Hire Vetted Web Application Engineers at Upstaff - Page 3

• Backend & Protocol Engineering: 7+ years building large-scale, high-performance consensus-layer systems in Go and C++.
• Scalable Data Architecture: Architected high-load EVM indexers, delivering sub-second analytics over 100M+ rows with real-time streaming via REST, gRPC, and SSE.
• Cryptography: Developed ZK circuits (gnark) and secure distributed signing nodes (MPC) using advanced primitives like BLS and ECDSA.
• Network Optimization: Optimized consensus protocols (CasperFFG, LMD-GHOST) and libp2p networking, scaling production networks with up to $2B in market cap.
• Systems Foundation: B.Sc. in Informatics & Applied Mathematics with deep expertise in LLVM and compiler-level optimization.

• Proficient in TypeScript, JavaScript, Python, SQL (PostgreSQL/Plpg SQL), with extensive backend and full-stack development experience using Supabase, PostgreSQL, and REST APIs.
• Developed and maintained complex systems including travel pricing platforms, contract management, and crypto investment dashboards, demonstrating strong database schema design and server-side logic implementation.
• Expertise in bot development with Twilio and WhatsApp Business API, and Python Telegram bots featuring automated scheduling and persistence.
• Skilled in frontend frameworks Vue.js, React, Next.js, and responsive UI design, with deployment experience on Vercel
• Applied SEO optimization

• 6+ years in enterprise web application development with expertise in Python (FastAPI), Angular, and React.js.
• Proficient in designing and optimizing REST APIs, implementing OAuth 2.0, JWT, SSO, and enhancing Core Web Vitals for performance.
• Hands-on experience with AWS EC2, SSR, Pub/Sub, and integrating backend services with frontend React applications.
• Strong background in Computer Science (B.Tech) and Agile methodologies, contributing to scalable and maintainable software solutions.
• Demonstrated ability in backend FastAPI development and production support for client projects, ensuring robust authentication and API performance.

• Software engineer with 4+ years in cross-platform mobile and front-end development, specializing in React, React Native, and Flutter.
• Proficient in state management (Redux Toolkit, BLoC, Redux Saga), API integration, CI/CD pipelines, and performance optimization.
• Experienced in Agile methodologies, leading teams, mentoring developers, and delivering scalable applications for Android and iOS.
• Developed complex apps featuring real-time communication (Socket.IO), multi-authentication, payment integration (Stripe), and cloud services (Firebase, AWS Amplify).
• Strong background in computer science engineering , applying clean architecture and modular design patterns in production projects.

• Senior Software Developer & Team Lead with 10+ years in backend architecture, REST API design, and cloud infrastructure using Node.js, Python, Laravel, and AWS services including hands-on experience in database design (MySQL, PostgreSQL, MongoDB) and modern software development practices.
• Expertise in AI-powered applications, specializing in RAG systems with LangChain, OpenAI APIs, Ollama, Pinecone, and Qdrant vector databases.
• Proven track record leading scalable web and mobile app projects, including AI-driven recommendation engines and intelligent notification systems.
• Strong command of microservices, serverless architectures, and deployment automation on AWS (EC2, ECS, Lambda, API Gateway).

• Engineer with 5+ years in frontend development, specializing in AI-powered web applications, LLM integrations, and MCP-based workflows.
• Expertise in TypeScript, React, and backend technologies including Node.js, NestJS, REST, and GraphQL APIs.
• Designed and led frontend architecture for complex financial platforms, implementing real-time analytics, multi-provider authentication, and third-party integrations.
• Proficient in AI tooling such as Claude Agent SDK, OpenAI API, and prompt engineering, delivering AI-enhanced automation and intelligent features.

Experienced in Agile methodologies, scalable component systems, performance optimization, and cross-functional collaboration in fintech, Web3 ect.

• Over 5 years of experience in front-end and full-stack development with deep expertise in Angular (2-21), NgRx, RxJS, and state management for scalable web applications.
• Proficient in modern JavaScript/TypeScript frameworks (React, Redux, Node.js, Nest.js), hands-on experience building complex applications integrating blockchain (Terra.js) and 3D visualizations (Three.js).
• Skilled in RESTful and GraphQL API design, MongoDB, PostgreSQL, and CI/CD pipelines using Jenkins and Bitbucket.
• Delivered high-impact projects such as insurance web tools, crypto exchange platforms, and real-time chat apps, demonstrating strong architectural design, custom authentication, and performance optimization.

• Senior Web Designer with 15+ years in front-end development, specializing in HTML5, Bootstrap 4&5, CSS/SCSS, Angular Material Design, React.js, WordPress, and Shopify development.
• Proven expertise in full HTML development lifecycle for dynamic web projects, integrating responsive design and UI/UX best practices.
• Skilled in design tools including Photoshop, Adobe XD, Figma, and Adobe Illustrator, enhancing creative and technical project delivery.
• Strong background in project management and client relations, delivering high-impact web solutions for diverse industries.
• Experience with version control (GitHub) and modern web frameworks, ensuring maintainable and scalable codebases.

• Frontend Software Engineer with 3+ years of experience specializing in React.js, Next.js, and modern JavaScript (ES6+), delivering scalable, high-performance web applications.
• Proven expertise in AI integration, including LLM API (Google Gemini, OpenAI) and chatbot development, demonstrated through leading AI-driven SaaS platforms like Cheaper.com.
• Strong background in full SDLC, API orchestration (REST, GraphQL), and performance optimization, achieving up to 35% load speed improvements and 90+ Lighthouse scores.
• Computer Science degree holder with hands-on experience in backend technologies (Node.js, Django REST), database management (PostgreSQL, MySQL), and CI/CD pipelines (GitHub Actions).

• Full Stack Developer with 4+ years of experience architecting scalable web applications using React.js, Next.js, Node.js, and Python frameworks (FastAPI, Django), specializing in AI integration and cloud-native solutions.
• Proficient in designing and optimizing RESTful and GraphQL APIs, microservices, and serverless architectures with expertise in PostgreSQL, MongoDB, Redis, and vector databases (Pinecone, Weaviate).
• Skilled in DevOps practices including CI/CD pipelines, Docker, Kubernetes, AWS services, and automated testing (Jest, Cypress, Playwright) to ensure robust, secure deployments.

Proficient in backend and full-stack development using Python, Go, Java, TypeScript, and PostgreSQL, with hands-on experience building high-throughput API gateways and event-driven microservices.

• 24 years of expertise in full-stack development and enterprise architecture, specializing in Java, SpringBoot, Angular, and microservices.
• Architected high-performance systems including SOLR-based enterprise search
• Proficient in blockchain development with Rust/TypeScript for Solana, building high-frequency trading bots and automation tools.
• Skilled in containerization, Kubernetes orchestration, and CI/CD pipelines with Jenkins and Docker to enhance deployment reliability.
• Experienced in designing scalable cloud-native architectures integrating OAuth2, Keycloak, and advanced middleware for secure authentication and seamless system integration.

• Frontend Developer with 1+ year of experience building SaaS platforms and dashboards using React, Next.js, TypeScript, and Tailwind CSS.
• Skilled in designing PostgreSQL schemas and REST APIs with FastAPI and Prisma ORM, enabling full-stack feature delivery.
• Implemented advanced state management using React Query, Zustand, and Redux Toolkit to optimize data flow and UI responsiveness.
• Developed secure authentication systems with NextAuth.js, including OAuth, email verification, and protected routes.
• Experienced in microservices architecture, real-time data pipelines, and cloud storage integration, demonstrated in projects using Kafka, Docker, and Google Cloud Storage.

• Experienced MERN Stack Developer with 7+ years in designing and implementing scalable RESTful APIs, secure authentication systems (JWT, OAuth), and real-time features using Socket.io.
• Proficient in MongoDB schema optimization, query tuning, and building multi-vendor SaaS platforms, LMS, and AI-integrated applications.
• Skilled in full SDLC, agile methodologies, CI/CD pipelines, Docker, and cloud deployments (AWS EC2, S3, Lambda) ensuring high availability and performance.
• Strong expertise in frontend technologies including React.js, Redux, Context API, and responsive design frameworks like Tailwind and Bootstrap.
• Demonstrated ability to integrate third-party payment gateways and external APIs.

• Senior Full Stack Engineer with 12+ years of experience, including 8+ years with Node.js, TypeScript, and Vue.js (Tailwind CSS)
• Specialized in microservices (NestJS), event-driven systems (Kafka, RabbitMQ), and configurable enterprise SaaS platforms
• Ensured production reliability with on-call support for high-load systems
• Skilled AWS (Lambda, VPC), Terraform, Docker, CI/CD expertise
• Experience in enterprise (healthcare) and startups (Y Combinator-level, Sixa)
• Focused on AI-driven SaaS, open to long-term collaboration; builds trading bots

• 7+ years of experience, specializing in full-stack development with React, Vue, Next.js, Node.js, NestJS, and TypeScript.
• Expertise in architecting dashboards, multi-currency payment forms, and microservices using Prisma, PostgreSQL, and MongoDB.
• Skilled in state management (Zustand, Redux, TanStack Query), real-time data handling (Socket.io, WebSockets), and performance optimization (Redis caching, code splitting).
• Background in test-driven development with Jest, React Testing Library, and Cypress, plus containerization and AWS deployment.
• Skilled in designing role-based access systems and integrating OAuth 2.0, JWT, and complex API workflows in distributed architectures.

• Full Stack Engineer with 20+ years of experience in scalable web platforms, specializing in React, TypeScript, Node.js, and cloud-native architectures (AWS, GCP, Azure).
• Expertise in designing modular frontend architectures, reusable component libraries, and backend microservices with performance optimization and high-load scalability.
• Experience integrating AI-assisted development workflows using LLM APIs and agentic coding tools.
• Background in system design, distributed systems, event-driven architecture, and secure financial/payment processing platforms with multi-provider integrations.
• Knowledge of SDLC, CI/CD automation, DevOps practices, and engineering leadership in Agile environments.

• Full Stack Engineer with 10+ years of experience delivering scalable SaaS platforms and cloud-native systems using React, TypeScript, Python, FastAPI, Django, Node.js, PostgreSQL, Redis, and AWS.
• Proven expertise in legacy system modernization, reducing API response times from 3s to under 1.8s by migrating C#/.NET services to modern microservices architectures.
• Strong background in system design, distributed systems, event-driven workflows with Kafka, Celery, and Redis, improving performance and reducing blocked API requests by 40%.
• Skilled in cross-platform development with React Native and Expo, cutting duplicated implementation by 25% while maintaining consistent UX across web and mobile.

Senior Front-End Developer (React Native mobile / React web) with 10+ years of experience. Skilled at JavaScript, TypeScript, and React. I’ve worked on various projects and have extensive expertise. I have experience developing projects from scratch through to market release.

• Backend engineer with expertise in NestJS, Node.js, and TypeScript, specializing in building secure, scalable REST APIs and auth systems
• Proven experience in Web3 integrations, smart contract auditing on Celo, and blockchain technologies including Solana, Farcaster SDK
• Skilled in container orchestration and infrastructure automation using Docker SDK, docker compose, and Caddy for zero-downtime deployments.
• Developed AI-powered platforms leveraging Google Gemini and Elasticsearch for real-time payment reconciliation and natural language query parsing into SQL.
• Strong focus on clean architecture, security best practices, and system design demonstrated through multiple end-to-end projects.

Software Developer with over 5 years of experience building scalable APIs and full-stack web applications using .NET Core and React.js. Experienced in designing efficient database solutions with MySQL and SQL Server, integrating third-party systems, and optimizing application performance. Proven track record of delivering production-ready systems for small to medium-sized businesses, with a strong emphasis on clean architecture, maintainable code, and business-driven solutions. Comfortable working in distributed teams using Git-based workflows.

• 18+ years in software engineering with expertise in C++, Qt/QML, Python, Django, Node.js, React, and AI integration using OpenAI APIs.
• Proven track record in building end-to-end production software including embedded automotive HMI, multi-tenant SaaS platforms, and AI-driven web applications.
• Led design and development of complex systems such as multi-app payroll/HRMS platforms, AI-powered recruitment automation, and supply-chain optimization backends.
• Strong background in database management (PostgreSQL, MySQL, SQL Server), cloud infrastructure (Docker, GCP Cloud Run), and REST API design.

• 18+ years in software engineering with expertise in C++, Qt/QML, Python, Django, Node.js, React, and AI integration using OpenAI APIs.
• Proven track record in building end-to-end production software including embedded automotive HMI, multi-tenant SaaS platforms, and AI-driven web applications.
• Led design and development of complex systems such as multi-app payroll/HRMS platforms, AI-powered recruitment automation, and supply-chain optimization backends.
• Strong background in database management (PostgreSQL, MySQL, SQL Server), cloud infrastructure (Docker, GCP Cloud Run), and REST API design.

• Over 4 years of experience in 1 outsourcing and 1 outstaffing company.
• For the last 3 years, I have been working on:
• updating legacy code to smth normal and usable (PHP/Laravel + Angular)
• adding new features to both app/api of e-commerce project (PHP/Laravel + Angular)
• creating a new project from scratch (Python/FastAPI + Angular)
• adding new features to the dating project (Python/FastAPI + Angular)

• Over 10 years of expertise in Ruby on Rails and PostgreSQL, specializing in scalable web applications and performance optimization.
• Proven track record in designing modular microservices and implementing automated KYC systems, enhancing verification success, and reducing manual workload.
• Extensive experience with Angular (5+ years) and React for full-stack development, delivering high-traffic social networks and CRM platforms.
• Skilled in REST/GraphQL APIs, real-time high-concurrency backend architectures, and cloud technologies including AWS and Docker.

• Proficient in full-stack development with expertise in TypeScript, React, Rust, Swift, and backend technologies including Prisma, PostgreSQL, and Bun, demonstrated through building scalable CMS, native macOS apps, and terminal tools.
• Skilled in asynchronous programming, Rust backend refactoring, and cross-platform development using Tauri and React Native, enhancing startup latency and memory usage.
• Hands-on with CI/CD pipelines, AWS deployment, and monitoring to maintain 99.9% uptime, alongside advanced automation integrating AppleScript and AI-driven transaction parsing.

• Over 6 years of experience in full-stack development, AI/ML engineering, and cloud-native architecture, with a BSc. in Computer Engineering from University of Ghana
• Proficient in JavaScript, TypeScript, Python, and frameworks like React, Next.js, Node.js, and Express, delivering scalable SaaS and mobile solutions
• Led end-to-end product development as CTO, architecting high-availability systems with 99.9% uptime and automated CI/CD pipelines on AWS and GCP
• Skilled in agile methodologies, test-driven development, and DevOps practices, optimizing cloud workflows and ensuring robust, maintainable codebases

• 7+ years of experience in full-stack development using Node.js, TypeScript, Vue.js, and PostgreSQL for scalable SaaS and AI-powered platforms.
• Skilled in database design, query optimization, and managing large-scale datasets for high-performance applications.
• Experienced in AI/LLM integration using OpenAI and Anthropic APIs for automation and intelligent workflows..
• Strong knowledge of algorithms, data structures, software architecture, and modern design patterns.
• Proficient in AWS, Azure, Docker, CI/CD, and cloud-native deployments for enterprise systems.

• 5+ years of freelance experience building custom WordPress platforms with Python/PostgreSQL backends and AI-powered features.
• Skilled in FastAPI, ETL automation (Pandas, Airflow), and serverless deployments on AWS Lambda.
• Experienced in WordPress plugin/theme development, Gutenberg blocks, performance optimization, and access control systems.
• Proficient in AI/LLM integration, prompt engineering, summarization, and OpenAI/Anthropic APIs.
• Strong frontend skills with JavaScript, DataTables, Chart.js, and remote collaboration across EST time zones.

• 5+ years of experience building custom WordPress platforms
• Expertise in building REST APIs with FastAPI, ETL pipelines using Pandas and Airflow, and deploying serverless applications on AWS Lambda.
• Skilled in developing WordPress plugins, themes, and Gutenberg blocks for subscriber-based platforms, with expertise in role-based access control and performance optimization.
• Proficient in AI/LLM integration including prompt engineering, natural-language querying, and summarization using OpenAI and Anthropic APIs.
• Strong frontend development skills with JavaScript, DataTables, and Chart.js for dynamic, interactive data visualizations and reporting interfaces.

• 10+ years of experience delivering scalable SaaS platforms and cloud-native systems using React, TypeScript, Python (FastAPI, Django), Node.js, and AWS.
• Proven expertise in legacy system modernization, reducing API response times from 3s to under 1.8s by migrating C#/.NET services to modern microservices.
• Strong in system design, distributed systems, event-driven architectures with Kafka, Celery, Redis, and performance optimization.
• Skilled in full SDLC ownership, CI/CD pipelines, containerization (Docker, Kubernetes), and infrastructure as code for reliable cloud deployments.

Senior Software Engineer with 10+ years of experience building scalable backend and data-intensive systems. Focus on clean architecture, and real-world impact