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    5,000 Ethereum jobs found

    I need a full-stack developer who can build a launchpad. You should be familar with experience with and pump fun logic We will have uniswap v2 pool and classic mode as Please give us the quote and timeline to build this launchpad

    $21 / hr Average bid
    $21 / hr Avg Bid
    73 bids

    ...tracking dashboard or documented API • Brief handover session and technical documentation Acceptance criteria: contract passes standard Tronscan verification, staking rewards calculate correctly over three test cycles, and wallet interactions run error-free in TronLink on mainnet. Although Tron is the preferred chain, I am open to hearing how you might future-proof the codebase for porting to Ethereum, Binance Smart Chain, or Polkadot later on....

    $694 Average bid
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    16 bids

    I’m building a decentralised portal that lets students handle every administrative step—from opening a profile to paying tuition—directly on Ethereum. The site must: • let users connect a MetaMask (or any Web3) wallet, create a personal profile and register as a student • allow real-time course browsing, enrollment and on-chain fee payment in ETH or an ERC-20 we define • route each payment and enrollment request to an admin dashboard where staff can verify KYC details, approve or reject registrations and manage fee settlements • store all critical actions in Solidity smart contracts, fully tested and verified on Etherscan, with events that keep the front-end in sync • give admins rich analytics—total fees collected, outstandi...

    $84 Average bid
    $84 Avg Bid
    19 bids

    ...* Good understanding of Bitcoin, cryptocurrency and mining * Knowledge of PoW and PoS * Understanding of Smart Contracts * Familiarity with Hyperledger * Understanding of IPFS and NFTs * Ability to explain technical concepts clearly to undergraduate students * Good classroom communication and presentation skills * Prior academic or corporate training experience is preferred Experience with **Ethereum, Solidity, Hyperledger Fabric, Web3 or blockchain-based applications** will be an advantage. ### Student Activities The trainer will also guide students through curriculum-related activities such as: * Case study on blockchain mining, cryptocurrency and mining pools * Discussion on blockchain integrity * Student presentation on blockchain applications and digital asset management...

    $10 / hr Average bid
    $10 / hr Avg Bid
    1 bids

    I need a seasoned blockchain developer to wire a multi-wallet flow into my existing iGaming platform. Players must be able to make deposits, withdraw winnings, and move balances between their own on-site wallets while we quietly sweep funds into our hot and cold vaults for risk management. Currencies in scope are Bitcoin (BTC), Ethereum (ETH), Litecoin (LTC), and SOL. The front-end is React/, the back-end exposes REST and GraphQL endpoints, and we already run a PostgreSQL ledger that records every chip and token—your job is to connect on-chain activity to that ledger with real-time confirmations and webhook callbacks. Key requirements • End-to-end handling of Deposits, Withdrawals, and Transfers between wallets. • Automated sweeps batching user balances into pr...

    $33 / hr Average bid
    $33 / hr Avg Bid
    148 bids

    I need a complete blockchain-powered backend whose main role is to run and interact with smart contracts. Your task is to design, code, test, and deploy those contracts and then expose their functions through a clean API that my front-end team can consume. The choice of chain and contract language is open; whether you prefer Ethereum, Hyperledger, or Binance Smart Chain, and whether you work best in Solidity, Rust, or Vyper, I am happy to follow your technical lead as long as the solution is secure and maintainable. Security, gas or resource efficiency, and clear documentation matter most to me. The API should support standard CRUD-style interactions with contract state and include basic authentication so we can drop it straight into our staging environment. Deliverables • ...

    $1169 Average bid
    $1169 Avg Bid
    188 bids

    ...Unity, Unreal Engine, or another proven toolset, the same codebase should compile cleanly for Windows/macOS and iOS/Android. For the wallet layer the only coin I need live on day one is USDT. Deposits, in-game wagers, and instant withdrawals are mandatory, wrapped in a clean interface that feels native to each platform. I’d like the contract/API architecture kept modular so adding Bitcoin or Ethereum later is straightforward. KYC hooks, rate-limited withdrawals, and basic admin reporting (volume, active users, game results) round out the back office. Successful delivery means: • PC, iOS, and Android builds install and run without crashes • Ball physics and game rules match standard eight-ball regulations • A test USDT transaction moves from external wa...

    $527 Average bid
    $527 Avg Bid
    67 bids

    DID YOU BUILT AN ENTIRE SOVEREIGN CROSS CHAIN PROTOCOL FROM THE GROUND UP? CONTROL Testnet is where you build and verify the engine $50 EACH MODULE PAID AFTER VERIFIED DELIVERY ONLY MODULE 1: Subsidy Pool| Built | Deploy via Hardhat / Foundry | MODULE 2: UTXO Harnes | Built | Run live testnet tests | MODULE 3: Relayer Daemon | Built | Initialize with `.env` config | MODULE 4: Alt-UTXO Adapters| Built | Configure RPC endpoints | MODULE 5: EVM PoW Deploy | Built | Deploy to ETHW / Syscoin testnets | MODULE 6: Monero Adapter| Built | Connect to `monero-wallet-rpc` | MODULE 7: Beldex Adapter | Built | Connect to `beldexd` | MODULE 8: Frontend Bridge| Built | Inject into HTML UI & test | Detailed Scope of Work (The 8 Modules) MODULE 1: Subsidy Pool (Solidity) Needs deployment via Hardh...

    $137 Average bid
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    19 bids

    I need Bitget Wallet wired into my existing decentralized application so users can connect on Ethereum and enjoy the same smooth experience they already have with the other wallets we support. Core scope • Establish a reliable connection flow: detect Bitget Wallet, prompt connection, and surface the user’s ETH address in the UI. • Enable full transaction capability on Ethereum—send and receive assets, sign messages, and interact with our deployed smart contracts seamlessly through or web3.js. • Pull and display the user’s recent Ethereum transaction history inside the app. • Keep the current code-base untouched where possible and document every new function so future maintenance is straightforward. I’m open to you...

    $36 Average bid
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    70 bids

    ... or similar) • Admin-friendly dashboard so I can update content, swap contract addresses, or push announcements without editing code • SEO-ready pages and basic analytics hooks so we can monitor viral traction from socials Tech you’re welcome to propose: React + , Vue, or another performant stack you’re comfortable shipping quickly; smart-contract calls are already live on Ethereum, so no contract work is needed—just front-end hooks and API endpoints. Success looks like: 1. Visitors can connect their wallet and transact without leaving the site. 2. UI/UX meets the polished, finance-grade standard of “professional and sleek.” 3. Code is clean, documented, and deploys painlessly to an AWS, Vercel, or similar environment. If this ...

    $429 Average bid
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    170 bids

    ...wallet that runs smoothly on iOS and Android. Private keys must never leave the user’s device, and the experience needs to feel as simple as any mainstream payments app. Core feature set • Send and receive cryptocurrencies with QR scanning and shareable wallet addresses • Real-time and historical transaction list with clear status indicators • Multi-currency support from day one (Bitcoin, Ethereum/ERC-20 preferred) and an architecture that lets us add new assets quickly Security and recovery • Biometric authentication (Face ID / Touch ID / Android Biometrics) • Optional two-factor authentication before approving a transaction • Passphrase backup that users can export, verify, and import at any time Under the hood I expect: ...

    $714 Average bid
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    33 bids

    I’m ready to allocate a minimum of ₹1 lakh exclusively into cryptocurrency, but I don’t want the usual Bitcoin-or-Ethereum route. My interest lies in promising altcoins that can realistically compound into a steady ₹10 k return every month while still keeping the overall objective of long-term growth in focus. Here’s what I need from you: • A researched, data-backed portfolio allocation concentrated on lesser-known coins with solid fundamentals, clear use-cases, and active development. • Defined buy-in ranges, position sizes, and a rebalancing schedule that protects capital yet targets the 10% monthly yield I’m after. • Risk-mitigation tactics—stop-loss levels, diversification ratios, and contingency plans for market downturns. &bu...

    $10 / hr Average bid
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    1 bids

    ...to learn new software and platforms quickly. * Reliable internet connection and a suitable home-office setup. * Ability to work independently with minimal supervision. * High level of discretion when handling confidential employee, financial, and business information. ### Crypto Knowledge – Required Candidates should be comfortable explaining and working with concepts such as: * Bitcoin and Ethereum * Stablecoins such as USDT and USDC * Crypto wallets and wallet addresses * Blockchain networks * Sending and receiving cryptocurrency * Transaction hashes and blockchain explorers * Basic crypto security practices * Crypto payments and contractor compensation * Basic understanding of DeFi/Web3 terminology **This is not a role for someone who simply has an interest in crypto...

    $13 / hr Average bid
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    7 bids

    ...(token-gated) mediante el estado de contratos inteligentes o firmas en el backend Web2.5, garantizando derechos de comunicación exclusivos para los miembros autorizados. 2. Requerimientos Funcionales y Técnicos Core A. Control de Acceso Token-Gated y Autenticación (Capa Web2.5) * Identidad y Autenticación: Implementación de autenticación Web3 mediante wallets EVM/Solana (SIWE - Sign-In with Ethereum o equivalente) integrada con abstracción de login social Web2.5 (ej. Privy, Dynamic o Web3Auth). * Motor de Validación de Acceso (Gating): * Verificación en tiempo real del estado de membresía (balance ERC-20/ERC-721, Soulbound Tokens o claims JWT firmados desde el backend) previo a la iniciación de...

    $2223 Average bid
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    72 bids

    ...different crypto wallets and document the execution quality of each swap. Requirements For each wallet: Perform one swap using the wallet's native swap feature. Use the same trading pair and approximately the same trade size across all wallets whenever possible. Record the following information: Wallet, Test date, and Device and OS Wallet name and version Pair and network Example: ETH → USDT on Ethereum Amount sent Amount of the input token Rate shown Exchange rate quoted by the wallet immediately before confirming the swap Market rate (same minute) Market price from a reputable source at the time of execution Amount received Final amount received Gas paid Network fee paid Total cost against market Difference between the theoretical market value and the actual outcom...

    $926 Average bid
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    20 bids

    I’m launching a DeFi application on the Ethereum network and need a developer who can take full ownership of the smart-contract layer. The core goal is to design, code, and deploy Solidity contracts that power the protocol’s functionality while keeping security and gas efficiency front of mind. Key expectations • Architect and write production-ready smart contracts for a DeFi application (Solidity on Ethereum). • Create migration/deployment scripts and configure Hardhat or Truffle for local and testnet environments. • Build a concise test suite (Mocha/Chai or similar) covering edge cases, exploits, and upgrade paths. • Optimise gas usage and follow current best practices for re-entrancy guards, overflow checks, and access control (Open...

    $421 Average bid
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    42 bids

    ...customer's identity is verified, the verified KYC data can be reused across multiple banks, reducing duplicate verification, saving time, and lowering operational costs. A credit assessment module analyzes the customer's financial information and credit history to support fair and faster credit allocation. Technologies Used: Frontend: HTML, CSS, JavaScript Backend: Java, Spring Boot Blockchain: Ethereum, Solidity, Web3j Database: MySQL Key Features: Secure and decentralized KYC storage Tamper-proof customer records using blockchain Smart contract-based KYC verification Faster and transparent loan approval process Reduced fraud and duplicate KYC submissions Improved customer trust and data privacy Outcome: This project enhances the security, transparency, and efficien...

    $5 / hr Average bid
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    26 bids

    I'm seeking an experienced developer to create a flash loan website connecting to major DeFi protocols: Aave, Uniswap, and Compound. Flash USDT The platform should feature: - Loan calculator: To estimate loan amounts and costs. - Real-time mar...calculator: To estimate loan amounts and costs. - Real-time market data: To provide updated info on asset prices and market conditions. - User dashboard: For tracking loans, repayments, and portfolio performance. Ideal candidates will have: - Strong background in DeFi and blockchain technology. - Experience with building financial tools and dashboards. - Proficiency in smart contracts, particularly on Ethereum. - Ability to integrate real-time data feeds. Please provide examples of similar projects and your approach to security and u...

    $282 Average bid
    Urgent
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    94 bids

    ...for an experienced developer to help us expand it into a production-ready marketplace. Here is what I'm after: - Develop a modern, responsive web application using React/ (or a similar framework) with a clean and intuitive user experience. - Build scalable backend services using Node.js, , and PostgreSQL to manage users, assets, marketplace data, and transactions. - Integrate Ethereum/Polygon smart contracts (ERC-721/ERC-1155) for asset tokenization and ownership management. - Implement wallet connectivity (MetaMask, WalletConnect, etc.) and support secure blockchain interactions. - Develop marketplace features, including: * Browse and search tokenized assets * Advanced filtering and sorting * Asset detail pages * User portfolios * Auctions and direct trading

    $53 / hr Average bid
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    213 bids

    I need a developer who can build a web-based payment flow that accepts both one-time and recurring transactions, routes them through Coinbase Commerce, and settles funds directly to a specified USDT wallet address. In addition to USDT, I also want the platform to accept Ethereum (ETH). Core objectives • Embed a checkout experience that supports single purchases as well as subscription billing. • Use the Coinbase Commerce API to create, track, and confirm invoices. • Automatically convert or settle balances to my USDT wallet address once each invoice clears. • Allow ETH payments to follow the same confirmation and settlement logic. • Provide a lightweight admin page or dashboard where I can view payment status, issue manual refunds, and export ba...

    $1021 Average bid
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    164 bids

    I’m finalising a short-term build on the Ethereum blockchain and have reached the stage where I need specialist help with two closely related pieces: • Raw transaction creation – crafting, signing and broadcasting the low-level transactions (RLP encoding, nonce and gas management, offline signing, etc.) that will deploy and interact with the contract. • A bespoke token smart contract – the core logic is outlined but still flexible; I want to be certain the code is solid, secure and optimised before it goes live. Here’s what I’m expecting from our collaboration: 1. Review or write the Solidity for this custom token contract, compile it and demonstrate successful deployment on a public testnet. 2. Produce example raw transactions for key a...

    $49 Average bid
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    27 bids

    I need help crediting my Redotpay wallet with USDT. The balance will be coming from my own personal wallet. For the network, I indicated “Redotpay” because the app itself does not make the underlying chain obvious, so I will rely on you to confirm whether I should send over Ethereum (ERC-20), Tron (TRC-20) or Binance Smart Chain (BEP-20) based on fee structure and compatibility with Redotpay’s deposit addresses. Here is what I am looking for: • Clear, step-by-step instructions to generate the correct deposit address inside Redotpay and verify it matches the chosen chain. • Guidance on any required minimum amount, confirmations, or reference fields Redotpay may ask for during the transfer. • A quick safety checklist so I can double-check e...

    $133 Average bid
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    6 bids

    ...ConfidentialPayroll protocol across Ethereum, Solana, and other VMs Integrate zero-knowledge proof systems (Ligero/Arc) for transaction privacy and compliance Implement cross-chain settlement mechanisms using Circle's CCTP and Hyperlane Integrate FHE (Fhenix/Zama) for encrypted state management of payroll rosters Build and maintain the backend API orchestrator (Express/TypeScript) to manage the 7-stage payment pipeline Write secure, well-tested, and documented code for our core infrastructure Collaborate with the team on architecture decisions and technical roadmap REQUIREMENTS 3+ years of software development experience, with at least 2 years of hands-on blockchain development Deep expertise in Solidity and experience with EVM-compatible chains (Ethereum, Ba...

    $2812 Average bid
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    33 bids

    Consultation on multisig architecture for USDT (TRON, BSC, Ethereum) What needs to be done: conduct an independent expert consultation on implementing multisig wallets to protect the treasury funds of a company that processes high-volume USDT payments simultaneously across three networks - TRON (TRC20), BNB Smart Chain (BEP20), and Ethereum (ERC20). Required: (1) provide an overview of available solutions on the market and recommend the optimal one for our profile - a single custodial platform for all three networks or a combination of separate tools for EVM and TRON; (2) propose a signature architecture (e.g. 2-of-3), key distribution across roles, and thresholds for small/large payouts; (3) provide recommendations on key storage (hardware wallets, HSM) and procedures in ca...

    $54 / hr Average bid
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    15 bids

    ...someone who can independently manage the complete recruitment lifecycle—from sourcing top talent to coordinating interviews and helping us hire the right candidates. What You'll Be Hiring For We are actively hiring: • Full Stack Developers • Frontend Developers (React, , Vue.js, Angular) • Backend Developers (Node.js, NestJS, Python, Django, .NET, Java) • Blockchain Developers (Solidity, Ethereum, Polygon, Solana, Web3) • AI & Data Engineers (Preferred) • DevOps Engineers (Preferred) Responsibilities • Manage the complete recruitment process from start to finish. • Create and optimize job postings on Upwork and other relevant platforms. • Source high-quality candidates using LinkedIn, GitHub, Upwork, and other channels. ...

    $126 Average bid
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    53 bids

    ...Blockchain Verified Global Verification Privacy First Permanent Record The headline and primary CTA should remain the strongest visual focus. Design Principles The Hero should immediately answer: What does this platform do? Why should I trust it? Why is it different? Why should I use it? The Hero should explain the platform visually—not simply decorate the page. Please Avoid Do NOT use: Bitcoin symbols Ethereum logos Cryptocurrency graphics Trading charts NFT artwork Cybersecurity shields Locks Padlocks Luxury cars Sports cars Watches Yachts Gold bars Diamonds Random expensive objects Generic AI-looking artwork Busy layouts Too many floating objects Device mockups (phones, tablets, laptops) as the main Hero visual Focus on proof of ownership, verification, and trusted docum...

    $20 Average bid
    Guaranteed
    $20
    151 entries

    I want a web platform where players deposit Bitcoin, Ethereum, or Litecoin, open randomized loot-box style cases, and instantly withdraw any winnings they decide to cash out. The flow should feel identical to popular skin-unbox sites, but with native crypto handling from start to finish. Core Experience • Seamless wallet connection or generated in-site wallet for BTC, ETH, and LTC • Provably-fair RNG powering the randomized loot boxes so users can verify each roll • Live animation of every unbox, plus a running feed that highlights big pulls to keep the page energetic • Instant smart-contract or API-driven payouts when a player clicks “withdraw” • Simple, responsive UI that works on desktop and mobile Admin Side • Dashboard tha...

    $7037 Average bid
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    82 bids

    I need a complete, verifiable list of every Ethereum wallet that has ever transacted directly with a single, specified address. My goal is simple: extract the “address IDs” only—no amounts, timestamps, or hashes—then deliver them in a clean, deduplicated list (CSV or JSON is fine). You are free to leverage Etherscan, Arkham Visualizer, , or any other reliable on-chain parsing method, as long as the logic is reproducible. A short script or notebook that I can rerun later to refresh the list will be part of the hand-off. Acceptance criteria • Exhaustive coverage of all historical transactions to and from the target address on Ethereum mainnet • One row per unique counterparty address, no duplicates • Delivery of both the list file ...

    $135 Average bid
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    16 bids

    ...possible. You will collaborate directly with our front-end team; once a contract is ready, you’ll expose ABI endpoints, write simple integration docs and jump on a quick call if something breaks in staging. Expect regular code reviews on GitHub, coverage reports in CI, and at least one external audit before we push to production. What I’m looking for • Proven track record of shipping contracts on Ethereum or any other EVM chain. • Fluency with ERC-20/721 standards, proxy patterns, and OpenZeppelin libraries. • An eye for security: re-entrancy, overflow/underflow, access control, oracle manipulation, the works. • Ability to translate product specs into modular, well-commented code and anticipate edge cases early. • Clear, timely com...

    $1094 Average bid
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    120 bids

    I’m ready to move from concept to working MVP for a fully decentralised, zero-fee crowdfunding platform on Ethereum. Campaign creators will deploy a dedicated smart contract that collects ETH directly, so backers interact only with the chain—no custodial wallets or middlemen. The attached docx lays out user flows, contract interface, and UI wireframes; you’ll turn that vision into code. Key context • Our creators’ core need is simple: raise funds for their projects. • The first public release will showcase technology-focused campaigns, giving us a clear niche to test traction before we expand. What I need from you 1. Develop and thoroughly test the Solidity contracts exactly as specced, including create-campaign, contribute, refund, and with...

    $17 / hr Average bid
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    168 bids

    I’m looking for an experienced blockchain developer who can create a fully compliant security token whose core purpose is to provide holders with investment returns. I’m flexible about both the token’s classification (utility, asset-backed, or equity) and the underlying chain (Ethereum, Binance Smart Chain, Stellar, or another you recommend). What matters most is that the structure meets relevant securities regulations and is technically sound. Key objectives • Design the token’s economic model and compliance flow so investors receive returns legally and transparently. • Write and audit the smart contract code (Solidity or the language suited to your chosen chain) with features such as transfer restrictions, whitelisting/KYC hooks, dividend or pr...

    $313 Average bid
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    23 bids

    ...ownership of each transaction and me, as the store owner, iron-clad control over inventory, payments and dispute resolution through smart contracts. The build needs to cover the full stack: a responsive web storefront, the back-office admin dashboard and the on-chain layer that processes orders, handles payments in crypto and records delivery milestones immutably. I’m open on whether we use Ethereum, BNB Smart Chain, Solana or another network; what matters most is a secure, gas-efficient and future-proof solution. Bring your own recommendations and explain why they fit. Deliverables • Production-ready smart contracts with clear comments and unit tests • Modern web UI/UX (React, or similar) wired to the contracts via Web3 / • Crypto and fiat paymen...

    $544 Average bid
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    205 bids

    I want a small, self-contained PHP script with a browser-based GUI that sits on my Linux server and lets me swap my own ERC-20 token (the one I already hold in MetaMask) for ETH on the Ethereum Mainnet. The interface should: • Detect the connected MetaMask wallet, display the token balance, and let me enter how many tokens to convert. • Allow me to define and later update the conversion price (token-to-ETH rate) from a simple settings panel so I can run private sales without touching the code. • Build and sign the transaction client-side via MetaMask, then broadcast it so the user receives ETH back to the same wallet once the swap succeeds. • Show clear status and Tx hash feedback while the transaction confirms. Please keep the script focused on this sing...

    $421 Average bid
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    24 bids

    I want a production-ready flash-loan arbitrage bot that operates on Ethereum and combines Aave flash loans with price opportunities across Uniswap and Sushiswap. The core workflow is: • Pull live on-chain and off-chain prices, detect profitable spreads in milliseconds. • Instantly launch an Aave flash loan, route the borrowed amount through Uniswap and Sushiswap, and repay the loan plus fees within the same block. • Optimise gas by simulating each bundle and selecting the lowest-cost route before submission. Key requirements • Real-time price monitoring with sub-second latency (I’m happy to run a dedicated node or use WebSocket endpoints if that helps). • Fully automated trade execution from detection through settlement, no manual clicks. ...

    $2034 Average bid
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    96 bids

    ...blockchain engineer I can rely on for a steady stream of work. The assignments range from writing and testing production-grade smart contracts to troubleshooting main-net deployments, building full dApps, and occasionally reviewing other developers’ code for security and gas optimisation. Because our clients come with very different ideas, you should be comfortable jumping between chains such as Ethereum, Binance Smart Chain, or even Polkadot when required, and you’ll likely touch Solidity most days, with Rust or Go popping up on some specialty jobs. If you have strengths in only one of those stacks, that’s fine—we can shape early tasks around your core expertise and then branch out together. Typical week-to-week work might involve: • Designing and...

    $32 / hr Average bid
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    76 bids

    SUPERAGENT v4.1 IRONCLAW — AI Agent Crypto + Dev (37 Skills, Self-Hosted, Hermes-Compatible) 37 SKILL MODULES (semua include): Crypto/Web3 (H1-H10): • Swap token multi-chain (Ethereum, BSC, Solana, Base) • Bridge cross-chain (LayerZero, Stargate, ) • DeFi ops (Aave, Lido, GMX, Hyperliquid, Pendle) • Token sniping (anti-honeypot, rugcheck, GoPlus) • Mempool watch + whale tracker (Nansen, Arkham) • NFT marketplace (Blur, Magic Eden, Tensor, OpenSea) • Smart contract read/write (ABI inspector, proxy, EIP-712) • Deploy contract (Foundry, Solidity, CREATE2) • SIWE/WalletConnect auth • Browser automation untuk dApps (Playwright) Automation/Dev (m-cluster): • Telegram/Discord bot (cron, webhook, auto...

    $555 Average bid
    $555 Avg Bid
    91 bids

    ...blockchain engineer I can rely on for a steady stream of work. The assignments range from writing and testing production-grade smart contracts to troubleshooting main-net deployments, building full dApps, and occasionally reviewing other developers’ code for security and gas optimisation. Because our clients come with very different ideas, you should be comfortable jumping between chains such as Ethereum, Binance Smart Chain, or even Polkadot when required, and you’ll likely touch Solidity most days, with Rust or Go popping up on some specialty jobs. If you have strengths in only one of those stacks, that’s fine—we can shape early tasks around your core expertise and then branch out together. Typical week-to-week work might involve: • Designing and...

    $32 / hr Average bid
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    52 bids

    I’m ready to put a portion of my portfolio to work in Ethereum and a carefully selected basket of altcoins, with the clear aim of building long-term value rather than chasing quick flips. I need a seasoned crypto trader who can shape a disciplined strategy, execute the actual buys and sells for me, and monitor the positions over time. Here’s what matters to me: • Evidence of a proven, data-driven approach that suits multi-month or multi-year horizons. • Thoughtful coin selection beyond ETH—quality projects with solid fundamentals and reasonable tokenomics. • Risk controls (position sizing, re-balancing schedules, stop-loss logic) that protect downside without forcing premature exits. • Regular, concise performance reports so I always kn...

    $476 Average bid
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    10 bids

    ...possible three-leg price loops, calculate net profitability after trading and withdrawal fees, and instantly execute the cycle whenever a preset threshold is met. Key points I need respected: • Strategy: pure triangular arbitrage; no cross-exchange spread trading. • Exchanges: Binance and Bybit only, with simple JSON/YAML files for my API keys and adjustable parameters. • Assets: Bitcoin, Ethereum and Ripple pairs (for example BTC/USDT, ETH/BTC, XRP/ETH, etc.). • Safety: position sizing, failed-leg rollback, and a dry-run mode so I can test live order books without placing real orders. • Clarity: modular functions, clear comments, and a concise README that explains installation, config variables and how profit is computed. Please code as simply ...

    $522 Average bid
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    3 bids

    ...authentication on every outbound transaction as well as on any sensitive settings screen. I’m happy to discuss SMS, email, or authenticator-app–based 2FA—choose whichever you can implement most robustly. I’m aiming for a straightforward user experience with optional room to grow: even though the initial scope covers Bitcoin exclusively, the architecture should be modular enough that I can add Ethereum, Litecoin, or other chains later without a full rewrite. Deliverables • Fully functional Android and iOS apps (React Native, Flutter, or native—open to your recommendation). • Secure backend or trusted third-party API integration for balance and UTXO handling. • Source code pushed to a private repo with clear build instructions. &...

    $5247 Average bid
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    52 bids

    ...000 to $140,000 per year, paid monthly. Role Overview We are hiring a senior Blockchain Engineer to help design and build a copy trading protocol with on-chain vaults, relay contracts, and cross-chain settlement infrastructure. The role requires production-grade experience across Ethereum, Solidity, DeFi systems, and security-focused smart contract development. Technical Requirements Candidates should have 4+ years of professional experience and strong hands-on expertise with: Solidity 0.8.25+ and Foundry Ethereum and EVM architecture , , and TypeScript Rust and Solana development DeFi protocols and on-chain trading systems Git, Docker, and CI/CD pipelines Security auditing, testing, and mainnet-fork workflows Cross-chain infrastructure and blockchain integrations Addition...

    $8189 Average bid
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    13 bids

    I nee...Alongside the contract, I want a lightweight web dApp that lets users connect with MetaMask, view total supply, and call the mint function in a single, smooth flow. A clean React or front end with is fine; if you prefer Vue or another modern stack, I’m open as long as the UX is clear and responsive. Key acceptance criteria: • Verified, optimised Solidity code deployed on Ethereum mainnet (testnet first for review). • Minting controlled by owner role, with events properly emitted. • Front-end fully wired to the contract, wallet-connect ready, and deployed to a public URL. • Full hand-over of source (Solidity, front-end, and deployment scripts). Once we agree on milestones I’ll supply the token name, symbol, and any branding asse...

    $33 / hr Average bid
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    62 bids

    I need a web-based trading platform that I can fully manage from an admin console. After a quick email-and-password signup, each user should automatically receive both a profile and a unique, custodial wallet address. At launch the platform will handle Bitcoin and Ethereum; the codebase must be structured so I can add further coins later without a full rewrite. Key functions I must have as the administrator: • Real-time dashboard showing every registered account, current balances, recent deposits, and withdrawal requests. • Ability to push crypto from a master wallet into any user wallet on demand. • Withdrawal workflow that blocks release of funds until the user pays a configurable fee I set in the backend. User-side essentials: • Responsive trading interf...

    $382 Average bid
    $382 Avg Bid
    78 bids

    ...snippets, or quick-fire TikTok captions—whatever medium best carries the message. You’ll pull raw data from sources like CoinMarketCap, TradingView, Glassnode (or similar tools you prefer), spot the headline movement, add a dash of context, and wrap it in language that makes sense to both newcomers and seasoned crypto watchers. Deliverables • 4–6 social posts per week focused on Bitcoin, Ethereum, and notable altcoins • One-sentence headline, a concise 100–150-word explanation, and 1–2 key data points or charts (link or image) per post • Engaging hashtags and a clear call-to-action that fits the platform • Content formatted and scheduled in a shared Google Doc or directly in the platform’s draft area, ready for my...

    $147 Average bid
    $147 Avg Bid
    5 bids

    I need an experienced blockchain coder to handle the entire smart-contract layer of my upcoming project. The priority is clean, secure smart contract development—from architecture through deployment—while keeping gas costs and upgradeability in mind. I have not locked in a chain yet, so if you are comfortable on Ethereum, Binance Smart Chain, Polkadot, or can justify another EVM-compatible network, please outline why it fits. I’m equally open on the contract’s purpose: token logic, an NFT framework, or a back-end for a dApp are all in scope; the key is that the code is solid and audit-ready. Deliverables • Full Solidity (or relevant) source with in-line comments • Comprehensive unit tests and deployment scripts (Hardhat or Truffle preferred) ...

    $40 / hr Average bid
    $40 / hr Avg Bid
    30 bids

    ..., yet is entirely my own codebase. The core idea is simple: visitors browse an inventory of digital gift cards, drop any value they like into a shopping cart, and pay a single on-chain invoice. The moment the network confirms the payment, the platform releases the card codes—no extra fees for the buyer, no hidden spread. Cryptocurrencies to be accepted from day one are Bitcoin, Ethereum, Monero, Solana, XRP and Litecoin. I intend to self-host full nodes for every coin, so the back-end must talk directly to those nodes, not to third-party gateways. Please architect the payment module so I can plug in or remove coins later without touching the rest of the code. Security is non-negotiable: • End-to-end HTTPS, HSTS and secure headers • Hot wallet keys never stor...

    $876 Average bid
    Urgent
    $876 Avg Bid
    63 bids

    ..., yet is entirely my own codebase. The core idea is simple: visitors browse an inventory of digital gift cards, drop any value they like into a shopping cart, and pay a single on-chain invoice. The moment the network confirms the payment, the platform releases the card codes—no extra fees for the buyer, no hidden spread. Cryptocurrencies to be accepted from day one are Bitcoin, Ethereum, Monero, Solana, XRP and Litecoin. I intend to self-host full nodes for every coin, so the back-end must talk directly to those nodes, not to third-party gateways. Please architect the payment module so I can plug in or remove coins later without touching the rest of the code. Security is non-negotiable: • End-to-end HTTPS, HSTS and secure headers • Hot wallet keys never stor...

    $838 Average bid
    $838 Avg Bid
    83 bids

    I need a production-ready smart contract written for Ethereum that will handle straightforward financial transactions, then wrap it in a clean single-page dApp so end-users can interact with it without touching the command line. The contract must be solidly coded in Solidity, thoroughly tested, and deployed to the mainnet once we finish our reviews. On the front-end I want a lightweight React (or similar) page that talks directly to the contract. Wallet integration is essential—MetaMask and any other common Web3 wallets should connect seamlessly so users can approve, send, and monitor transactions. A clear, searchable transaction history pane is the second must-have so people can verify their activity in real time. Beyond those core pieces I have several additional features...

    $34 / hr Average bid
    $34 / hr Avg Bid
    104 bids

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