Umer A.

Blockchain and Web3 developer building the application layer of crypto, fintech and payment products. I design and ship the dApp front-ends, Web3 integrations, backend APIs, secure transaction flows and financial software that turn a blockchain idea into a product people can actually use. Most blockchain products don't break on-chain. They break around it: payment flows that confuse users, transaction records that don't reconcile, APIs that stall under real traffic, and admin tools nobody can operate. That layer of blockchain development is where I work, backed by 8+ years of software engineering and hands-on payment integration. ━━━━━━━━━━━━━━━━━━━━ 🔗 BLOCKCHAIN & WEB3 DEVELOPMENT - dApp development: React, Next.js and TypeScript front-ends for decentralized applications, token platforms, NFT marketplaces and DeFi dashboards - Web3 integration: connecting blockchain applications to your existing product, user accounts, backend services and payment systems - Smart contract integration: I build the interfaces, APIs and data layer around your smart contracts, and work alongside your Solidity team on contract development and audits - Web3 backends: Node.js, NestJS and FastAPI services for transaction records, user management, admin panels and blockchain data reporting ◈ CRYPTO & DIGITAL ASSET PLATFORMS - Crypto dashboards and digital asset views: transaction history, analytics, reporting and admin tooling - Crypto payment integration: bringing crypto and blockchain payment flows into existing checkout, billing and subscription systems - Blockchain + AI: AI-driven analytics, LLM features and workflow automation inside Web3, crypto and fintech products ▣ FINTECH, PAYMENTS & FINANCIAL SOFTWARE - Payment gateway integration and payment processing: checkout, subscription billing, webhooks, transaction handling and payment status tracking - Mobile payment functionality for web and React Native apps - Financial software and transaction systems: ledgers, transaction records, reporting, analytics dashboards and admin panels - Financial SaaS platforms: multi-tenant architecture, subscription-ready billing, role-based access control 🛡️ SECURITY & API INTEGRATION - Blockchain and Web3 security at the application level: server-side validation, protected secrets and API keys, least-privilege access and traceable transaction logs - Authentication and access control: JWT/OAuth and role-based permissions for crypto, payment and admin dashboards - API development and API integration: secure REST and GraphQL services, payment APIs and third-party data integrations ━━━━━━━━━━━━━━━━━━━━ WORK I CAN POINT TO - Payment module and TCG card-scanner integration for a trading-card marketplace, web and React Native (Upwork, 5.0) - Full-stack development on the same marketplace platform (Upwork, 5.0) - Buslane: real-time transit app with smart routing and in-app payments (FastAPI, Next.js, Google Cloud) - DealAI: AI business platform with CRM, sales workflows and automation (React, Next.js) - AI marketing web app with builder, CRM, analytics and AI design modules (React, TypeScript, FastAPI) - AI consultation platform with speech-to-text and NLP ⚙️ STACK Frontend: React, Next.js, TypeScript, Angular, React Native Backend: Node.js, NestJS, FastAPI, Python, REST, GraphQL Data: PostgreSQL, Supabase, MongoDB Cloud: AWS, Google Cloud, Vercel, Docker, CI/CD AI: OpenAI/ChatGPT integration, NLP, speech-to-text, automation HOW I WORK Senior Full Stack Engineer since 2018. I scope work into clear milestones, send regular updates, write documented code your team can extend, and treat every transaction and payment flow as security-critical. Building a blockchain application, a dApp, a Web3 platform, a crypto payment flow or a fintech product? Send me a short description and I'll come back with a clear technical approach and next steps.