Blockchain EVM | Crypto Exchange (CEX/DEX) | Solana | Web2 Full-Stack - 8+ Years Mayur Antre Full Stack Developer For 8+ years, I’ve been building production-grade Web2 platforms, Web3 protocols, crypto exchange systems, trading bots, and automation pipelines. I care about speed, safety, and scale—the kind that holds up under real traffic and real money. If you want a partner who can handle architecture + execution, you’re in the right place. 💻 Web2 Engineering (Backend + Frontend + Infra) Backend & Architecture - Node.js (Express/NestJS), Java (Spring Boot) - REST / GraphQL APIs, microservices, WebSockets (realtime) - Auth & security: JWT/OAuth, RBAC, 2FA, rate limiting, audit logs - Job queues & workers for heavy tasks + scheduled processing Data & Storage - PostgreSQL, MySQL, MongoDB, Redis, DynamoDB - caching strategy, indexing, query tuning, data modeling - reporting pipelines, exports, analytics-ready schemas Frontend - React / Next.js / Angular, TypeScript - admin panels, dashboards, role-based UI, responsive design Infrastructure - Docker, CI/CD, Linux deployments - AWS/GCP (compute, storage, databases, monitoring) - observability: logs, metrics, alerts, uptime monitoring ✅ Typical deliveries: SaaS apps, admin systems, payment/subscription flows, realtime dashboards, API platforms. 🤖 Trading Bots & Execution Systems (CEX + DEX) - Arbitrage bots (multi-exchange + on-chain/off-chain routes) - Sniper/launch bots (liquidity & pair detection, trigger-based execution) - Indicator bots (RSI/MACD/grid/DCA + custom strategies) - Market-making style logic (spread control, inventory rules, risk limits) - Backtesting + simulation environment (paper/live modes) - Monitoring dashboards + alerting (Telegram/Discord/email) - Secure key handling patterns + fail-safe execution workflows ✅ Integrations: centralized exchange APIs + DEX swaps/routers + custom pricing feeds. 🕸 Automation, Scraping & Data Pipelines - Browser automation with Playwright/Puppeteer - rotating proxies, anti-block patterns, session handling - price tracking & alerts, lead collection, data normalization - schedulers + workers + storage (DB/files) for continuous runs - API extraction / parsing for public endpoints (where permitted) ✅ Built for stability: retries, throttling, logging, crash recovery. 🔗 Blockchain & Smart Contract Development Smart Contracts - Solidity (EVM) + Rust (Solana) - Hardhat / Foundry, Anchor - Token standards: ERC20/BEP20, ERC721/1155, vesting, claims, airdrops - role-based permissions, upgrade patterns (when required), gas optimization - test suites + deployment scripts + verification support DeFi / On-chain Systems - staking & rewards (fixed/variable emissions, multipliers, lockups) - liquidity + fee logic, treasury distribution, revenue share mechanics - vault-like systems, farming flows, protocol integrations (project-specific) - NFT drops: allowlists, phases, reveal, metadata strategy Exchange Builds - DEX: AMM-style features, routing support, analytics + admin controls - CEX support: wallet module architecture, operational dashboards, integrations ✅ Chains: Ethereum, BSC, Polygon, Avalanche, Solana, Tron. 🛡 How I Work (Quality & Security) - clear scope → milestone plan → staged delivery - test coverage + edge-case handling - security review mindset from day one (not “after finishing”) - documentation so your team can maintain and scale confidently ✅ Why Clients Choose Me - Founder-led communication (direct, fast, accountable) - Full-stack coverage (contracts + backend + frontend + deployment) - Practical engineering (built for uptime, monitoring, and scaling) - On-time delivery with transparent progress updates 📩 Message Me With - What you’re building (Web2/Web3/bot/automation) - Chain(s) + target users - Must-have features - Timeline + budget range I’ll respond with a clear implementation plan and the best approach to ship safely.

With over 5 years of experience in the international startup ecosystem, I specialize in building robust, scalable products from the ground up. I am a language and framework agnostic engineer who prioritizes using the right tool for the job without ever compromising on technical integrity. I began my career in 2019 translating high-level AI research papers into functional products. Since then, I have architected facial recognition systems, image processing pipelines, and LLM-based regulatory software for fintech startups across Europe and Asia. Since the early 2020s, I have been a core contributor to the DeFi space. I started out designing yield farming algorithms and loan regulatory software for Nord Finance. I joined BankX in late 2021 as the lead developer back when it was still just a white paper and a set of technical requirements. I built the entire protocol ecosystem from scratch and successfully navigated multiple audits from audit firms like CoinFabrik and Immunefi. The protocol is currently live on 8 different chains including PulseChain. In August 2024, I co-founded CtrlBit- A SaaS infrastructure platform for Mikrotik network management. The platform is live and handles centralized monitoring, zero-touch provisioning and secure remote access for global ISPs and enterprises at a fraction of the price. I don't just write code; I build sustainable businesses. I am financially literate, MTCNA certified and experienced in bridging the gap between complex engineering and market-ready solutions. I am currently on the lookout for innovative projects that require high-level technical leadership. Message me for a consultation. I am generally available during PST and UTC business hours.

Hi, I'm Japhet, an experienced senior full-stack developer from the Philippines specializing in React.js, Next.js, Node.js, Python, Go, AWS, GCP, AI model integration (including Chat GPT), and blockchain (smart contracts and DApps), known for creating seamless web and mobile applications with robust backends and responsive frontends to drive business growth. 💻 Technical Expertise ⭐ Frontend: React.js, JavaScript, TypeScript, HTML5, CSS/SASS, Bootstrap ⭐ UI/UX: Figma, Adobe XD ⭐ Backend: Node.js, Next.js, Express.js, PHP, Laravel, Python, Go ⭐ APIs: RESTful, GraphQL ⭐ Database: MySQL, PostgreSQL, MongoDB, Firebase ⭐ Blockchain: Smart Contracts, DApps, Ethereum, Solana, TON, Solidity, Web3.js ⭐ DevOps: AWS, Digital Ocean, Firebase, Vercel, Docker, Kubernetes ⭐ Specialized Integrations: Payment Gateways (Stripe, Razorpay, Paytm, Apple Pay), Communication APIs (Twilio, SendGrid, MessageBird) ⭐ Project Tools: GitHub, GitLab, Bitbucket, VS Code, Jira, Trello, ClickUp 💼 𝖶𝗁𝗒 𝖯𝖺𝗋𝗍𝗇𝖾𝗋 𝖶𝗂𝗍𝗁 𝖬𝖾 𝖺𝗌 𝖺 𝖥𝗎𝗅𝗅 𝖲𝗍𝖺𝖼𝗄 𝖣𝖾𝗏𝖾𝗅𝗈𝗉𝖾𝗋? 🔗𝖢𝗅𝖾𝖺𝗋 𝖢𝗈𝗆𝗆𝗎𝗇𝗂𝖼𝖺𝗍𝗂𝗈𝗇 𝗍𝗁𝗋𝗈𝗎𝗀𝗁𝗈𝗎𝗍 𝗍𝗁𝖾 𝗉𝗋𝗈𝗃𝖾𝖼𝗍 🔗𝖢𝗈𝗆𝗆𝗂𝗍𝗆𝖾𝗇𝗍 𝗍𝗈 𝖼𝗅𝖾𝖺𝗇, 𝗌𝖼𝖺𝗅𝖺𝖻𝗅𝖾 𝖼𝗈𝖽𝖾 𝖺𝗇𝖽 𝗁𝗂𝗀𝗁 𝗌𝗍𝖺𝗇𝖽𝖺𝗋𝖽𝗌 🔗𝖥𝗅𝖾𝗑𝗂𝖻𝗂𝗅𝗂𝗍𝗒 𝗍𝗈 𝗆𝖾𝖾𝗍 𝖽𝖾𝖺𝖽𝗅𝗂𝗇𝖾𝗌 𝖺𝗇𝖽 𝖺𝖽𝖺𝗉𝗍 𝗍𝗈 𝗉𝗋𝗈𝗃𝖾𝖼𝗍 𝗇𝖾𝖾𝖽𝗌 💪 Key strengths to ensure success: ✅ Mastery in NestJs, NextJs, and ReactJs development, alongside proficiency in other modern technologies. ✅ Outstanding communication skills and a strong sense of ownership for the work delivered. ✅ Comprehensive understanding of business dynamics, from conceptualizing POCs and MVPs to testing hypotheses, to crafting well-tested, maintainable applications that delight customers. ✅ Adaptable and responsive, effectively addressing challenges and adjusting to project requirements as needed. ✅ Committed to continuous learning and staying up-to-date with industry trends, ensuring cutting-edge solutions are employed in every project. 🚀 𝖧𝗈𝗐 𝖨 𝖬𝖺𝗄𝖾 𝖺 𝖣𝗂𝖿𝖿𝖾𝗋𝖾𝗇𝖼𝖾 🌐𝖲𝗒𝗌𝗍𝖾𝗆𝖺𝗍𝗂𝖼 𝖠𝗉𝗉𝗋𝗈𝖺𝖼𝗁 𝖿𝗋𝗈𝗆 𝗉𝗅𝖺𝗇𝗇𝗂𝗇𝗀 𝗍𝗈 𝖽𝖾𝗉𝗅𝗈𝗒𝗆𝖾𝗇𝗍 🌐𝖲𝖼𝖺𝗅𝖺𝖻𝗅𝖾 𝖲𝗈𝗅𝗎𝗍𝗂𝗈𝗇𝗌 𝖿𝗈𝗋 𝖿𝗎𝗍𝗎𝗋𝖾 𝗀𝗋𝗈𝗐𝗍𝗁 🌐𝖢𝗈𝗅𝗅𝖺𝖻𝗈𝗋𝖺𝗍𝗂𝗏𝖾 𝗆𝗂𝗇𝖽𝗌𝖾𝗍, 𝗈𝖿𝖿𝖾𝗋𝗂𝗇𝗀 𝗉𝗋𝗈𝖺𝖼𝗍𝗂𝗏𝖾 𝖿𝖾𝖾𝖽𝖻𝖺𝖼𝗄 🌐𝖱𝖾𝗌𝗎𝗅𝗍𝗌-𝖮𝗋𝗂𝖾𝗇𝗍𝖾𝖽, 𝖾𝗇𝗌𝗎𝗋𝗂𝗇𝗀 𝗏𝖺𝗅𝗎𝖾 𝗐𝗂𝗍𝗁 𝖾𝗏𝖾𝗋𝗒 𝖿𝖾𝖺𝗍𝗎𝗋𝖾 📩🚀 Ready to elevate your project to new heights? Don't hesitate – send a direct message or invite to the project for an exceptional experience! Let's make your vision a reality together! Keywords: #FullStackDevelopment #FullStackExpert #FullStackSolutions #ReactDeveloper #NodeJSDeveloper #PHPDeveloper #PythonDevelopment #GoDevelopment #AIIntegration #ChatGPTIntegration #BlockchainDevelopment #SmartContracts #DApps #SolidityExpert #Ethereum #Web3 #NestJsDevelopment #NextJsExpert #ReactJsApps #NodeJSSolutions #FullStackCoding #MERNStack #MEANStack #DevOpsEngineer #AWS #GCP #Docker #Kubernetes #CI/CD #Automation #RESTfulAPI #GraphQLDevelopment #CustomAPI #APIIntegration #WebDevelopment #MobileAppDevelopment #ResponsiveDesign #UI/UXDesign #Figma #AdobeXD #APIAutomation #CloudServices #ServerlessArchitectures #Microservices #Lambdas #CloudFormation #ScalableWebApps #ModernWebSolutions #BackendIntegration #SiteAvailability #PerformanceOptimization #SecurityPractices #PaymentGatewayIntegration #Stripe #Razorpay #ApplePay #TwilioAPI #SendGridAPI #CommunicationAPIs #VersionControl #GitHub #GitLab #Bitbucket #CollaborationTools #ProjectManagement #Jira #Trello #VSCode

Hybrid applications are the future—and Flutter stands at the very top as the most powerful choice for businesses that want speed, beauty, and cross-platform consistency. I help brands and founders bring these ideas to life. I’m a Full-Stack Developer, mobile apps enthusiast, and Rust backend engineer with a passion for building experiences that feel effortless, polished, and reliable. With 6+ years of hands-on experience, I specialize in crafting high-performance digital products from the ground up. On the mobile side, I deliver smooth, intuitive apps using: Flutter (my top hybrid framework of choice) React Native Native Android (Kotlin) & Native iOS (Swift) On the backend, I build extremely fast, secure, and scalable APIs powered by Rust, using modern frameworks such as: Actix-Web — blazing-fast, production-grade web services Tokio, SeaORM, Serde, JWT, and other high-performance Rust crates Microservices, async systems, and highly optimized architectures I transform client requirements into solutions that are: Beautiful Functional Performant Reliable in production I don’t just code—I deliver experiences. Getting things done, the right way.

My work has helped generate over $25 million in revenue across more than 70 projects. I’m Karim, a software expert based in the Netherlands. I help founders build successful products with speed and efficiency in mind. ★ RESULTS - Helped clients generate 25 million dollars in revenue - Launched multiple client products exceeding 100.000 users - Worked with 10+ seven figure entrepreneurs as their product partner ★ WHAT I DO BEST - SaaS Products I design and build scalable SaaS platforms with subscription billing, user management, integrations, and analytics. - AI Products I deliver AI-driven products integrating with state-of-the-art models from GPT-powered chat apps to voice synthesis and image generation platforms. - Internal Platforms I create secure, efficient platforms for managing company data, client-facing apps and tools that automate lead generation, email campaigns, reporting and CRMs. - Chrome Extensions I build custom Chrome extensions that enhance productivity, automate workflows, and integrate directly with SaaS platforms. ★ HOW I WORK - I start with an advisory call to understand your goals - I map out a clear plan with real results - I build clean, secure code and help launch your product - I stay on to support, scale, and improve it ★ LET’S TALK Have a software idea you want to launch? Message me “BOOK” for a free call. I’ll help you shape the idea, plan your next steps, and start building.

Hey, I'm Raoul👋 I’m a freelance quantitative developer with a strong background in building pricing and risk models for derivatives, automated trading algorithms and backtesting frameworks across multiple asset classes. With over a decade of experience in the financial industry and technology sector, I’ve worked with major institutions like ING, ABN AMRO, Credit Suisse, and Santander, helping them develop robust and scalable quantitative solutions. My expertise includes: ✅ Quantitative Development – Designing and implementing complex financial models for pricing, risk management, automated trading and high performance data pipelines. ✅ Asset Classes – Equities, Interest Rates, Forex, Commodities, and Crypto. ✅ Software Development – Python, Rust, C++, Git, Docker, Kubernetes. ✅ Cloud Deployment – GCP, AWS, Azure. ✅ API & WebSocket Frameworks – Extensive experience integrating financial data sources and real-time market feeds. ✅ Market Data Providers – Alpaca, Alpha Vantage, IEX, Twelve Data, Yahoo Finance. I take pride in writing clean, well-tested and documented efficient code, ensuring high-quality results that meet regulatory and business requirements. Whether you need custom trading algorithms or complex models developed, a backtesting frameworks, real-time market data integration, or a custom risk engine, I can help bring your quantitative ideas to life. If you're looking for a skilled and reliable quant developer, let’s connect! Cheers, Raoul

I’m a software engineer with 10 years of experience building and delivering high-impact products. With a degree in Computer Science from Stanford University, specializing in artificial intelligence, I’ve had the opportunity to work across multiple industries, from AI systems and financial platforms to cloud infrastructure and networked applications. I specialize in architecting efficient, scalable solutions—whether it's launching mobile apps, designing complex social platforms, or leading the development of cutting-edge blockchain technologies. I excel at translating complex requirements into seamless, high-performance systems, ensuring the end product is robust, easy to maintain, and designed to meet specific business objectives. What sets me apart is my product-minded approach to development. I’m not just a developer—I lead teams, manage projects end-to-end, and ensure that every feature aligns with business goals. I’m independent and entrepreneurial, having built and fundraised for my startup, MetaJamz. This experience helps me craft solutions that are technically sound and primed for growth, giving clients an edge in their markets. Let’s collaborate, and I’ll bring this same level of passion and expertise to your project.

As a Senior Full Stack Developer and Cloud Engineer, I specialize in creating scalable solutions that drive performance and efficiency. My expertise spans AWS, ReactJS, NodeJS, Python, and GoLang, with a focus on cloud architecture, AI integration, and mobile development. At GuardianVets, I developed a custom AI Receptionist that improved live agent efficiency by 50% while enhancing infrastructure redundancy by 75%. At Leading Path Consulting, I boosted web application performance by 33% and streamlined data pipelines, increasing deliverable speed by 42%. My experience also includes leading mobile app development at Working America, using Flutter and GraphQL to optimize operations. I thrive on solving complex challenges with innovative, data-driven solutions, and I’m passionate about leveraging my skills to deliver high-impact, efficient systems.

My experience integrates data science and systems development, with emphasis in finance and trading. I handle predictive model engineering, building workflows with machine learning approaches. Reliable solutions as well as performant and maintainable systems are my concerns. Got a project in mind? Let's talk. - Systems for algorithmic trading and business intelligence. - Products: libraries, command line tools, web services, data connectors. - Services: architecture design, implementation, maintenance.

I've 10+ years of extensive experience in building robustand scalable applications that drive business growth. I combine deep technical expertise with a solutions-oriented mindset to deliver high-quality software that exceeds client expectations. Core Competencies: - Backend Development: Python (Django, Flask, FastAPI), RESTful APIs, GraphQL - Database Design: PostgreSQL, MongoDB, MySQL, Redis - Cloud Services: AWS, Google Cloud Platform, Azure - AI/ML Integration: OpenAI/Anthropic APIs, Hugging Face, TensorFlow, custom ML solutions - System Architecture: Microservices, containerization (Docker), Kubernetes, CI/CD pipelines - API Integration: Payment gateways, social media, third-party services What Sets Me Apart: - End-to-end project ownership from requirements gathering to deployment - Strong focus on writing clean, maintainable, and well-documented code - Experience with both monolithic and microservices architectures - Proven track record of delivering projects on time and within budget - Excellent communication skills and responsive collaboration I prioritize writing efficient, secure, and scalable code while maintaining clear communication throughout the development process. Let's discuss how I can help bring your project to life with modern Python based solutions.