I specialize in full-stack development using the MERN stack (MongoDB, Express, React, Node.js) and Java Spring Boot. My focus is on building reliable backend systems and clean, responsive frontend interfaces. 🔹 Backend Development RESTful API design and development (Node.js / Express / Spring Boot) JWT-based authentication and role-based authorization systems Secure password handling and user authentication flows Database integration with MongoDB and relational databases Middleware implementation (logging, error handling, CORS configuration) 🔹 Frontend Development Responsive and interactive UI development using React State management using Context API API integration using Axios Authentication flows (login, registration, protected routes) 🔹 DevOps & Software Practices Basic CI/CD understanding and deployment workflows Git version control and collaborative development Docker fundamentals for containerized applications Agile development methodology and iterative delivery

I'm a full-stack developer working across two focus areas: AI agent development and browser game development. AI & LLM Integrations I build and customize AI agents using Claude Code, ClawdBot, OpenClaw, and related LLM tooling. What I do: - Set up and configure Claude Code for development workflows - Build custom MCP servers and tool integrations - Design and deploy LLM-powered agents and automation pipelines Browser Game Development I also build browser-based games using JavaScript and HTML5, with a focus on smooth physics, responsive controls, and performance optimization. My background includes Minecraft plugin and mod development, so I bring real game design thinking (game loops, state management, player experience) rather than just general web development skills. Recent game projects: - Snooker game with full physics simulation (ball collision, cue control, live scoring) - Real-time browser game style growth and collision mechanics Across both areas, I focus on clean, maintainable code and delivering something that actually works well for the end user, whether that's a smooth AI workflow or a responsive game experience.

Why Choose Me as Your Development Partner? I’m a Senior Full-Stack & Mobile Developer (9+ years) who helps founders and teams turn ideas into production-ready web, mobile, and AI-powered products — fast, clean, and scalable. I combine strong engineering fundamentals with modern vibe-coding workflows to ship faster without cutting corners. ⸻ ✅ Proven Track Record • 🏆 Top 1% Rated Freelancer on Upwork • 🏆 1000+ hours of successful client delivery • 🏆 60+ projects delivered with consistent quality • 🏆 100% Job Success Rate • 🏆 Clean, maintainable, production-ready code ⸻ 🔧 Core Expertise (Full-Stack + Mobile) Frontend & Mobile • React, Next.js, Angular, Vue • React Native, Flutter, Ionic • TypeScript, JavaScript Backend • Node.js, Express • Java (Spring Boot) • Python, Go Databases & APIs • PostgreSQL, MongoDB • REST & GraphQL APIs • Elasticsearch • Vector databases (Pinecone, FAISS, Chroma) Cloud & DevOps • AWS (EC2, S3, Lambda) • Docker, Kubernetes • CI/CD (GitHub Actions, Jenkins) • Terraform (IaC) ⸻ 🤖 AI, RAG & Vibe Coding (Done Right) I build real AI systems, not demos. AI & RAG • OpenAI, Claude, Gemini integrations • End-to-end RAG pipelines (ingestion → embeddings → retrieval → re-ranking) • Secure data sources (PDFs, Docs, Notion, DBs, APIs) • AI chatbots for SaaS, internal tools, and customer support • Token cost & performance optimization Vibe Coding Workflow • Cursor, Windsurf, Claude Code • Replit & Replit Agent • Lovable.dev, Bolt.new • AI-assisted refactoring, testing, and reviews 👉 Human judgment + AI speed = reliable software ⸻ 🌟 How I Add Value I don’t just code — I: • Think like a product owner • Improve existing codebases without breaking things • Reduce tech debt and improve maintainability • Communicate clearly and proactively • Respect timelines, budgets, and existing architecture ⸻ 📩 Let’s Work Together If You Need ✔ Rapid MVPs or startup builds ✔ AI / RAG implementation ✔ Web or mobile app development ✔ Code cleanup, refactoring, or modernization ✔ A reliable long-term development partner 💬 I’m open to negotiation and long-term collaboration.

In the last two years alone, I rebuilt a production stats service processing 100M+ records with >99.9% uptime and <0.2% error rate, and contributed to ad product launches tied to ~$5M in annual revenue. I've also shipped a commercial Shopify app from zero, built multi-channel ad dashboards for ecommerce vendors, and am currently building a healthcare workflow platform as a solo founder — owning the full stack from architecture to AWS deployment. I work across TypeScript, Node.js, Python, React, Next.js, NestJS, PostgreSQL, AWS, Docker, GraphQL, and Redis. I'm comfortable taking a vague problem and turning it into clean, production-ready software — with design docs, realistic timelines, and zero hand-holding required. What I take on: — Backend systems and API design at scale (Node.js, NestJS, Python/FastAPI, PostgreSQL) — Full-stack product development (React, Next.js, TypeScript) — Shopify app development and ecommerce integrations — Data products and multi-source dashboards (Facebook, Google, TikTok APIs) — AWS infrastructure, CI/CD, Docker I've worked async across US, EU, and LATAM teams for years. If you need a senior engineer who ships and communicates like one, let's talk.

I build complete, high-performance web applications, from scalable Java backends to intuitive React frontends. With 10+ years of experience, you can expect clean code, robust architecture, and production-ready systems. 𝐂𝐨𝐫𝐞 𝐒𝐞𝐫𝐯𝐢𝐜𝐞 𝐀𝐫𝐞𝐚𝐬: 𝐁𝐚𝐜𝐤𝐞𝐧𝐝 𝐀𝐫𝐜𝐡𝐢𝐭𝐞𝐜𝐭𝐮𝐫𝐞: High-throughput microservices and APIs using Java Spring Boot, Kafka, and Kubernetes. 𝐏𝐫𝐨𝐯𝐞𝐧: Experience engineering systems that handle 2M+ daily events with sub-200ms latency. 𝐅𝐫𝐨𝐧𝐭𝐞𝐧𝐝 𝐃𝐞𝐯𝐞𝐥𝐨𝐩𝐦𝐞𝐧𝐭: Fast, responsive user interfaces with React.js, Vue.js, and Tailwind CSS. 𝐏𝐫𝐨𝐯𝐞𝐧: Shipped UIs that have cut user onboarding time by 35%. 𝐂𝐥𝐨𝐮𝐝 & 𝐃𝐞𝐯𝐎𝐩𝐬: Architecting production-ready environments with a focus on containerization (Docker, Kubernetes) and complete CI/CD automation (Jenkins, ArgoCD). Great applications are built on a strong partnership and a shared focus on quality. Tell me about your project. Let's see if our goals align.

I'm a Back End Developer with extensive experience in building high-quality sites. I have vast experience building Web services and APIs. I am specialised in backend development using Express in Nodejs or Spring Boot in Java. I love solving problems and I am committed to serve my customers well.

Hello! I'm Swastik Srivastava, a Full Stack Developer and Big Data Consultant with over 5 years of experience delivering scalable, high-performance solutions for startups, enterprises, and global clients. I specialize in building robust systems across the Java ecosystem, Big Data architectures, and data-driven marketing platforms. My work spans across multiple domains including Scala + Spark development, data analytics, digital marketing tech stacks, and end-to-end web applications. 🔧 Core Skills & Expertise: Backend: Java (Spring Boot), Scala, Kafka, REST APIs Big Data: Spark, Hadoop, Hive, Flink, Sqoop, Airflow Cloud: AWS (S3, Lambda, Glue), GCP, Azure (Data Factory, Synapse) Frontend: JavaScript, React, HTML/CSS Databases: MySQL, MongoDB, PostgreSQL DevOps: Docker, GitHub Actions, Jenkins, CI/CD Pipelines Digital Marketing Tech: Google Analytics, Meta Ads Reporting, Marketing Funnels, Email Automation Data Analytics: ETL Pipelines, Dashboards, SQL, Python (Pandas), Power BI ✅ Why Work With Me? Proven track record with top-tier clients (e.g., Morgan Stanley via EY) Ability to lead full-stack projects while coordinating with cross-functional teams Clear communicator who ensures on-time, high-quality delivery You work directly with me — I handle communication and project management, while my internal team supports execution for faster turnaround and flexibility 📈 Services Offered: ✅ Java + Spring Boot Microservices Development ✅ Big Data Pipeline Design with Spark, Scala, Kafka ✅ Digital Marketing Data Analysis & Automation ✅ Web Development & Full-Stack Application Builds ✅ Data Analytics Dashboards & Reporting When I'm not coding, I mentor junior developers and love solving challenging backend and data problems. I'm passionate about helping businesses unlock the full value of their data and digital infrastructure. 📩 Let’s connect! Whether you need a quick fix or a long-term technology partner, I’m always open to a conversation to understand how I can help.

14+ Years of Architecture. 0% Technical Debt. Global Delivery Expert. Stop worrying about technical debt, slow performance, or missed deadlines. I don't just "write code"—I partner with businesses in the US, UK, Australia, and Europe to build enterprise-grade platforms that scale. As a Top Rated Plus Architect with over 11,000 hours on Upwork, I specialize in bridging the gap between complex legacy systems and modern, high-performance web applications. 🚀 What I Solve For You: • Legacy Modernization: Migrating GWT/Java systems to Next.js 15 & React 19 with zero downtime (Lead Architect for Property Vista's 2-year migration). • Scalable SaaS: Engineering multi-tenant platforms with complex RBAC and high-security standards. • Healthcare Compliance: Building audit systems to UK NICE & HIPAA standards (Expert in medical data integrity). • Data Visualization: High-performance D3.js & Highcharts dashboards for real-time anomaly detection. • AI Integration: Automating workflows using Gemini, Claude, and Llama for intelligent business logic. Technical Authority: • Frontend: Next.js 15, React 19, Angular (v14-20), TypeScript, Tailwind CSS. • Backend: Java (Spring Boot, Hibernate), Node.js, REST APIs, Microservices. • Cloud/DevOps: AWS, Azure, Docker, CI/CD Pipelines, GitHub Actions. Why Clients Choose My Architecture: • End-to-End Execution: From database design to React 19 frontends, I handle the full stack so you don't have to manage multiple freelancers. • Audited, Scalable Code: You get fully documented, unit-tested code that is ready for your next 10,000 users. • Honest Roadmaps: No over-promises. I provide realistic milestones and clear technical communication every step of the way. Unsure if your current stack can scale? Message me for a free 15-minute Architecture Consultation. I’ll review your requirements and outline your technical roadmap—completely free of cost.

Top Rated Mobile Developer | Full Stack Mobile & Web Developer | iOS, Android, AI, Kotlin, KMP I help startups turn app ideas into live, scalable mobile products, fast, clean, and built to grow. What I help with: → Mobile App Development → Android App Development → Native App Development → iOS Development → Android → iPad App Development → Kotlin → Mobile App → Java → Android SDK → Hybrid App Development → In-App Purchases → Core Java → Smartphone → Flutter → Android Studio → Android Tablet → Android App → Firebase What I can build for you: → Native Android apps using Kotlin, Jetpack Compose, and Clean Architecture → Cross-platform apps using Kotlin Multiplatform — Android + iOS from one shared codebase → Full-stack mobile and web platforms with scalable backend integration → AI-powered mobile features, automation, smart search, recommendations, and chat experiences → Payment integrations including Stripe, PayPal, and local payment gateways → Real-time features using Firebase, WebSockets, live tracking, and push notifications → Maps, GPS, delivery tracking, location-based services, and Play Store deployment → App optimization for speed, stability, crash reduction, and smaller app size Industries I’ve shipped in: Fintech · E-commerce · Delivery & Tracking · Streaming · Government Services · SaaS · Startup MVPs You’ll get clear communication, realistic timelines, clean code, and a product-focused developer who understands startup speed without sacrificing quality. Send me your app idea, Figma design, or current codebase, and I’ll reply with a clear delivery plan.

Building Reliable Software That Actually Works I'm a software engineer who believes good code isn't just about making things work - it's about making them work well, consistently, and without surprises down the road. Over the past few years, I've specialized in building backend systems and microservices for enterprise applications. My sweet spot is creating APIs and services that handle real-world complexity while staying maintainable and scalable. My technical toolkit: Java • Kotlin • Python • Spring Framework • Docker • Kubernetes • CI/CD • Cloud Infrastructure