Hi 👋, I'm Atiqur, a Senior Software Engineer with over 10 years of hands-on experience building enterprise web applications. I've led development teams and transformed startup ideas into profitable products, including systems that serve millions of users daily. 👨‍💻 Technical Expertise ✅ Full Stack .NET Development – I specialize in complete application development using the Microsoft technology stack, from database design to user interface implementation. ✅ Backend Mastery – Expert in C#, .NET Core/Framework, and ASP.NET MVC. I've optimized systems to handle high traffic loads and reduced processing times from 2.5 seconds to 700ms through performance tuning. ✅ Frontend Skills – Proficient in Razor pages, Angular, TypeScript, JavaScript, and responsive web design. I create intuitive user interfaces that provide excellent user experiences. ✅ Database Optimization – Advanced SQL Server performance tuning, plus experience with MongoDB and Redis for caching and real-time applications. 🚀 What I Deliver • Scalable Solutions – Built applications handling 5+ million active users with 300+ transactions per second capacity • Team Leadership – Successfully led development teams of 4-7 people using Agile methodologies to deliver projects on time • Cost Optimization – Reduced server costs by 10% through efficient resource utilization and smart architecture decisions • Business Impact – Converted startup concepts into revenue-generating products within 12 months 🏢 Industry Experience • E-commerce & Distribution – Developed comprehensive sales and inventory management systems for FMCG and pharmaceutical companies • Telecommunications – Created engaging quiz platforms integrated with major telecom apps, serving millions of users • Enterprise Systems – Built robust distribution management systems that transformed traditional offline processes into efficient online platforms 🔧 Technology Stack • Backend: C#, .NET Core/Framework, ASP.NET MVC, Web API, Entity Framework • Frontend: Angular, TypeScript, JavaScript, HTML5, CSS3, Bootstrap • Databases: SQL Server, MongoDB, Redis • Cloud & DevOps: Azure, AWS, Docker, Git • Tools: n8n automation, SSRS reporting, REST APIs 💡 My Approach I focus on understanding your business needs first, then architect solutions that not only solve immediate problems but scale with your growth. Whether you need to modernize legacy systems, build new applications from scratch, or optimize existing performance, I deliver reliable, maintainable code that drives real business results. Ready to discuss your next project? Let's build something great together!

I am a Full Stack Developer and .NET Developer with 14+ years of experience architecting enterprise-scale systems, building scalable web applications, high-performance REST APIs, microservices architectures, and AI-powered automation solutions using C#, ASP.NET Core, .NET Core 6/7/8, Entity Framework Core, React, TypeScript, Azure, and AWS. Proven track record of reducing infrastructure costs by 25-30% while improving performance by 60-75%. Key Achievements: As a .NET Developer, I delivered 75% faster REST APIs (2000ms to 500ms) using .NET Core optimizations. Processed 100K+ daily API requests and 10M+ daily events with 99.9% uptime. Achieved 99.9–99.99% uptime on Azure/AWS, reducing costs by 25-30%. PROJECT EXPERIENCE Tours and Activities API – Full Stack Developer / Backend Developer / .NET Developer / API Developer Tech: .NET Core 7, ASP.NET Core Web API, C#, Entity Framework Core, SQL Server, Redis, React, TypeScript, Azure Service Bus, Azure Durable Functions, Microservices, Event-Driven Architecture, AWS, Azure, Workflow Orchestration Built enterprise booking API serving 100,000+ daily requests with 99.9% uptime using .NET Core microservices architecture. Implemented event-driven architecture with Azure Service Bus and Azure Durable Functions for workflow orchestration. Achieved 75% API response time improvement (2000ms to 500ms). Developed React frontend with TypeScript. RebookingAtLowerCostEngine – Full Stack Developer / Backend Developer / .NET Developer / API Developer Tech: .NET Core 8, ASP.NET Core Web API, C#, Entity Framework Core, MongoDB, Redis, React, TypeScript, Azure Batch, Azure Durable Functions, Microservices, Event-Driven Architecture, AWS, Azure, Workflow Orchestration Developed AI-powered cost-optimization engine processing 10,000+ hotel reservations daily, achieving 15-30% cost savings through automated rebooking. Built scalable .NET Core microservices architecture with event-driven design using Azure Service Bus and Azure Durable Functions for workflow orchestration. Integrated OpenAI GPT-4 and Python ML APIs for intelligent rebooking recommendations. E-commerce Integration Platform – Full Stack Developer / Backend Developer / .NET Developer / API Developer Tech: .NET Core 8, ASP.NET Core Web API, C#, Entity Framework Core, SQL Server, Redis, React, TypeScript, Azure Durable Functions, Microservices, Event-Driven Architecture, AWS, Azure, Workflow Orchestration Developed enterprise E-commerce integration platform processing 10,000+ products and orders daily with 150+ API endpoints using .NET Core microservices architecture. Implemented event-driven architecture with Azure Service Bus and Azure Durable Functions for workflow orchestration. Integrated 20+ marketplace APIs (Amazon SP-API, Shopify, WooCommerce, Magento, eBay, Mirakl). Logistics Management System – Full Stack Developer / Node Developer / React Developer / API Integration Specialist Tech: Node.js, Express.js, React 18, TypeScript, MySQL, AWS Lambda, AWS Step Functions, Kafka, SQS, SNS, Microservices, Event-Driven Architecture, AWS, Azure, Workflow Orchestration Developed enterprise multi-marketplace synchronization platform supporting 100+ clients with real-time sync across 8+ marketplaces using Node.js microservices architecture. Implemented event-driven architecture with Kafka and AWS SQS/SNS. Used AWS Step Functions for workflow orchestration. Built React 18 frontend with TypeScript. Integrated Amazon SP-API, Shopify, WooCommerce, Magento, eBay, Mirakl APIs. Deployed on AWS. Real Estate Platform – Full Stack Developer / React Developer / Python Developer / TypeScript Developer Tech: Django, Next.js 15.4, React 19, TypeScript, Python, PostgreSQL, Redis, AWS Lambda, AWS Step Functions, Microservices, Event-Driven Architecture, AWS, Azure, Workflow Orchestration Built comprehensive multi-tenant real estate marketplace platform with Django backend microservices and Next.js 15.4 frontend with React 19 and TypeScript. Implemented event-driven architecture with AWS SQS and AWS Step Functions for workflow orchestration. Features include multi-role user management, property listings with location hierarchy, Mapbox GL map integration. Implemented PostgreSQL database with Redis caching on AWS. TECH STACK: C#, .NET Core 6/7/8, ASP.NET Core, ASP.NET Core Web API, Entity Framework Core, LINQ, Microservices Architecture, Clean Architecture, CQRS, Domain-Driven Design, React, TypeScript, JavaScript, SQL Server, PostgreSQL, MongoDB, Redis, Azure Functions, Azure Durable Functions, Azure Service Bus, AWS Lambda, AWS Step Functions, API Gateway, Docker, Kubernetes, GitHub Actions, OAuth2, JWT, SignalR, RabbitMQ, Kafka, REST APIs, gRPC, GraphQL, Amazon SP-API, Shopify API, WooCommerce API INDUSTRIES: Enterprise Software, SaaS Platforms, E-commerce, Financial Services, FinTech, Travel & Hospitality, Logistics, Real Estate

Are you tired of .NET developers who write code but can't own results? I'm a Full-Stack .NET Developer with 7+ years of experience building scalable, high-performance web applications - from SaaS MVPs shipped on schedule to enterprise systems serving thousands of users daily. Here's what that looks like in practice: → Improved legacy application performance by up to 80% through SQL tuning, caching strategies, and architecture refactoring → Delivered SaaS products from zero to production — on time, every time → Built and integrated 20+ REST APIs using ASP.NET Core, EF Core, and clean architecture patterns 🔧 WHAT I BUILD Backend & APIs ✅ ASP.NET Core, .NET 6/7/8/9, C#, Web API ✅ Microservices, Clean Architecture, Domain-Driven Design ✅ RESTful APIs, JWT, OAuth 2.0, Identity Server ✅ Entity Framework Core, Dapper, stored procedures Frontend ✅ Blazor (Server & WebAssembly), Razor Pages ✅ Angular, React - modern, responsive interfaces ✅ TypeScript, JavaScript, HTML5/CSS3 Database & Performance ✅ SQL Server, PostgreSQL, MySQL, MongoDB ✅ Query optimization, index tuning, schema design ✅ Azure SQL, Redis caching Cloud & DevOps ✅ Microsoft Azure (App Services, Functions, Blob, SQL) ✅ Docker, CI/CD pipelines, Azure DevOps ✅ AWS, deployment automation 🎯 WHO I WORK WITH → Startups building their first SaaS product and need a reliable technical partner, not just a coder. → Businesses with legacy .NET systems (Web Forms, old MVC) that need modernization. → Teams that need a full-stack developer who can work independently without hand-holding. 📦 WHAT YOU CAN EXPECT ✔ Clean, maintainable, documented code, not spaghetti ✔ Real communication: daily updates, clear timelines, no surprises ✔ On-time delivery with quality built in, not bolted on ✔ Long-term ownership, I treat your product like my own If you want a developer who ships results, not just code. Let's talk. 📩 Message me with a brief description of your project and I'll respond within a few hours with a clear plan. Technologies & Services Backend: ASP.NET Core · C# · .NET 6/7/8 · Web API · Entity Framework Core · Dapper · SignalR · Microservices · Clean Architecture · DDD · CQRS Frontend: Blazor Server · Blazor WebAssembly · Razor Pages · Angular · React · TypeScript · JavaScript · HTML5 · CSS3 Database: SQL Server · PostgreSQL · MySQL · MongoDB · Azure SQL · Redis · Query Optimization · Stored Procedures Cloud & DevOps: Microsoft Azure · AWS · Docker · CI/CD · Azure DevOps · GitHub Actions · IIS Domains: SaaS Development · Healthcare · E-Commerce · Fintech · Enterprise ERP · EdTech Services: REST API Development · Legacy .NET Migration · Performance Optimization · SaaS MVP Development · Third-Party Integrations · Long-Term Maintenance

I help software companies fix and scale the systems their business runs on. Recent example: I re-architected a payments platform that was failing at ~100 concurrent users into one reliably handling 10,000+ transactions every 15 minutes. Over 15 years I've architected and delivered backend systems for fintech, insurance, and healthcare — industries where reliability, security, and handling sensitive data correctly are non-negotiable. My core work: C#/.NET Core, ASP.NET Web API, Azure (App Services, Service Bus, Functions, Key Vault), SQL Server and PostgreSQL, and clean, maintainable architecture (DDD, microservices, SOLID). Clients bring me in for three kinds of problems: ✔️ A system that breaks, slows down, or fails under load — and needs someone senior to diagnose and fix it properly. ✔️ A new backend or API that has to be built right the first time, with security and scale designed in. ✔️ Ongoing senior architecture and hands-on development for a product that has outgrown its current setup. I also build AI-powered features into applications — agentic workflows and LLM integrations using the OpenAI and Claude APIs, and RAG-based functionality — engineered on a solid backend so they're reliable, secure, and maintainable rather than fragile demos. I take on a small number of engagements at a time so each client gets senior attention. With Expert-Vetted status, 100% Job Success, and 9,500+ hours on Upwork, you can expect senior-level work and reliable delivery. If you have a system that needs to work properly, let's talk.

Claude Certified Architect (Anthropic) — designing and shipping production Claude applications. I use Claude Code, Cursor, and GitHub Copilot to deliver production-quality results significantly faster — without cutting corners on architecture or code quality. I'm a Senior .NET & Vue Developer with extensive Upwork experience, specializing in scalable SaaS platforms, enterprise systems, and long-term business applications. I help companies turn complex requirements into stable, high-performance software that is easy to maintain and built to grow. All architectural and technical decisions are fully mine — AI tools simply make my workflow faster and more precise. Beyond development, I also do prompt engineering — designing structured, reliable prompts and AI workflows that integrate cleanly into real products. What I Do Best: Full-Stack Development (.NET Core + Vue.js / Angular / React) Scalable Architecture (DDD, CQRS, Clean Architecture) API Development & Integration (REST, gRPC, OAuth) Cloud & DevOps (Azure Pipelines, AWS, Docker, SonarQube) High-Performance Systems (Caching, SQL Optimization) Prompt Engineering & AI Workflow Integration Why Clients Choose Me: Deep expertise across backend, frontend, and DevOps Proven with high-traffic and enterprise systems Clear communication, fast delivery, and clean code

As a highly skilled and experienced .NET developer with over 7 years of experience, I have a deep understanding of the .NET framework and related technologies, including C#, ASP.NET, ASP.NET MVC5, ASPNET Core, and Identity. Additionally, I have expertise in modern front-end technologies, particularly ReactJS. This allows me to deliver end-to-end solutions for web and mobile applications. I have a proven track record of delivering high-quality software on time and within budget, using Agile development methodologies and database management (SQL Server, MySQL, MongoDB). I am a problem solver, a creative thinker, and a dedicated professional who is always up-to-date with the latest technologies and programming languages. I am passionate about creating innovative software solutions and am always willing to go the extra mile to ensure the success of a project. I have a degree in Computer Science and several certifications in .NET development and have a portfolio of successful projects and positive client feedback.

Web Client Development Windows Client Development Windows Services Development Websites Design & Development Web API Development Web API Integration Azure Cloud Solutions Development ML/AI Solutions Development ChatBot Development PowerBI Custom Visuals Development Tableau Extensions Development 20 years of experience in the industry. Technologies Used =============== Microsoft Visual Studio 2019 Microsoft Visual Studio 2022 Microsoft .Net Frameworks 4.7 Microsoft .Net Core 3.1 Microsoft .Net Core 5 Microsoft .Net Core 6 Microsoft SQL Server 2014 Microsoft SQL Server 2018 MySQL Microsoft Windows APIs C# .Net MVC Razor HTML 5 JQuery JQuery KineticJS JavaScript Node.JS AngularJS TypeScript React.JS JQuery ASP.Net WCF REST SOAP XML Open XML SDK XSLT WMI Team Foundation Server Microsoft Visual Sourcesafe Tortoise SVN Microsoft Visio Rational Rose Enterprise UML Microsoft SQL CLR T-SQL IIS Microsoft Azure Microsoft Dynamics 365 (CRM) Microsoft PowerBI Tableau Microsoft PowerApps MassTransit / RabbitMQ Web Services Web API Google Scripts ML / AI Natural Language Processing ShopifySharp Twitter API V2 QuickBook API Sage 50 API Stripe APIs & Elements Paddle

I have helped startups and enterprises build new .NET applications, define solution architecture, modernize legacy systems, resolve complex production issues, optimize application and database performance, simplify backend complexities, integrate third-party systems, and become a dependable long-term member of their development teams over 20 years of my experience. If you're looking for someone who can step into an existing .NET application, quickly understand the codebase, identify the real problem, and start delivering without constant guidance, I'd be happy to help. Over the years, I've worked on challenges that go far beyond code writing, code—performance tuning, troubleshooting production issues, designing scalable backend architectures, optimizing SQL queries, refactoring legacy applications, integrating external APIs, resolving concurrency and data consistency issues, improving application stability, and implementing new features without disrupting existing business workflows. I am hands-on developer and enjoy solving the technical challenges. My Core Areas of Expertise:- ------------------------------------ ✔ ASP.NET Core, .NET Framework, .NET 6/7/8, C# ✔ REST APIs, Web APIs, Microservices & Third-party Integrations ✔ Full Stack Development using ASP.NET Core, Angular, Blazor & MVC ✔ Legacy .NET Modernization (ASP.NET, Windows Forms, WPF) ✔ Enterprise & SaaS Application Development ✔ SQL Server, MySQL, Entity Framework Core & NHibernate ✔ Performance Optimization, Database Tuning & Application Troubleshooting ✔ Cloud Deployment with Azure, AWS, Git, Jenkins & CI/CD Pipelines ✔ ABP Framework & ASP.NET Zero I've successfully delivered projects for clients across the USA, Australia, Canada, France, Russia, and India. My recent Upwork engagement lasted over two years with more than $52,000 billed, and I've maintained 5-star ratings across every completed Upwork project. If you're looking for a senior .NET consultant who can quickly become productive, take ownership of your application, and deliver reliable results, I'd be happy to discuss your project.

Looking for smarter business applications, modern web experiences, and scalable back-end systems that drive real results? That’s exactly what we build. We are also ISO 42001 and ISO 27001 certified, ensuring strong AI governance and enterprise-grade information security. We are a team of seasoned .NET and Microsoft technology specialists with 10+ years of experience delivering secure, high-performance, and cloud-ready applications. From modernizing legacy platforms to building enterprise-grade web, API, and cloud-native solutions, we provide end-to-end .NET development that supports digital transformation and business growth. We also leverage AI tools in our development workflow to accelerate delivery, enhance code quality, and enable intelligent features within applications. .NET & Microsoft Ecosystem ASP.NET Core / MVC / Web API / Blazor (Server & WebAssembly) C# / VB.NET with SOLID principles and clean architecture Entity Framework Core, LINQ, Dapper .NET MAUI / Xamarin for cross-platform mobile & desktop apps Identity & Security: ASP.NET Identity, OAuth2, JWT, Azure AD Modernization: .NET Framework → .NET 6/7/8 migrations Backend Development & Architecture RESTful & API-driven architectures Microservices with DDD, CQRS, Event‑Driven patterns SignalR for real-time applications Background Processing: Hangfire, Quartz.NET, Worker Services, Azure Functions Messaging & Queues: Azure Service Bus, RabbitMQ, Kafka Performance Optimization & Caching: Redis, MemoryCache Front-End & UI Development Blazor, React, Angular ASP.NET Core Razor Pages & MVC Legacy modernization: WebForms & Silverlight → Blazor / React Responsive UI: HTML5, CSS3, Bootstrap, Tailwind CSS State Management: Blazor State, Redux, Context API Cloud, DevOps & Deployment Microsoft Azure: App Services, Functions, Logic Apps, API Management Databases: SQL Server, Azure SQL, PostgreSQL, MySQL, Cosmos DB, MongoDB Containerization: Docker, Kubernetes, Azure Container Apps CI/CD: Azure DevOps, GitHub Actions, Jenkins Monitoring & Telemetry: Application Insights Infrastructure as Code: ARM, Bicep, Terraform Data, Integration & Analytics Data Access & Reporting: ADO.NET, EF Core, SSRS, Power BI Integrations: REST, gRPC, SOAP, OData, Graph API ETL & Migration: SSIS, Azure Data Factory, Snowflake integration AI‑Driven Development: We use GitHub Copilot and Claude daily to accelerate coding, improve architecture decisions, and produce clean, well‑documented code. We also build and integrate Azure OpenAI / OpenAI‑powered features for intelligent automation, chat assistants, and enterprise‑ready AI solutions. If you’re looking for a reliable .NET full‑stack team that combines modern UI, robust back-end systems, cloud-native delivery, and automation, let’s connect #DotNet #CSharp #ASPNetCore #Blazor #WebAPI #MVC #EntityFramework #Dapper #Azure #AzureDevOps #GitHubActions #Docker #Kubernetes #Microservices #React #Angular #MAUI #Xamarin #SQLServer #CosmosDB #RESTAPI #gRPC #SignalR #PowerShell #OpenAI #CloudMigration #Modernization #FullStackDevelopment #BackendDevelopment #FrontEndDevelopment #EnterpriseApps #CleanArchitecture #SOLID #AgileDelivery #AIIntegration #FullStackDevelopment #Azure #GitHubCopilot #ClaudeAI #AzureOpenAI #LLM #Microservices #CloudNative #Automation #ISO42001 #ISO 27001

With more than ten years of experience as a Senior .NET Engineer, I have worked on designing and building strong software solutions for different companies. My main focus is always on building high-quality and reliable systems that can handle heavy workloads and help businesses solve complicated problems. I am committed to using modern software development methods and DevOps practices to make sure every project runs smoothly, is easy to maintain, and truly helps the business. I always try to create software that not only works well today, but can also be improved or changed easily in the future. A key part of my approach is to use Domain-Driven Design, which helps me understand the business and make sure the software matches its needs. I also use Clean Architecture to organize my code so it stays simple, easy to test, and flexible over time. This helps reduce future costs and avoids messy, hard-to-maintain code. I have a full range of technical skills, with a strong focus on the .NET framework, especially C#, ASP.NET Core, and Entity Framework Core. On the user interface side, I have built many web applications using both React and Angular, so I am comfortable working on both the backend and frontend of software projects. My ability to handle all parts of a project means I can lead teams and solve problems at every step of development. I also have hands-on experience deploying cloud-based software using both Azure and AWS. I am skilled at setting up and handling continuous integration and delivery pipelines, mainly with GitHub Actions. Automating the build, test, and deployment process saves a lot of time and helps my team deliver updates faster, more reliably, and with more confidence. Quality is very important to me, and I always make sure that we have strong tests at every level, from small parts of the code to the whole system, so the final product is stable and fast even when many users are online. I have used these skills to make big improvements to large platforms handling millions of transactions, where performance and stability are crucial. In my career, I have worked for clients across different fields, such as financial technology, education, and travel. Some important achievements include designing a portal that serves many clients for the EdTech industry, building advanced API connections for a global travel company, and leading updates for older ERP systems to make them modern and efficient. In every job, I always aim to turn business ideas into technology solutions that support growth and innovation. My technical knowledge is built on a strong foundation in information systems and technology management, with a degree in Management Information Systems. This education helped me understand both how to build good software and how to connect technology plans to business goals. I learned a mix of technical and business skills, including software development, databases, networks, business analysis, and project management. These skills let me build solid products while making sure they solve real business challenges. I am now looking for new opportunities where I can use my skills to build creative and scalable software solutions. I am confident that my strong background, leadership experience, and dedication to excellent quality would make me a good addition to your team.