WordPress โœ” TypeScript โœ” MySQL & MongoDB - Prisma โœ” Telegram bot โœ” Wordpress ๐Ÿ†Blockchain๐Ÿ† โœ” Swap, Liquidity, Staking, Farming, bridge forking Pancakeswap, Uniswap โœ” Solidity, blockchain game โœ” Smart Contract, Token, NFT, ERC20, BEP20, TRC20, ERC721, ERC1155, EIP2535, Upgradeable smart contract โœ” Blockchain monitor โœ” Web3.js, ethers.js, Hardhat, Mocha, Chai, Brownie โœ” Wordpress โœ… ๐๐ซ๐จ๐Ÿ๐ž๐ฌ๐ฌ๐ข๐จ๐ง๐š๐ฅ ๐’๐ž๐ซ๐ฏ๐ข๐œ๐ž๐ฌ ๐Ž๐Ÿ๐Ÿ๐ž๐ซ๐ž๐: โœ” Presale Launchpad Development โœ” Decentralized Applications (dApps) Initial DEX Offerings (IDO) | Initial Coin Offerings (ICO) | Security Token Offerings (STO) โœ” Smart Contract Development, testing & Auditing โœ” NFT Minting & Marketplace Solutions โœ” Tokenization & Digitization of real-life asset - custom ERC20, ERC721, ERC1155 โœ” Tokenized & Digitization of Real Estate Platforms โœ” DeFi Applications โœ” Staking & Lending Platforms โœ” Yield Farming Protocols & Liquidity Mining Solutions โœ” Decentralized Exchanges (DEX) & Centralized Crypto Exchange Development โœ” Advanced Trading Platforms โœ” Governance Token Solutions & DAO(Decentralized autonomous organization) โœ” Peer-to-Peer (P2P) Lending & Borrowing Protocols โœ” Proficient in Hardhat for deploying & managing blockchain applications across Ethereum test & production environments โœ” Tokenomics Design & Strategy โœ” Development of Decentralized Autonomous Organizations (DAOs) โœ” Exchange Development (CEX | DEX) โœ” Blockchain Whitepaper Writing โœ” Trading Bot Development โœ” Telegram Bot Development โœ” Wordpress development ๐Ÿ”’ Security & Sustainability: I prioritize building secure & reliable solutions designed to stand the test of time. Your peace of mind is always my top priority. โœจ Why Choose Me? I go beyond delivering solutionsโ€”I build lasting partnerships. Driven by a passion for innovation and a commitment to excellence, I help my clients succeed in the digital age. Letโ€™s turn your vision into something extraordinary. Contact me today, and letโ€™s bring your ideas to life!

  • Blockchain
  • Blockchain Development
  • Blockchain, NFT & Cryptocurrency
  • Solidity
  • Web3
  • React
  • Ethereum
  • Ethers.js
  • ExpressJS
  • Node.js
  • JavaScript
  • NFT
  • DApp Development
  • Full-Stack Development
  • Smart Contract
Md S.

Narayanganj, Bangladesh

$20/hr
4.8
117 jobs

Want to work with an experienced Blockchain developer who can bring your smart contract, decentralized application (dApp) vision to life? Are you looking for a Solidity or Rust developer to develop "Gas-Optimized" smart contracts? Whether you're looking to create ERC20 or SPL tokens, ERC721, ERC1155, or NFTs with custom features, concerned about vulnerabilities and exploits in your high-value contracts, need to write tests for contracts, or need a script to interact with leading DEX protocolsโ€”I've got you covered. ๐Ÿ– Some of my previous clients' quotes about me: โœ”๏ธ "...Excellent technical skills and consistently good communication... Completed the project in a timely fashion, exceeding our original deadline." โœ”๏ธ "His work was phenomenal...made sure I understood every step along the way... โœ”๏ธ "..took this project on as if it was his own... Great professional skills, always there to answer questions and suggest the best solutions." โœ”๏ธ "...Every facet of his work was impressive. WOW!" โœ”๏ธ "... goes above and beyond. Md's professionalism and expertise in blockchain are unmatched.." โœ”๏ธ "... communication is excellent, delivery is fast, and his knowledge of smart contracts is impressive." With expertise in EVM-compatible chains (like Ethereum, BSC) and Solana, I specialize in delivering high-performance, gas-optimized smart contracts and dApps tailored to your specific requirements. I help my clients build secure and highly resilient smart contracts, minimizing vulnerabilities and ensuring your code is fortified against exploits. I might be the perfect fit if you're thinking of any of these: โœ… "I need the BEST developer who's as passionate about my success as his own." โœ… "I want someone who will walk me through every step of smart contract interaction." โœ… "Gas fees are too high! My smart contract needs to be lightning-fast and cost-efficient." โœ… "I know blockchain, but I need a professional to make my smart contracts 100% secure." โœ… "Iโ€™m not an Ethereum or Solana expert, and I donโ€™t have time to mess around with dApps." โœ… "Our last dApp was a disasterโ€”I canโ€™t afford to let that happen again." โœ… "I need an EVM-compatible blockchain or Solana expert to cover all my bases for cross-chain or multi-chain applications." Working with me, you will: ๐Ÿ’Ž Gain access to a developer skilled in Python, JavaScript, TypeScript, Rust, Solidity, Brownie, Hardhat, NextJS, Foundry, and Anchor. ๐Ÿ’ŽEliminate vulnerabilities and reduce gas fees during both deployment and interactions. ๐Ÿ’Ž Maximize your DApp's security with continuous follow-ups for improvements. ๐Ÿ’Ž Save time and resourcesโ€”you wonโ€™t need to hire separate back-end, front-end, Rust, or Solidity developers because I handle it all as a full-stack developer. ๐Ÿ’Ž Receive custom scripts to swap, add, or remove liquidity, lend, deposit, borrow, withdraw, and interact across top dApp protocols. ๐Ÿ’Ž Optimize for multi-chain functionalityโ€”Whether you need to bridge Ethereum, BSC, or Solana, I can create solutions that integrate seamlessly across multiple networks. ๐Ÿ– My Skills & Expertise in Blockchain: โ˜‘๏ธSolidity Development for EVM-compatible smart contracts โ˜‘๏ธRust Development for Solana Blockchain โ˜‘๏ธExperience with Chainlink, various ERC standards, and OpenZeppelin โ˜‘๏ธToken development(ERC20/BEP20/SPL) with features like Mintable, Burnable, Reflections, TxFee, Whitelist/Blacklist, and IDO/ICO for tokens. โ˜‘๏ธNFTs (ERC721, ERC1155, ERC404, etc) with Whitelist, Royalties, Presale, Public Sale, Dutch Auctions, IPFS Hosting, and Dynamic NFTs โ˜‘๏ธFull-stack Blockchain Developer with expertise in Solidity, Python (Brownie), JavaScript (Hardhat), Typescript, Rust(Anchor), NextJS, and Foundry. โ˜‘๏ธScript/Program Development for deploying/interacting with smart contracts and protocols like Aave, Uniswap, Raydium, and PancakeSwap. Why Work With Me: ๐Ÿ’ŽExtensive Experience: I've designed and built hundreds of smart contracts from scratch, creating robust back-end scripts for deployment. ๐Ÿ’ŽExpert Problem Solver: Proficient in designing projects from the ground up, solving complex problems, and rapid iterative prototyping. ๐Ÿ’ŽGas Optimization Strategies: I use professional strategies to optimize smart contracts for minimal gas fees and thoroughly test them to identify and prevent potential exploits. My Background in Numbers: โœ”๏ธ Over 3 years of experience with Blockchain technology. โœ”๏ธ Developed numerous DApps and scripts for protocols and tokens, including ERC20, BEP20, SPL, ERC721, and ERC1155. โœ”๏ธ Worked on several growing DApp projects, such as Crowdfunding platforms, Airdrop systems, DEXs, insurance, ICO, IDO, Tokens, Lottery, and NFT marketplaces. โœ”๏ธ Created a variety of smart contracts. โœ”๏ธ Wrote extensive test scripts for smart contracts using Foundry, Hardhat, and Anchor. Sound Like a Fit? Next Steps: Click the green "Invite to Job" button in the top right-hand corner or send me a message, and letโ€™s schedule a call to discuss your project! Otherwise, feel free to book a consultation!

  • Blockchain
  • JavaScript
  • Solidity
  • web3.js
  • Ethereum
  • Smart Contract
  • Blockchain Development
  • DApp Development
  • Cryptocurrency
  • Next.js
  • Blockchain, NFT & Cryptocurrency
  • Smart Contract Development
  • Solana
  • Rust
  • Blockchain Tokenization
Vladyslav K.

Dnipro, Ukraine

$40/hr
5.0
39 jobs

Is your blockchain product ready for real users, or is it a prototype that breaks under live transactions? Most Web3 projects fail at the boundaries between smart contracts, wallets, trading operations, and backend systems. ๐Ÿ† 20+ years architecting production systems at principal engineer level ๐Ÿ“Š $200K+ earned on Upwork across 32 architecture projects ๐ŸŽฏ 100% Job Success Score, Top Rated Plus on Upwork โšก 11 years architecting Fintech / Trading / Accounting solutions โšก 8 years architecting blockchain products across Bitcoin, EVM, Solana ecosystems ๐Ÿ’ผ CEO at Osambit, a 20-person engineering team โœ… Enterprise Blockchain Architect certified, former Sr Principal Engineer at Nordstrom โญโญโญโญโญ "We've had the opportunity to collaborate with the Osambit team, and it's been a great experience. They're highly professional, responsive, and truly understand the final goal. Their technical expertise and ability to deliver on time have been key to the success." (Alwyn V., IXO World) As a Blockchain Architect with 20+ years of production engineering experience and two years focused on Web3, I design blockchain and fintech products that operate reliably beyond a demo. I work across Solana and EVM networksโ€”including Ethereum, Polygon, Base, BSC, and Arbitrumโ€”as well as enterprise platforms such as Hyperledger Fabric and Besu. My work connects secure smart-contract, wallet, payment, and remittance flows with the backend systems, operational controls, and user experiences a real product needs. Every engagement starts with architecture: chain selection, custody and transaction boundaries, compliance-aware workflows, failure modes, scalability, and security. That architecture-first approach helps blockchain and neobanking products withstand live usage, not just testnet scenarios. ๐Ÿ”ถ Centralized exchange: architecture for trading operations, wallet flows, and reliable backend integration ๐Ÿ”ถ Custodial wallets: secure custody, transaction handling, and multi-wallet platform architecture ๐Ÿ”ถ Trading automation system: real-time blockchain-integrated trading workflows with operational safeguards ๐Ÿ”ถ Liquidity automation system: DeFi and liquidity-management automation across Solana and EVM ecosystems ๐Ÿ”ถ Fintech, neobanking & remittance apps: payment, account, wallet, and cross-border transfer architecture ๐Ÿ”ถ Bitcoin mining facility control panel: operational dashboard and control-system architecture for mining infrastructure ๐Ÿ”ถ Blockchain-integrated game: NFT features, token and wallet integrations, and production-ready game backend design ๐Ÿ”ถ Enterprise blockchain solutions: permissioned-network architecture and public-chain integrations using Hyperledger Fabric or Besu ๐Ÿ”ถ Nordstrom (Sr Principal Engineer, 5 years): architected 9+ enterprise systems | led 10 offshore engineering teams | supply chain, payment, logistics domains WHAT I DO โœ… Blockchain Architecture: chain selection, system design, security boundaries, and production rollout planning โœ… Solana Development: Rust programs, SPL standards, RPC integrations, and high-throughput DeFi systems โœ… EVM & Smart Contracts: Solidity development and integrations for Ethereum, Polygon, Base, BSC, and Arbitrum โœ… Wallet & Custody Systems: custodial wallet architecture, secure transaction handling, and multi-wallet integrations โœ… Fintech, Neobanking & Remittance: payment flows, account and wallet systems, cross-border transfers, and operational controls โœ… DeFi, Trading & Liquidity Automation: trading workflows, liquidity systems, DEX integrations, and operational controls โœ… NFT & Tokenized Products: NFT minting, metadata, marketplace and royalty logic, and blockchain-integrated game features โœ… Enterprise Blockchain: Hyperledger Fabric and Besu solutions, permissioned-network architecture, and API or oracle integrations โœ… Full-Stack Web3 Platforms: React interfaces, Node.js or Python backends, web3 integrations, and real-time transaction services โœ… Production Infrastructure: AWS, Docker, Kubernetes, CI/CD, observability, automated testing, and scalable data systems WHO I WORK WITH ๐ŸŽฏ B2B and B2C companies building blockchain products, fintech and neobanking apps, exchanges, wallets, DeFi platforms, or games ๐ŸŽฏ Founders and CTOs who need Web3, payment, or remittance systems running in production with real users and real assets ๐ŸŽฏ Teams with multi-week engagements (4+ weeks minimum), not 5-minute tasks ๐ŸŽฏ Companies that understand blockchain architecture is a system design and security problem, not just a smart-contract problem ๐ŸŽฏ Clients who value senior engineering judgment over the cheapest hourly rate MY PROCESS 1๏ธโƒฃ Architecture Review: 24-hour turnaround on an initial system map, risk review, and scope estimate for your blockchain or fintech product. Close collaboration with business and deep domain immersion. 2๏ธโƒฃ Design: chain selection, smart-contract, wallet, payment, and remittance boundaries, backend integration, and security plan 3๏ธโƒฃ Build: production blockchain or fintech

  • Blockchain
  • Blockchain Architecture
  • Cryptocurrency
  • Ethereum
  • Bitcoin
  • Smart Contract
  • Blockchain Development
  • Web Development
  • JavaScript
  • Python
  • Node.js
  • API
  • React
  • Blockchain, NFT & Cryptocurrency
  • Tokenomics
  • Amazon Web Services
  • Solana
  • Decentralized Exchange
  • PHP
  • Trading Automation
Asad U.

Karachi, Pakistan

$34/hr
5.0
30 jobs

๐Œ๐จ๐ฌ๐ญ ๐ญ๐ž๐š๐ฆ๐ฌ ๐›๐ฎ๐ข๐ฅ๐๐ข๐ง๐  ๐š๐ญ ๐ญ๐ก๐ž ๐›๐ฅ๐จ๐œ๐ค๐œ๐ก๐š๐ข๐ง ๐š๐ง๐ ๐€๐ˆ ๐ข๐ง๐ญ๐ž๐ซ๐ฌ๐ž๐œ๐ญ๐ข๐จ๐ง ๐ ๐ž๐ญ ๐ญ๐ก๐ž ๐š๐ซ๐œ๐ก๐ข๐ญ๐ž๐œ๐ญ๐ฎ๐ซ๐ž ๐ฐ๐ซ๐จ๐ง๐  ๐จ๐ง ๐๐š๐ฒ ๐จ๐ง๐ž. ๐ˆโ€™๐ฆ ๐ญ๐ก๐ž ๐๐ž๐ฏ๐ž๐ฅ๐จ๐ฉ๐ž๐ซ ๐ญ๐ก๐ž๐ฒ ๐›๐ซ๐ข๐ง๐  ๐ข๐ง ๐ญ๐จ ๐ ๐ž๐ญ ๐ข๐ญ ๐ซ๐ข๐ ๐ก๐ญ ๐ญ๐ก๐ž ๐Ÿ๐ข๐ซ๐ฌ๐ญ ๐ญ๐ข๐ฆ๐ž. 4+ years shipping Solana and EVM systems to mainnet and leading the AI agents and LLM-powered systems that run alongside them. Top Rated on Upwork with 100% Job Success across 25+ contracts. Worked on a government-funded blockchain and AI agriculture platform, alongside building tokens with real market caps, AI-driven Telegram bots, and OCR + LLM pipelines that ship to production. Whether you need a smart contract, an AI agent, or a system that combines both, I deliver mainnet-ready code not prototypes. ๐—ฃ๐—ฟ๐—ผ๐˜ƒ๐—ฒ๐—ป ๐—ฅ๐—ฒ๐˜€๐˜‚๐—น๐˜๐˜€ โœ… Worked on a government-funded blockchain & AI-based agriculture traceability platform using Solana Architecture โœ… Built Web3 Rewards Website โ†’ token burn redemption platform deployed on a major Web3 audit platform (SIWE + wallet connect + promo distribution) โœ… Shipped Forge3 โ†’ Web3 escrow protocol that hit $200K market cap โœ… Built ClusterFck โ†’ Solana token analyzer ($158K market cap) with bundle detection and rug-pull risk scoring โœ… Delivered La Suite du Monde โ†’ DAO/NFT membership system for a campaign thats targetting โ‚ฌ1M+ โœ… Built an AI-driven bot for cross-border blockchain remittances with multi-language LLM support โœ… Delivered an AI-powered OCR + audio digitization pipeline for a production book library system ๐—•๐—น๐—ผ๐—ฐ๐—ธ๐—ฐ๐—ต๐—ฎ๐—ถ๐—ป ๐——๐—ฒ๐˜ƒ๐—ฒ๐—น๐—ผ๐—ฝ๐—บ๐—ฒ๐—ป๐˜ โ—† Solana / Anchor / Rust โ†’ modular program architecture, SPL tokens, PDAs, CPIs, Jupiter integrations, on-chain data systems โ—† Solidity โ†’ 20+ mainnet contract deployments. ERC-20, ERC-721, ERC-1155, staking, vesting, presale, custom DeFi logic. Hardhat, Foundry, OpenZeppelin. โ—† Full-Stack Web3 โ†’ Next.js + TypeScript + wagmi/viem + ConnectKit on the frontend. Node.js, Postgres, and Solana/EVM bridges on the backend. SIWE auth, wallet connect flows, production deployment pipelines. ๐—”๐—œ & ๐—”๐˜‚๐˜๐—ผ๐—บ๐—ฎ๐˜๐—ถ๐—ผ๐—ป โ—† LLM Integration โ†’ OpenAI, Anthropic Claude, and Gemini APIs in production systems โ—† AI Agents & RAG โ†’ LangChain, multi-agent orchestration, vector databases, semantic search over domain documents โ—† Workflow Automation โ†’ n8n, Make, Telegram bots, AI-assisted alert and trading systems with retry/error handling โ—† AI + Web3 โ†’ on-chain AI integrations, intelligent token analyzers, AI-driven dApp features ๐—ช๐—ต๐˜† ๐—–๐—น๐—ถ๐—ฒ๐—ป๐˜๐˜€ ๐—›๐—ถ๐—ฟ๐—ฒ ๐— ๐—ฒ โœ” Top Rated with 100% Job Success across 25+ contracts โœ” Mainnet-shipped, production-tested code โ€” not demos โœ” I run a small dev team โ€” can scale up on bigger contracts without losing quality โœ” Honest architectural feedback before you spend an hour coding โœ” Senior-level decisions on architecture, security, and tokenomics from day one ๐—ช๐—ต๐—ฎ๐˜ ๐—–๐—น๐—ถ๐—ฒ๐—ป๐˜๐˜€ ๐—ฆ๐—ฎ๐˜† โญโญโญโญโญ โ€œWith over 25 years of professional experience, itโ€™s genuinely rare to come across talent this professional, committed, and reliable. He is without question one of the best developers Iโ€™ve worked with.โ€ ~ Erick F. If youโ€™re building a smart contract, an AI agent, or a system that combines both send me an invite. Keywords : Blockchain Developer | Solana Developer | Solidity Developer | Smart Contract Developer | Smart Contract Audit | Anchor Framework | Rust Developer | Web3 Developer | dApp Development | DeFi Developer | NFT Marketplace | NFT Development | ERC-20 | ERC-721 | ERC-1155 | Token Development | Staking Contract | Vesting | Presale | DAO | DEX | AMM | SPL Token | Jupiter | PDA | CPI | Hardhat | Foundry | OpenZeppelin | Slither | Mythril | ethers.js | wagmi | viem | web3.js | ConnectKit | RainbowKit | SIWE | MetaMask | Phantom | WalletConnect | Next.js | React | TypeScript | Node.js | Postgres | MongoDB | Laravel | Python | Ethereum | BSC | Polygon | Arbitrum | Base | Optimism | Cross-Chain Bridge | Layer 2 | AI Engineer | AI Agent Development | LLM Integration | OpenAI API | Anthropic Claude | Gemini API | LangChain | LangGraph | RAG Pipeline | Vector Database | Semantic Search | Pinecone | Multi-Agent Systems | Agentic AI | Prompt Engineering | n8n | Make | Zapier | Workflow Automation | Telegram Bot | Discord Bot | Chatbot Development | OCR | Document Digitization | AI + Web3 | Tokenomics | Crypto Trading Bot | MEV | Mainnet Deployment | Top Rated Freelancer

  • Blockchain Development
  • AI Agent Development
  • Solana
  • Ethereum
  • Cryptocurrency
  • Blockchain Security
  • Artificial Intelligence
  • DeFi
  • AI Chatbot
  • JavaScript
  • Data Visualization
  • Analytics Dashboard
  • Smart Contract
  • Claude
  • AI Bot
  • AI Code Generator
  • Rust
  • Solidity
  • Fraud Detection
  • NFT
Adnan A.

Islamabad, Pakistan

$13/hr
5.0
1 jobs

Need a Crypto Wallet, Web3 App, Smart Contract, or Blockchain Mobile App that is secure, scalable, and actually ready to launch? I help startups and founders build non-custodial crypto wallets, multi-chain wallets, Web3 applications, smart contracts, dApps, and React Native mobile apps across Bitcoin, Ethereum, Solana, Base, BNB Chain, Polygon, and other EVM networks. 4+ Years Experience | 23+ Projects Delivered Many Web3 products struggle with the same problems: complicated wallet onboarding, unreliable blockchain integrations, transaction failures, security concerns, poor mobile UX, and developers who understand either blockchain or mobile, but not both. I work across the complete product stack, from wallet architecture and smart contracts to React Native apps and Node.js backends, helping you take a blockchain product from idea to production. What I Can Build Crypto Wallet Development * Non-Custodial & Multi-Chain Wallets * Bitcoin, Ethereum & Solana Wallets * HD Wallets & Secure Key Management * Seed Phrase Creation & Recovery * Token Transfers & Transaction Signing * Token Swaps & DEX Integration * WalletConnect, MetaMask & Phantom Integration * NFT & DeFi Wallet Features Smart Contracts & Web3 * Solidity & Rust / Anchor * ERC-20, BEP-20 & SPL Tokens * Staking & Vesting Contracts * NFT Contracts * DeFi & dApp Development * Web3.js, Ethers.js & Solana Web3.js Mobile & Backend * React Native โ€” iOS & Android * React.js / Next.js * Node.js / Express.js * MongoDB / Firebase * REST APIs & WebSockets * App Store & Google Play Deployment Selected Projects Noottools Multi-Chain Crypto Wallet Built a non-custodial mobile wallet with secure wallet creation, recovery, token management, transaction signing, and blockchain integrations. Web3 Wallet & Chat App Developed a mobile Web3 application combining crypto wallet functionality, blockchain transactions, real-time messaging, and Node.js backend services. DexCrypto Wallet & Exchange Built wallet and exchange functionality with KYC, crypto transactions, wallet management, blockchain APIs, and an administrative backend. MyRay Decentralized Wallet Developed a non-custodial wallet with secure private-key management, wallet recovery, token management, and multi-chain Web3 functionality. Tech Stack Blockchain: Bitcoin โ€ข Ethereum โ€ข Solana โ€ข Base โ€ข BNB Chain โ€ข Polygon Web3: Solidity โ€ข Rust โ€ข Anchor โ€ข Ethers.js โ€ข Web3.js โ€ข Hardhat Mobile: React Native โ€ข iOS โ€ข Android Frontend: React.js โ€ข Next.js โ€ข TypeScript Backend: Node.js โ€ข Express.js โ€ข MongoDB โ€ข Firebase โ€ข REST APIs If you're building a crypto wallet, Web3 mobile app, dApp, token, smart contract, or blockchain platform, send me your requirements and I can help you determine the right architecture before development starts.

  • Blockchain
  • Blockchain Architecture
  • Crypto Wallet Development
  • Crypto Wallet
  • Decentralized Exchange
  • DeFi
  • Smart Contract Development
  • Smart Contract
  • Web3
  • Ethereum
  • Blockchain Development
  • Solidity
  • React Native
  • Rust
  • Android
  • iOS Development
  • Node.js
  • Next.js

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Cost to hire a Blockchain Developer

Cost to hire a Blockchain Developer

Explore typical Blockchain Developer rates and what businesses pay to hire top talent.

Blockchain Developer job description template

Blockchain Developer job description template

Get tips to write a job post that attracts qualified Blockchain Developers.

Blockchain Developer interview questions

Blockchain Developer interview questions

Top interview questions to help you hire the right Blockchain Developers, faster.

Blockchain developer hiring guide

Building with blockchain introduces unique challenges around security, scalability, smart contracts, and decentralized infrastructure. Hiring a blockchain developer gives your team specialized expertise to navigate those complexities, evaluate the right technical approach, and create reliable blockchain solutions aligned with your business goals.

What does a blockchain developer do?

A blockchain developer designs, builds, tests, and maintains decentralized applications and blockchain-based systems. Depending on the project, they may develop smart contracts, DeFi platforms, supply chain solutions, NFT marketplaces, cryptocurrency applications, or other distributed ledger products. Their work combines software development with knowledge of cryptography, consensus mechanisms, blockchain protocols, and smart contract languages.

Blockchain developers typically:

  • Develop decentralized applications (dApps) by building and connecting front-end and back-end components with blockchain networks
  • Write, test, and deploy smart contracts using languages such as Solidity or Rust
  • Build blockchain solutions for use cases such as DeFi, digital assets, supply chain tracking, and NFT marketplaces
  • Integrate blockchain networks with wallets, APIs, databases, and existing applications
  • Apply secure coding practices, testing, and performance optimization to blockchain applications and smart contracts
  • Collaborate with full-stack developers, DevOps teams, security specialists, and product teams to integrate blockchain functionality into broader systems

OLD A blockchain developer builds and maintains decentralized software that uses blockchain technology to deliver secure, transparent, and tamper-resistant applications. Their command of cryptography, consensus mechanisms, and smart contract languages helps organizations unlock efficiencies and new revenue streams that traditional architectures cannot support.

How to hire a blockchain developer on Upwork

Hiring a blockchain developer on Upwork means aligning your project needs with proven technical expertise. Upwork's platform has facilitated more than $25 billion in economic opportunity for talent around the world. You can post a role, compare candidates, and start work in one place. Follow this structured process to run a successful engagement.

Step 1: Post your project

A clear job post helps blockchain developers understand your technical requirements, target network, and expected deliverables.

  • Describe your project and deliverables, such as smart contracts, dApps, wallet integrations, tokens, or blockchain APIs
  • Specify the blockchain networks involved, such as Ethereum, Polygon, Solana, or Hyperledger
  • List required languages, frameworks, and tools, such as Solidity, Rust, JavaScript, Hardhat, or Foundry
  • Define security, testing, scalability, and performance requirements relevant to the project
  • Share your expected budget, timeline, and key milestones
  • Review Upwork's blockchain developer job description template for guidance

For a faster start, try the Job Post Generator, powered by Umaโ„ข, Upwork's Mindful AI. Describe what you need in a few sentences and Uma will draft a job post tailored for blockchain developers. On Upwork, the average time from job post to first proposal is just three hours.

Step 2: Review proposals

Focus on candidates who can demonstrate hands-on experience building blockchain applications similar to yours.

  • Examine portfolios for deployed smart contracts, live dApps, blockchain integrations, or other relevant projects
  • Confirm experience with your target blockchain, programming languages, frameworks, and development tools
  • Look for evidence of secure smart contract development, testing, and deployment practices
  • Explore GitHub contributions or other technical work that demonstrates blockchain development experience
  • Read client feedback for technical execution, communication, and reliable delivery

Uma can conduct instant video interviews to screen applicants and provide a best-fit shortlist with side-by-side candidate comparisons.

Step 3: Conduct interviews

Use interviews to understand how candidates approach blockchain architecture, security, performance, and technical trade-offs.

  • Ask candidates to walk through a past blockchain project and explain the architectural decisions they made
  • Discuss how they test smart contracts and identify potential security vulnerabilities before deployment
  • Explore their approach to transaction costs, scalability, network selection, and other project-specific constraints
  • Ask how they handle contract upgrades, failures, and deployment to testnets and production networks
  • Pose a scenario from your project to understand how they evaluate architecture and security trade-offs
  • Review these blockchain developer interview questions to assess relevant technical skills

Schedule and run live interviews within Upwork Messages, and Uma provides call transcripts and summaries immediately after each call.

Step 4: Agree on scope and begin work

Before work begins, align on deliverables, security procedures, access, testing, and deployment responsibilities.

  • Define deliverables such as smart contracts, dApp components, integrations, tests, documentation, or deployment scripts
  • Set milestones for architecture, development, testing, security review, testnet deployment, and production release
  • Establish version control, code review, testing, and smart contract audit requirements
  • Provide appropriate access to repositories, development environments, APIs, and blockchain infrastructure
  • Define how private keys, wallets, credentials, and other sensitive access will be handled without unnecessarily sharing control of critical assets
  • Agree on deployment responsibilities, documentation, maintenance, and procedures for addressing vulnerabilities after launch
  • Clarify ownership of source code, smart contracts, documentation, and other final project assets

Use the contract workroom and messaging to finalize a contract, onboard your developer, and keep communication in one place, with Uma helping track milestones and next steps. Rely on identity verification, Hourly Payment Protection, hourly tracking, and project funds to keep payments and access secure across each phase.

Upwork is not affiliated with and does not sponsor or endorse any of the tools or services discussed in this article. These tools and services are provided only as potential options, and each reader and company should take the time needed to adequately analyze and determine the tools or services that would best fit their specific needs and situation.

The rates and information provided in this article are based on current data and industry sources available at the time of publication. Freelance rates can vary depending on factors such as experience, location, project scope, and market conditions. Readers are encouraged to conduct their own research to confirm current rates and trends, as this information may change over time.

How much does hiring a blockchain developer cost?

Hiring a blockchain developer generally costs $30-$59 per hour, depending on project scope, security requirements, and the developerโ€™s experience. Project pricing depends on the deliverable; use these typical cost ranges to estimate a budget for your blockchain developer projects:

Smart contract development

$1,000-$3,500/project

Intermediate
  • Solidity contract
  • Unit tests
  • Testnet deployment

Decentralized app (dApp) build

$4,000-$15,000/project

Experienced
  • Web3 front end
  • Wallet integration
  • On-chain logic

DeFi or token protocol

$6,000-$24,000/project

Expert
  • Token contracts
  • Staking or liquidity logic
  • Security hardening

Smart contract audit

$1,500-$5,000/project

Expert
  • Vulnerability review
  • Gas optimization
  • Audit report

Ongoing support and maintenance

$2,000-$8,000/project

Intermediate to experienced
  • Monitoring
  • Upgrades
  • Bug fixes

Frequently asked questions

Is hiring a blockchain developer worth it?

For projects that require smart contracts, dApps, or other blockchain-specific functionality, yes, hiring a blockchain developer is worth it. They bring specialized knowledge of decentralized architecture, smart contract development, and security considerations that general software development may not cover. Security expertise is especially important in this field: Chainalysis reported that nearly $2.2 billion in cryptocurrency was stolen through hacks in 2024, making relevant experience and secure development practices important factors when evaluating candidates.

Whatโ€™s the difference between a blockchain developer and a smart contract developer?

A blockchain developer builds and integrates full decentralized systems, including networks, nodes, and application layers, while a smart contract developer focuses on writing and testing the self-executing contracts that run on those networks. Many freelancers do both, though larger projects often split the roles.

How long does it take to build a blockchain application?

A relatively simple smart contract or blockchain integration may take a few weeks, while a full dApp or DeFi platform can take several months. Timelines vary based on complexity, integrations, testing, security reviews, and deployment requirements, so defining the feature set and milestones early can help you plan more accurately.