Abhishek Yadav Full-Stack Developer | Next.js | React.js | Node.js | FastAPI | AI Integrations $20.00/hr ⚡ A results-driven backend and full-stack engineer with 3+ years of experience building scalable SaaS platforms, AI-powered applications, and high-performance microservices using FastAPI, Node.js, Next.js, PostgreSQL, Kafka, and Docker. 🏢 Experience contributing to enterprise-grade systems at Y Combinator–backed startups and global engineering teams, delivering secure, reliable, production-ready solutions used by thousands. Core Expertise: 🛠 Backend Engineering & APIs • FastAPI, Node.js, Python • REST APIs, OpenAPI, Webhooks, 3rd-party Integrations • Sentry Integrations, Slack, Linear, Google OAuth 🤖 AI & Automation • AI-powered debugging and analytics systems • OpenAI API, LlamaIndex, RAG pipelines • Real-time event processing and insights 💻 Full-Stack / Frontend • React, Next.js, TypeScript, Tailwind • Responsive UI & reusable component systems • Authentication, sessions, dashboards, admin systems 🗄 Databases & Streaming • PostgreSQL, MongoDB, Redis • Kafka-based event ingestion pipelines • Query optimization, schema design, migrations Development Philosophy: 🎯 I collaborate closely with clients to understand their needs, architect robust solutions, and deliver clean, maintainable, and scalable code. 🎯 I prioritize performance, reliability, and developer experience, ensuring every system is easy to debug, monitor, and extend. 🎯 My workflow is transparent, communication-focused, and optimized for rapid iteration without compromising quality. What You Can Expect: ✔ High-quality engineering with strong API design fundamentals ✔ Production-grade code and clear documentation ✔ Ownership, accountability, and on-time delivery ✔ A partner who solves problems, not just writes code

Full Stack Engineer — Backend, IoT, Blockchain & Analytics Systems Most clients reach me when something isn't working — a developer disappeared, a smart contract has a bug nobody can trace, or an IoT system that looked fine in testing falls apart on real devices. That's usually when I get the message. I'm Ahmed. Over the past 06 years I've built production-grade systems across IoT infrastructure, blockchain, fintech, and analytics — not because it's trendy, but because hard problems are more interesting to work on. I started Nexiotix to do this properly — as a specialist team, not a generalist agency that stretches itself thin. — IoT Platform (Ezlo/MiOS): 4+ years contributing to a large-scale smart home ecosystem — 300+ Node.js and Golang microservices deployed on Docker and Kubernetes, with Kafka, RabbitMQ, and MQTTS for real-time device communication. Monitoring via Prometheus, Grafana, and OpenTelemetry. Runs on thousands of real devices globally. — Crypto & Visa Card Platform: Built a crypto-to-fiat spending system that converts digital assets into USD/AED for online and in-store use across the UAE. Covered KYC verification (3–5 min), dedicated deposit addresses, Apple/Google Pay, and multi-tier Visa card models with dynamic spending limits. — Blockchain & Web3: Smart contracts, DeFi mechanics, staking and withdrawal systems using Ethers.js and Thirdweb SDK. Deployed to Polygon mainnet. Security is non-negotiable here. — Dealership Analytics (MyDealerKPI): High-performance multi-user, multi-department reporting portal serving hundreds of automotive dealers across the US. Real-time dashboards across sales, service, inventory, and trade-in using ClickHouse, Kafka, MySQL, MongoDB, and Redis. Core stack: Node.js (NestJS, Express) · Golang (Fiber, GORM) · Angular · Kafka · RabbitMQ · MQTT · Docker · Kubernetes · AWS · PostgreSQL · MySQL · MongoDB · ClickHouse · Redis · GraphQL · gRPC · Ethers.js · Thirdweb SDK · Prometheus · Grafana · OpenTelemetry · CI/CD (Jenkins, GitHub Actions) I've never missed a deadline. When something changes, I communicate — I don't go quiet. Handover includes documentation you can actually use. If your project is straightforward, there are cheaper options and I'll tell you honestly. But if it's technically complex, time-sensitive, or has already failed once — that's the situation I work best in.

I'm a Senior Full-Stack Engineer, Solution Architect, and Technical Lead with 10+ years of experience building scalable products, high-performance backend systems, AI-powered applications, and cloud-native platforms. I've led engineering teams, architected enterprise applications from scratch, and delivered production systems used by financial institutions, NBFCs, SaaS companies, and travel businesses. I enjoy solving complex engineering problems—whether it's designing distributed systems, optimizing databases, building AI agents, or developing modern web and mobile applications. My expertise spans the entire product lifecycle, from architecture and backend development to frontend, cloud infrastructure, DevOps, and AI integration. What I work with • Backend: Node.js, NestJS, Express, PHP (Laravel), Java, REST APIs, GraphQL • Frontend: React, Angular, TypeScript, JavaScript • Mobile: React Native, Android (Java/Kotlin) • Databases: PostgreSQL, ClickHouse, MySQL, Redis, MongoDB • Cloud & DevOps: AWS, GCP, Docker, Kubernetes, Nginx, CI/CD, Linux • AI & Automation: OpenAI, LangChain, LangGraph, AI Agents, RAG, Machine Learning integrations, NLP • Data Engineering: ETL pipelines, analytics platforms, reporting systems, real-time data processing Industry Experience • FinTech & Lending Platforms • Banking & NBFC Solutions • Travel & Flight Booking Systems • SaaS Products • Business Intelligence & Analytics • Enterprise Workflow Automation One of the products I architected and continue to lead is ByteLoom, an enterprise analytics and business intelligence platform used by lending organizations to manage reporting, dashboards, data pipelines, and operational insights at scale. I believe great software starts with good architecture. Rather than simply writing code, I help businesses choose the right technologies, design scalable systems, and build products that are maintainable for years. Whether you need to build a product from scratch, modernize an existing application, optimize performance, integrate AI, or scale your infrastructure, I can help. Core Expertise ✔ Full-Stack Development ✔ System Architecture ✔ API Development ✔ AI Agents & LLM Integration ✔ Machine Learning Integration ✔ Cloud Architecture (AWS & GCP) ✔ Database Design & Optimization ✔ Performance Tuning ✔ DevOps & CI/CD ✔ Enterprise SaaS Development ✔ Mobile Application Development ✔ Business Intelligence & Data Engineering I'm passionate about building reliable, scalable software that solves real business problems—not just delivering code.

I architect and ship cloud-native systems end-to-end - and I'm one of the few AWS architects who also builds production AI: LLM agents, RAG pipelines, and AI workflow automation that run live, not in demos. Recent work: Built an AI sales agent platform on AWS and Claude API - conversational lead qualification, automated booking, and real-time lead scoring with a live admin dashboard. Watch the demo in my portfolio. Implemented BYOC (Bring Your Own Cloud) deployment for Vertex3d, an enterprise 3D/CAD streaming platform serving 350,000+ users in aerospace and manufacturing - CDK-synthesized CloudFormation deployed inside customers' own AWS accounts for IP protection and compliance. Designed the real-time data pipeline for OvationUp, an AI guest-feedback platform for national restaurant chains - MongoDB to ClickHouse via Debezium on AWS MSK, powering location-level analytics. Led large-scale cloud migrations at Gameloft (Montreal): on-premise to AWS and Alibaba Cloud for game backends serving 100,000+ concurrent users, cutting operational costs ~30% in year one. What I do: CLOUD ARCHITECTURE & MIGRATION - AWS-native design, multi-account strategy, CDK/Terraform infrastructure as code, Kubernetes, cost optimization, CI/CD that works at scale. AWS Certified DevOps Engineer Professional. AI INTEGRATION - Claude and OpenAI APIs, RAG architectures, AI agents, and workflow automation integrated into real products. I've shipped content-generation pipelines and AI-assisted workflows running in production. FULL-STACK DELIVERY - NestJS, React, Next.js, PostgreSQL, TypeScript. I build and ship production APIs and frontends, not just advise on them. I work with founders and CTOs as a hands-on technical lead, from first architecture decision to deployment. When a project needs a team, I bring one. M.Eng Software Engineering, Concordia University (Montreal). Based in Chennai, working US/Canada hours overlap.

I build and customise Shopify and WordPress stores for businesses that need more than a default theme or plugin can offer. I also work with Python and Django on the backend, useful when a store or site needs custom logic beyond what standard apps or plugins can handle, automated workflows, CRM integrations, custom order processing. 𝗪𝗶𝘁𝗵 𝗦𝗵𝗼𝗽𝗶𝗳𝘆 𝗜 𝗰𝗮𝗻 𝗮𝘀𝘀𝗶𝘀𝘁 𝘆𝗼𝘂 𝘄𝗶𝘁𝗵 ✔ Custom Shopify theme development and design changes ✔ Custom Shopify app development using Shopify APIs ✔ Store setup, migration and configuration ✔ Payment gateway integration, Stripe, PayPal, Razorpay 𝗪𝗶𝘁𝗵 𝗪𝗼𝗿𝗱𝗣𝗿𝗲𝘀𝘀 𝗜 𝗰𝗮𝗻 𝗮𝘀𝘀𝗶𝘀𝘁 𝘆𝗼𝘂 𝘄𝗶𝘁𝗵 ✔ Custom plugin development for specific business logic ✔ WooCommerce setup, customization and store management ✔ Headless WordPress, using WordPress as a backend with React or Next.js frontend ✔ Performance optimization and security hardening for existing WordPress sites 𝙊𝙫𝙚𝙧𝙖𝙡𝙡 𝙀𝙘𝙤𝙢𝙢𝙚𝙧𝙘𝙚 & 𝙒𝙚𝙗 𝙎𝙪𝙥𝙥𝙤𝙧𝙩 ✔ Third party integrations and REST APIs ✔ Product, inventory and order automation ✔ Site speed optimization and mobile responsiveness Here are my Tech stacks where I am strong : 𝙎𝙝𝙤𝙥𝙞𝙛𝙮, 𝙎𝙝𝙤𝙥𝙞𝙛𝙮 𝘼𝙋𝙄𝙨, 𝙇𝙞𝙦𝙪𝙞𝙙, 𝙒𝙤𝙧𝙙𝙋𝙧𝙚𝙨𝙨, 𝙒𝙤𝙤𝘾𝙤𝙢𝙢𝙚𝙧𝙘𝙚, 𝙎𝙦𝙪𝙖𝙧𝙚𝙥𝙖𝙘𝙚, 𝙁𝙞𝙭, 𝙒𝙚𝙗𝙛𝙡𝙤𝙬 & 𝙋𝙃𝙋 I make sure to deploy clean code with fast load times and sites that stay stable as more features get added. So if you need a Shopify store or WordPress site built, fixed or made faster then let's us connect and talk about it 🙂

🚀 8+ Years of Turning Data Into Decisions, Automation & AI That Actually Works. I don't build demos or scripts that break in production. I build AI systems, ML models, and data pipelines that businesses run on every single day — reliably, at scale, with real business impact. Startups, agencies, research labs, and enterprise clients hire me to solve one core problem — how do we turn our data into something intelligent, automated, and profitable? Answer: Python + AI/ML + real engineering discipline. Fine-tuned LLMs, RAG chatbots trained on your knowledge base, scrapers pulling millions of pages daily, computer vision in production, multi-agent AI crews — I've built it, shipped it, and maintained it. ━━━━━━━━━━━━━━━━━━━ 🧠 AI, LLMs, RAG & Agentic Systems : • LLM Integration — OpenAI GPT-4o, Claude, Gemini, LLaMA, Mistral, DeepSeek • RAG Pipelines — ingestion, chunking, reranking, hybrid search, HyDE • Agentic AI — LangChain, LangGraph, CrewAI, OpenAI Agents SDK, MCP • Multi-Agent Workflows — supervisor-worker, crews, human-in-the-loop • Fine-Tuning — LoRA, QLoRA, PEFT, DPO on custom domain data • Vector Search — Pinecone, Weaviate, Chroma, pgvector, FAISS, Qdrant • Prompt Engineering, Guardrails, Structured Outputs ━━━━━━━━━━━━━━━━━━━ 🤖 Machine Learning & Deep Learning : • Supervised, Unsupervised & Reinforcement Learning • Classification, Regression, Clustering, Anomaly Detection • Time-Series Forecasting (Prophet, LSTM, XGBoost) • Recommendation Systems & Ranking Models • Computer Vision — YOLO, Detectron2, OCR, Segmentation • Deep Learning — CNNs, LSTMs, Transformers, GANs, Diffusion • Transfer Learning, Quantization, Hyperparameter Tuning Frameworks: TensorFlow, PyTorch, Keras, JAX, Scikit-Learn, XGBoost, LightGBM, Hugging Face ━━━━━━━━━━━━━━━━━━━ 📝 Natural Language Processing (NLP) : • Text Classification, Sentiment & Emotion Analysis • NER, Relation Extraction, Topic Modeling • Summarization, Translation, Q&A Systems • Document Intelligence — PDF parsing, table extraction, OCR • Speech — Whisper, ElevenLabs, Deepgram Libraries: spaCy, NLTK, Hugging Face Transformers, LangChain, LlamaIndex, Haystack ━━━━━━━━━━━━━━━━━━━ 🕸️ Web Scraping & Data Extraction : • Enterprise scrapers — millions of pages, zero downtime • Anti-bot bypass — Cloudflare, DataDome, PerimeterX • CAPTCHA solving, fingerprint spoofing, TLS fingerprinting • Proxy rotation — residential, datacenter, mobile IPs • JavaScript sites, SPAs, infinite scroll, API reverse engineering • Scheduled ETL pipelines with retry logic & monitoring Tools: Scrapy, Selenium, Playwright, Puppeteer, BeautifulSoup, aiohttp ━━━━━━━━━━━━━━━━━━━ ⚙️ Backend & API Development : • FastAPI — high-performance async APIs with auto-docs • Django & DRF — full-featured web applications • Flask — lightweight microservices • REST, GraphQL & gRPC APIs • WebSockets, async programming, Celery, Redis Queue • Auth — JWT, OAuth 2.0, SSO, API keys ━━━━━━━━━━━━━━━━━━━ 📊 Data Engineering & Visualization : • Data Cleaning, Feature Engineering, Statistical Testing • ETL Pipelines — Airflow, Prefect, Dagster • Big Data — Pandas, Dask, PySpark, Polars • Dashboards — Streamlit, Dash, Gradio, Plotly ━━━━━━━━━━━━━━━━━━━ 🗄️ Databases : • SQL — PostgreSQL, MySQL, ClickHouse, TimescaleDB • NoSQL — MongoDB, Firebase, Redis, DynamoDB • Vector DBs — Pinecone, Weaviate, Chroma, pgvector, Qdrant • Warehouses — BigQuery, Snowflake, Redshift, Databricks ━━━━━━━━━━━━━━━━━━━ ☁️ Cloud, DevOps & MLOps : • AWS (SageMaker, Bedrock, Lambda), GCP (Vertex AI), Azure ML • Docker, Kubernetes, Terraform, CI/CD • MLflow, W&B, DVC, BentoML for model deployment • Monitoring — Prometheus, Grafana, Sentry ━━━━━━━━━━━━━━━━━━━ 💡 Real Problems I Solve : • "Build a RAG chatbot trained on our 10,000 internal docs" • "Scrape 500K product listings daily without getting blocked" • "Fine-tune an LLM on our support tickets for auto-responses" • "Predict customer churn 30 days before it happens" • "Extract structured data from thousands of PDFs and invoices" • "Build a multi-agent AI crew for our research workflow" • "Detect defects on our assembly line with computer vision" ━━━━━━━━━━━━━━━━━━━ 🏭 Industries: Finance, Healthcare, E-commerce, Real Estate, Marketing, Logistics, Legal, EdTech, SaaS, Manufacturing. ━━━━━━━━━━━━━━━━━━━ ⭐ Why Clients Trust Me : • 8+ years of production Python, ML & AI engineering • End-to-end delivery — data to model to deployment to monitoring • Deep expertise across LLMs, RAG, NLP, scraping, DL & MLOps • Clean, tested, documented code — not throwaway scripts • Business-first thinking — right questions before writing code • Clear communication, honest timelines, long-term reliability ━━━━━━━━━━━━━━━━━━━ 📩 Send me a message with your project — let's turn your data into your competitive advantage.

Software development expert and problem solver. API Integration expert. 16+ years of professional experience. More than 26.000 hours worked on UpWork with 100% job success. Long experience in Enterprise TeleHealth platforms and Cybersecurity solutions. I write high-quality, well tested and clean code. I am a very responsible person and you can rely on me. I have scientific background. Very good and fast in understanding of the any type of existing code. Experience in telemedicine platforms and cybersecurity solutions. I'm hard worker and really love my job. :) My skills relevant for this moment: ✓ Programming Languages: C#, JavaScript, TypeScript. ✓ Server side: ASP.NET Core, Web API, RESTful API, Entity Framework, ADO.NET, LINQ, Redis, nUnit, nInject. ✓ Client side: Angular, AngularJS, Bootstrap, HTML, CSS, jQuery, SignalR ✓ DBMS: MS SQL Server, Clickhouse, MySQL, SQLite; ✓ AIs: Claude, Cursor ✓ Brokers: RabbitMQ, MSMQ, Kafka, Azure Service Bus ✓ Payments integration: Authorize.Net, Chargify, Stripe, Hint, Paymentwall; ✓ Email integration: MailGun, Gmail, SendGrid, custom SMTP; ✓ Reports integration: PowerBI, LogiReports, Crystal Reports; ✓ Medical partners inegration: Hint, Redox, EazyScripts, AthenaHealth, PokitDok, RxNT; ✓ SMS integration: Twilio, Plivo; ✓ Url shortner integration: Bitly, Blink; ✓ Authentication: JSON Web Tokens (JWT), Azure AD OpenID Connect (OIDC), OAuth2, SSO, MSAL, ADAL ✓ DevTools: Visual Studio .NET 2026 / 2022/ 2019, Jetbrains Rider, VS Code, ReSharper, Postman, SQL Server Management Studio, SQL Server Query Analyzer, DevOps ✓ Other: Git, Agile, Scrum, Assembla, Jira, C# development for MacOs and etc.

I help startups and product companies build reliable backend systems, scale products, and solve performance bottlenecks. Over the past 5+ years I've built backend systems for SaaS, AdTech, IoT, EdTech, e-commerce, CRM/ERP, and business automation solutions. SELECTED RESULTS ▪ 50K–130K RPS — Go microservices for a real-time AdTech platform ▪ 100+ connected IoT devices — built an IoT self-service platform with payments and device management ▪ 40% fewer production defects — improved code reviews, testing standards, and engineering practices ▪ 3× faster releases — streamlined development workflows and team processes ▪ 80% faster synchronization — optimized processing for more than 100,000 SKUs ▪ 4 hours saved every day — automated repetitive internal business processes HOW I CAN HELP ▪ Build a backend product from scratch or take over an existing one ▪ Scale applications that are outgrowing their current architecture ▪ Design APIs, integrations, and service-oriented architectures ▪ Find and remove backend and database performance bottlenecks ▪ Modernize legacy PHP applications without disrupting the product ▪ Integrate payment providers and automate business workflows ▪ Review architecture, code quality, and engineering processes BEYOND THE CODE I've led engineering teams, mentored developers, interviewed candidates, and worked closely with product owners and stakeholders. I’m comfortable taking ownership of a technical problem, understanding the business context, and finding a practical solution—not just completing isolated development tasks. CORE STACK PHP / Laravel / Symfony / Go PostgreSQL / MySQL / Redis / Aerospike / QuestDB Docker / AWS / REST APIs / Microservices / CI/CD Have a backend problem that needs more than just another developer? Send me a message and tell me what you're building, what isn't working, or where the product needs to go next.

I build production RAG systems, LLM-powered chatbots, and backend APIs that hold up under real use. At Turing, I worked on Meta's LLaMA pipeline, guiding the model through GitHub issue debugging, reasoning-chain generation, and patch validation. Recent client work: a RAG-based Telegram chatbot for medical analysis (LangChain + OpenAI), a fine-tuned Text-to-SQL model, and event-driven data pipelines with ClickHouse. What I do best: - RAG systems and LLM-powered chatbots - LLM evaluation and prompt engineering - FastAPI / Flask backend development - Data pipelines and API integrations I write clean code and care about what works in production, not just in a demo. Let's talk if you need someone who understands both the AI and the engineering underneath it.

Senior QA engineer/SDET - Top Rated ⭐️, 100% Job Success across ~6000 hours 💪 I don't churn clients: I embed like an in-house engineer and stay, not a vendor who vanishes after a sprint. My edge is the testing most QA can't do: AI/LLM product testing - evaluating LLM output quality with DeepEval and LangFuse, catching prompt-injection and security holes, load-testing inference endpoints -on top of solid end-to-end automation (Playwright/TypeScript, WebdriverIO) and deep API/contract testing. Across my career that's looked like: 🟢 Rebuilt a global marketplace's test suite from ~80 fragile tests to 2,700 automated E2E tests (~90% coverage), cutting full regression to ~2 hours and enabling two releases a week 🟢 On a healthcare neuro-diagnostics platform (web + iOS), introduced an OWASP security pass that caught exposed client-side API routes before they reached production, and drove pre-release bugs down ~4–5× (226+ defects caught, 400+ test cases authored). 🟢 On an AI support-assistant SaaS, I own LLM-output evaluation inside CI, so quality and tone regressions are caught before each release - not by users. I work best as an embedded QA owner for not large engineering teams on short release cycles: setting test strategy, building the automation, and translating quality and risk into business terms. I spent seven years in B2B sales before QA, so I talk to founders and CTOs, not just engineers. Domains I know first-hand: ⚖️ marketplaces, 💊healthcare, 💸 fintech/payments, 🤖 AI/LLM SaaS, 🛍 e-commerce. 🧰 Stack: Playwright (TS), WebdriverIO (JS), Appium | DeepEval, LangFuse, prompt-injection & agent eval | Postman / Postman Flows, Swagger, contract testing | k6 | BrowserStack, iOS | GitHub Actions, GitLab CI, Docker | Allure, Zephyr, Qase, Jira ➡️not finalized list though, I always learn something new. If you need someone who'll own quality end-to-end and still be here in a year - let's talk 📞