The ultimate guide to hiring a web developer in 2021
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Blockchain, is a technology that encompasses digital records or information, referred to as “blocks”, that are linked together securely and share the same network. This distributed ledger technology is the backbone of a new wave of innovation being implemented into our lives, with new disruptive applications and solutions seen in a growing number of industries. Clients may hire a Blockchain Developer to harness this power and build a secure digital platform tailored to their business needs.
A Blockchain Developer can create unique solutions leveraging blockchain technology to securely store, access, mine and distribute data in an efficient manner. They can leverage features such as blockchain tokens for payments, smart contracts for automated transactions, privacy layers and data protection techniques. Additionally, the expertise of a Blockchain Developer will ensure the project complies with industry standards, ensuring secure data and validation.
Here's some projects that our expert Blockchain Developer made real:
At Freelancer.com customers have posted amazing projects covering a variety of use cases related to blockchain utilising the Freelancer verified experts. With help from professionals on Freelancer.com customers can create unique projects addressing their business needs with safety, security and legality in mind. Rock your blockchain project today and hire an expert Blockchain Developer on Freelancer.com now!
Von 84,518 Bewertungen, bewerten Kunden unsere Blockchain Developers 4.82 von 5 Sternen.Blockchain, is a technology that encompasses digital records or information, referred to as “blocks”, that are linked together securely and share the same network. This distributed ledger technology is the backbone of a new wave of innovation being implemented into our lives, with new disruptive applications and solutions seen in a growing number of industries. Clients may hire a Blockchain Developer to harness this power and build a secure digital platform tailored to their business needs.
A Blockchain Developer can create unique solutions leveraging blockchain technology to securely store, access, mine and distribute data in an efficient manner. They can leverage features such as blockchain tokens for payments, smart contracts for automated transactions, privacy layers and data protection techniques. Additionally, the expertise of a Blockchain Developer will ensure the project complies with industry standards, ensuring secure data and validation.
Here's some projects that our expert Blockchain Developer made real:
At Freelancer.com customers have posted amazing projects covering a variety of use cases related to blockchain utilising the Freelancer verified experts. With help from professionals on Freelancer.com customers can create unique projects addressing their business needs with safety, security and legality in mind. Rock your blockchain project today and hire an expert Blockchain Developer on Freelancer.com now!
Von 84,518 Bewertungen, bewerten Kunden unsere Blockchain Developers 4.82 von 5 Sternen.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’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...
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...
hello, i'm building a social layer for polymarket but can't place an ordrer trhough i keep getting this error XHR POST [HTTP/3 400 175ms] [CLOB Client] request error {"status":400,"statusText":"","data":{"error":"invalid signature"},"config":{"transitional":{"silentJSONParsing":true,"forcedJSONParsing":true,"clarifyTimeoutError":false},"adapter":["xhr","http","fetch"],"transformRequest":[null],"transformResponse":[null],"timeout":0,"xsrfCookieName":"XSRF-TOKEN","xsrfHeaderName":"X-XSRF-TOKEN","maxContentLength":-1,"maxBodyLength":-1,"...
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 web-based crypto cricket fantasy game. The game should include: - Player selection and management - Live scoring updates - Crypto wallet integration Ideal skills and experience: - Game development experience, especially in fantasy sports - Strong knowledge of cryptocurrency and blockchain technology - Proficient in web development - Experience with real-time data integration for live updates Please provide detailed project proposals.
Hi I will share the details with the shortlisted candidates. Thanks
I’m searching for production-ready AI agents I can roll out across several verticals—specifically Healthcare, Real Estate, E-commerce, Blockchain, Crypto, and Social Media. Each solution must already be live somewhere so I can see it operating in real time before we move forward. The core requirements are straightforward: the agent needs to run in a browser, accept its own knowledge base or document set for context, and ship with source code plus clear documentation. I’m also expecting help getting the code stood up in a SaaS or on-prem environment. I’m flexible on architecture; whether you built it around OpenAI, Claude, Llama, FastAPI, Node.js, Pinecone, FAISS, or Weaviate doesn’t matter as long as it performs reliably at scale. To keep things simple, here...
I’m searching for production-ready AI agents I can roll out across several verticals—specifically Healthcare, Real Estate, E-commerce, Blockchain, Crypto, and Social Media. Each solution must already be live somewhere so I can see it operating in real time before we move forward. The core requirements are straightforward: the agent needs to run in a browser, accept its own knowledge base or document set for context, and ship with source code plus clear documentation. I’m also expecting help getting the code stood up in a SaaS or on-prem environment. I’m flexible on architecture; whether you built it around OpenAI, Claude, Llama, FastAPI, Node.js, Pinecone, FAISS, or Weaviate doesn’t matter as long as it performs reliably at scale. To keep things simple, here...
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...
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...
We are looking for an experienced and reliable lead generation specialist with a strong understanding of the cryptocurrency and blockchain space. Your primary responsibility will be sourcing high-quality, targeted crypto leads based on defined criteria. This may include (but is not limited to): • Identifying potential investors, traders, or crypto-interested users • Sourcing business leads within the blockchain / Web3 ecosystem • Collecting accurate contact details and relevant data • Ensuring leads are verified and up-to-date Requirements: • Proven experience in lead generation (preferably in crypto / blockchain niche) • Strong research skills and attention to detail • Ability to deliver accurate, high-quality data • Familiarity with crypt...
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 am in the middle of financial-remedy proceedings and have been appointed to instruct a single joint expert. My ex-partner has disclosed a series of public keys and wallet addresses; however, I still need a clear, defensible picture of exactly how much cryptocurrency he currently holds and through how many wallets. The work centres on three core blockchains—Bitcoin, Ethereum and Ripple—but there may be additional tokens mixed in, so flexibility to widen the net is essential. I can supply every public key and wallet address already disclosed, and I can request anything else you identify as relevant. Your task is to trace those identifiers on-chain, calculate the present balances, and compile a concise report that can stand up to court scrutiny. Chain-analysis platforms such ...
I want to launch a non-custodial crypto wallet that covers the essentials from day one. Users must be able to send and receive coins or tokens, browse a complete transaction history, and restore access at any time through a secure backup flow (seed phrase or encrypted file). The first release targets Android and a browser-based version. Feel free to use Kotlin, Flutter, React Native, or similar for mobile, and React/ (or comparable) for the web client, so long as the codebase is clean and well-documented. Security should follow a solid “standard” approach: client-side key generation, AES-256 encrypted private keys, optional PIN/biometric unlock, HTTPS everywhere, and no server-side custody. Compliance with common audits or libraries (e.g., WalletConnect, ) is welcome but not...
Project Goal Build a mobile-first digital payments app that allows users to send, store, convert, and spend crypto-backed USD with extreme simplicity, comparable to Zelle or Venmo — while crypto remains largely invisible to the user. Core Principle: “It should feel like a normal money app, powered by crypto in the background.” ⸻ Target Platforms • iOS • Android • Backend server • Admin dashboard (web) ⸻ Core MVP Functionality 1. User Authentication Required: • Phone number signup • SMS verification • Optional email backup • PIN or Face ID login • Secure session management System must: • Prevent duplicate accounts • Securely encrypt user credentials ⸻ 2. Automatic Wallet Creation Upon signup, the...
URGENT: Payment will be done later with a separate contract to make the payment after the job is done due to a funding problem and will be paid through this platform, the freelancers you will hire will be paid in crypto. We need a TA Generalist with main talent for acquisition, you need to identify who we need and also why by spotting the best talent for a Memecoin Project Web3 project. We wanna be successful I would consider 10m market cap a success if not higher, we need to launch to market in the shortest time possible. You should have knowledge DeFi ecosystem and HR tools like LinkedIn Recruiter.
I want to demonstrate provable data consistency across a geographically distributed Hyperledger Fabric network by persisting the blockchain ledger in CockroachDB instead of the default back-end. The work centres on two Fabric layers: chaincode and the ledger itself. Chaincode reads and writes must be routed so that every block committed by a peer is durably stored in CockroachDB, and peers must replay that data with no divergence even under node failure or network partitions. The scope includes mapping Fabric’s block and state data structures to a CockroachDB schema, wiring the peer so that commit and endorsement steps call the database seamlessly, and validating the design with a small multi-region testnet. CockroachDB will act strictly as the ledger store; MSP and other services r...
I am developing an end-to-end platform that pulls live claim-related data from Revit models, runs it through a FIDIC rules engine, and then immutably stores and certifies every step on Hyperledger Fabric. The objective is clear: the moment a potential claim is flagged in the BIM environment, it should be automatically registered, classified, validated against the relevant FIDIC clauses, and published to an auditable ledger—with a web dashboard showing the entire trail in real time. Scope of work • BIM connector: a service that extracts the necessary objects, properties, and metadata directly from Revit (IFC compatibility is a plus) and hands them to the API. • Integration backend (API): a lightweight, well-documented REST/GraphQL layer focused on automated workflows&md...
I’m working with BitcoinPHP and I need a concise, well-commented snippet (or small class) that can derive and export a fully valid Bech32 (native SegWit) address from a given public key or HD-path.
I have a new Web3 idea ready to move from concept to code and I’m seeking an experienced blockchain developer to guide and build the entire solution with me. Because the project is still early-stage, I’m open on the specific chain, tech stack, and even the exact feature set—we’ll define those details together during an initial discovery call. What I do know is that the end product will rely on smart contracts, a dApp front end, and secure wallet interaction, so familiarity with Solidity or similar contract languages, , and modern front-end frameworks is essential. Here’s how I’d like to structure our collaboration: – First, a short technical workshop where you assess my concept, recommend an appropriate blockchain (Ethereum, BSC, Polkadot, or ...
I’m preparing to launch a brand-new BEP-20 asset on the BNB Smart Chain that mirrors the technical discipline of USDT while remaining an entirely separate token. Here’s what I need from you: • A clean, audited-style smart contract written in Solidity that compiles under the latest stable version, adheres strictly to the BEP-20 interface, and defaults to 18 decimals. • Flexible placeholders for the name, symbol and total supply; I will confirm those values right before deployment. • Owner-controlled mint and burn functions so I can expand or contract supply as required. • A blacklist / whitelist mechanism to freeze or allow specific addresses when necessary. (Transfer-pause logic is nice to have, so feel free to wire it in behind a boolean flag, but ...
If you want to stay competitive in 2021, you need a high quality website. Learn how to hire the best possible web developer for your business fast.
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