Need to automate workflows, integrate AI, or build a backend that scales reliably? I’m Hao, a Senior Full-Stack Engineer with 5+ years of experience building production-ready applications, automation systems, data pipelines, and cloud-native backend services. I help businesses turn complex technical challenges into practical, scalable solutions, including: ✅ Workflow Automation & Data Pipelines Event-driven pipelines, business process automation, API integrations, and marketing platform integrations such as Google Ads and Facebook Ads. ✅ AI & Generative AI Solutions AI-powered product features, model fine-tuning with LoRA, Hugging Face deployments, and generative AI integrations built for real-world use. ✅ Scalable Backend Development High-performance microservices and APIs using Python, Java, Go, and Spring Boot, deployed across AWS and Google Cloud. What you can expect when working with me: - Clean, maintainable, and well-tested code - Reliable architecture designed for scale - Clear communication and practical documentation - Solutions aligned with your business goals, not just technical requirements Whether you are launching an AI feature, improving internal operations, or scaling a cloud platform, I can help you build it efficiently and reliably. Let’s discuss your project and turn your idea into a production-ready solution.

I’m an experienced Integration Developer with over 8 years in the IT industry, specializing in API development, integration solutions, and full-stack web & mobile applications. I’ve successfully delivered scalable and secure solutions using MuleSoft, Java, and Spring Boot, and have hands-on expertise across both backend and frontend technologies. 💼 Core Skills: Integration & Middleware: MuleSoft Anypoint Platform (3.x & 4.x), API Design, RAML, CloudHub, RTF, CI/CD (Jenkins, Azure DevOps) Backend Development: Java, J2EE, Spring Boot, Spring MVC, Hibernate, Microservices Frontend Development: Angular, HTML, CSS, JavaScript Mobile Development: Android (Java/Kotlin) Other Technologies: Node.js, Python, Jasper Reports, Apache Tomcat Databases: MySQL, SQL Server, PostgreSQL, SQL Deployment & Tools: SFTP, OAuth 2.0, REST, Git, Postman, SOAP 🔧 What I Offer: End-to-end integration solutions using MuleSoft and microservices Full-stack development with Java, Angular, Node.js, and Python Android app development with robust backend integration Database design, optimization, and complex query development Clean, maintainable code and proactive communication I’m passionate about building efficient, reliable systems and am open to both short-term and long-term Upwork engagements. If you're looking for a versatile developer who can handle both integration and full-stack tasks, let’s connect!

I’m a Senior Software Engineer with strong experience designing and building scalable, cloud-native systems on AWS for startups and growing products. My strength is turning business requirements into reliable technical solutions — from early MVPs to production systems that scale without costly rewrites. What I focus on: Backend and full-stack development AWS cloud architecture (serverless & cloud-native) Scalable system design and clean APIs Performance, reliability, and cost efficiency Working closely with founders and product teams I’ve worked on financial and SaaS platforms, where reliability, security, and clear architecture are critical. I care about writing clean, maintainable code and making technical decisions that support long-term growth, not shortcuts. Clients value me for clear communication, ownership, and practical engineering decisions. If you’re looking for a senior engineer who can build, improve, or stabilize your system, I’m happy to discuss your project.

Android, iOS, Java, .Net Development experts with extensive knowledge of US Healthcare software development and integration. Technosoft is an ISO 9001:2008 certified, IBM Advanced Business Partner, MySQL Partner & CMMI ML2 appraised, company. Healthcare Expertise Include: - HL7, FHIR, C-CDA, CCD, HIPAA, EMR, EHR, m-health, SMART on FHIR, CDS Hooks, cTakes - EPIC, Cerner, AllScripts, Kareo, Athena, Open Dental, HBOC, Siemens, Quest, EHR integration - Custom Interface, Medical Billing, Scheduling, Laboratory Integration, Athena Integration, Kareo, Redox integration Technical Expertise includes: - Python, Django, Celery Beat, Flask - iOS (Objective-C, Swift, Siri, BLE, etc) - Android - Front End Development (JQuery, Ajax, Node.js, AngularJS, ReactJS - Java/J2EE (Spring, Hibernate, JSF, Play framework, Spring Boot, Scala, etc) - .Net ASP.net, VB.net, C#, WPF, WCF, SignalR, Web Forms, Azure - Wearable Devices integration (Misfit, Fitbit, Mi-Band, etc) - Alexa/Alexa Show Skills Development - DiagFlow, Lex, Twilio, NLU, NLP, Siri, and other voice integration technologies. I am a HIMSS Certified Healthcare Security Professional and run my company Technosoft solution. We focus solely on the US healthcare market and are very well versed in HIPAA, HL7, FHIR, SMART on FHIR and other healthcare standards. We have developed video conferencing (WebRTC), EMR, prescriptions, lab orders, lab results, billing, EDI and other Healthcare Information Systems modules. We are also very well versed in fitness, wearable and biometrics devices integration. Summary: - 14+ years Healthcare IT expertise - Software solutions deployed In over one thousand US hospitals/clinics - Strong Exposure to mHealth, webRTC, HIPAA, HL7, FHIR - SEI CMMI Level 2 Appraised - Excellent Communication Skills with hundreds of completed projects. - Experts in iOS, Android, Java/J2EE, .Net, Azure development - Experienced in Agile development with Daily/Weekly SCRUM via Skype or phone availability as per your Timing. - Daily/weekly status report - References available upon request. ✅ Top-Rated - Mobile Application (iOS, iPhone, Android) Developers ✅ Top Rated - Web Application (ASP.net, Java, J2EE) Developers ✅ 5 Star Feedback ✅ 100% Job Success Score ✅ Healthcare Software Experts ✅ With Elance/Upwrok for over 17 years ✅ 10,000+ Hours clocked on Upwork with 100% Client Satisfaction

Full-Stack Engineer who builds scalable web apps that hold up in production — Angular & React on the front, Java Spring Boot & Python (Django/Flask) on the back. 100+ projects delivered, 0 missed deadlines. WHAT I BUILD → Enterprise-grade REST APIs and microservices with Java Spring Boot → Dynamic, responsive front-ends with Angular and React → Lightweight Python backends with Django and Flask → Automated web scrapers that extract, clean, and deliver structured data at scale → Database design & optimization — PostgreSQL, MySQL, MongoDB TECH STACK Frontend: Angular | React | JavaScript (ES6+) | HTML5 | CSS3 Backend: Java Spring Boot | Python Django | Flask Databases: PostgreSQL | MySQL | MongoDB Scraping: BeautifulSoup | Selenium | Scrapy | Playwright Tools: Git | REST APIs | Docker | Postman HOW I WORK I don't just write code — I ask what the feature is actually for before touching a keyboard. That means fewer revisions, cleaner architecture, and software that solves the real problem, not just the surface one. You get: ✔ Clean, documented, maintainable code ✔ Regular updates — you'll never be left wondering where things stand ✔ Honest timelines — I'd rather under promise and overdeliver ✔ A developer who thinks about your business, not just the ticket GOOD FIT FOR - SaaS platforms and internal tools - REST API development and third-party integrations - Data scraping pipelines and automation - Full-stack builds from MVP to production - Migrating or refactoring legacy systems If you're building something and need a developer who gets it done cleanly — send me the brief.

Slow backend? Unclear architecture? Need a complete web application built and deployed — without managing three different contractors? I build production-ready Java + Spring Boot backends paired with clean React frontends, deployed on AWS or GCP. Six completed Upwork contracts, three cloud certifications (AWS Solutions Architect, Oracle Java SE, GCP Associate), and a consistent track record of shipping systems that work on day one and stay maintainable at month twelve. What I deliver end-to-end: — Spring Boot REST APIs with OpenAPI documentation and proper error handling — Secure authentication: JWT, OAuth 2.0, role-based access control — PostgreSQL / MySQL database design with clean data modeling — React dashboards, admin panels, and workflow UIs wired directly to your APIs — Docker containers deployed to AWS (EC2, ECS, RDS) or GCP — CI/CD pipelines so your team ships without manual steps What makes this engagement different: I write documentation. I design APIs before I build them. I flag problems before they become your emergency. And I don't hand off code — I hand off a system you can actually operate. Best fit for: - SaaS startups that need a reliable backend with a functional frontend in 2–6 weeks - Teams replacing spreadsheets or manual workflows with internal tools and admin panels - Technical founders who want one accountable engineer, not a fragmented team My specialty is projects where the backend has to be correct — auth flows, data integrity, business logic, third-party integrations. The frontend needs to be functional and maintainable. If you need pixel-perfect animations, I'll refer you to the right person and stay focused on what I'm actually great at. Three certifications. Six contracts. Zero missed deadlines. 📩 Send a brief on your project — I respond within 4 hours (9 AM–9 PM IST). I offer a free 20-minute scoping call for projects that are a clear fit.

Are you building a product that needs scalable backend microservices, event-driven architecture, and seamless integration, without compromising on performance? Senior Java Backend Engineer with 11+ years of experience building large-scale, secure, and high-performance backend systems for US, Canada, Singapore, and India-based clients. Past clients include Stripe (OpenChannel migration), Sprouts.ai CRM platform, Orchestro AI (US logistics), and independent fintech/logistics products for US clients. Available for long-term contracts. Let's build something reliable. I specialize in Spring Boot, Microservices, Distributed Systems, and complex API integrations, and have supported both startups and enterprise teams in designing, building, and optimizing mission-critical applications from the ground up. Over the years, I have worked on a wide range of backend systems, CRM pipelines, large-scale payment ecosystems, enterprise marketplaces, data processing engines, and multi-service architectures. I enjoy solving deep backend challenges and making systems faster, cleaner, and more scalable. What I Do Best: - Java & Spring Boot Backend Development - Scalable microservices architecture - REST APIs design, development & documentation - Spring Security, OAuth2, Auth0, JWT, SSO - Optimization of slow APIs, DB queries & system performance Enterprise-Grade Integrations: - Payment gateways: Stripe, Braintree, Authorize.net, FreedomPay - CRM Systems (Salesforce, HubSpot, Zoho, custom CRMs) - 3rd-party APIs, webhooks, event-based systems - Queue systems: RabbitMQ, Kafka Database & Data Engineering: - MongoDB, MySQL, PostgreSQL - Large data processing (Java Streams, parallelization, pipeline design) - Backup/restore mechanisms - Redis caching for low-latency microservices Architect-Level Experience: - System design, technical planning, sprint leadership - Mentoring juniors & code review - Clean architecture, modular services, best practices - Cloud experience (AWS S3, RDS, CloudWatch) - Docker-based deployments Who I Usually Work With: - CTOs and founders looking for a reliable senior backend developer - Teams building SaaS platforms, CRM pipelines, enterprise apps or payment systems - Startups needing hands-on development + architecture guidance - Companies wanting to modernize, optimize, or refactor backend systems Why Clients Hire Me: - 10+ years of hands-on Java engineering - Strong ownership & independent delivery - Excellent communication and transparent progress updates - Ability to work end-to-end: architecture → development → optimization - Experience working remotely with US, Singapore & Canada clients for years I enjoy long-term collaborations and working as an extension of your engineering team. If you’re building something complex and backend-heavy, I can help you deliver it with quality and stability.

𝐈 𝐛𝐮𝐢𝐥𝐝 𝐩𝐫𝐨𝐝𝐮𝐜𝐭𝐢𝐨𝐧 𝐛𝐚𝐜𝐤𝐞𝐧𝐝, 𝐀𝐈, 𝐚𝐧𝐝 𝐝𝐚𝐭𝐚 𝐬𝐲𝐬𝐭𝐞𝐦𝐬 𝐟𝐨𝐫 𝐬𝐭𝐚𝐫𝐭𝐮𝐩𝐬 𝐚𝐧𝐝 𝐞𝐬𝐭𝐚𝐛𝐥𝐢𝐬𝐡𝐞𝐝 𝐜𝐨𝐦𝐩𝐚𝐧𝐢𝐞𝐬 𝐭𝐡𝐚𝐭 𝐧𝐞𝐞𝐝 𝐦𝐨𝐫𝐞 𝐭𝐡𝐚𝐧 𝐚 𝐩𝐫𝐨𝐭𝐨𝐭𝐲𝐩𝐞. I’m Tilek, a Senior Backend / AI / Data Platform Engineer with 15+ years of experience building SaaS products, enterprise systems, cloud infrastructure, data pipelines, AI applications, and complex integrations using Python, .NET, Java, Node.js, PostgreSQL, AWS, Azure, Kubernetes, and modern LLM tooling. 𝗠𝗼𝘀𝘁 𝗔𝗜 𝗮𝗻𝗱 𝗱𝗮𝘁𝗮 𝗽𝗿𝗼𝗱𝘂𝗰𝘁𝘀 𝗳𝗮𝗶𝗹 𝗼𝘂𝘁𝘀𝗶𝗱𝗲 𝘁𝗵𝗲 𝗺𝗼𝗱𝗲𝗹 𝗹𝗮𝘆𝗲𝗿. The real risks are fragmented data, weak backend architecture, unreliable integrations, missing observability, slow async workflows, poor security boundaries, untested AI behavior, and systems that become expensive to change after launch. I help startups and established teams turn AI, automation, data, and backend workflows into maintainable production products. 𝗪𝗛𝗔𝗧 𝗜 𝗕𝗨𝗜𝗟𝗗 • AI and LLM applications with OpenAI, Claude, RAG, LangChain, LangGraph, vector search, prompt engineering, evaluation workflows, AI agents, structured outputs, and controlled tool use • Enterprise and SaaS backend systems with Python, FastAPI, .NET/C#, Java/Spring Boot, Node.js, TypeScript, PostgreSQL, SQL Server, Redis, and API-first architecture • Data platforms for ingestion, ETL/ELT, normalization, enrichment, reconciliation, analytics, reporting, and high-volume data processing • Event-driven systems with Kafka, RabbitMQ, Airflow, queues, workers, webhooks, retries, idempotency, async processing, audit trails, and workflow orchestration • Cloud-native infrastructure across AWS and Azure with Docker, Kubernetes, Terraform, CI/CD, GitHub Actions, observability, monitoring, logging, and secure deployment practices • MLOps and AI operations including model deployment, model monitoring, evaluation pipelines, data validation, experiment tracking, workflow orchestration, and production reliability • Enterprise integrations across CRM systems, financial platforms, SaaS tools, operational software, legacy applications, third-party APIs, webhooks, and internal systems I am especially useful when a product needs to connect multiple systems, process high-volume or unreliable data, introduce AI safely, modernize an existing backend, or move from fragile workflows into a scalable SaaS platform. 𝗦𝗘𝗟𝗘𝗖𝗧𝗘𝗗 𝗣𝗥𝗢𝗗𝗨𝗖𝗧 & 𝗣𝗟𝗔𝗧𝗙𝗢𝗥𝗠 𝗘𝗫𝗣𝗘𝗥𝗜𝗘𝗡𝗖𝗘 𝐒𝐜𝐚𝐥𝐞 𝐀𝐈 Built and optimized high-volume AI data pipelines, validation workflows, model evaluation flows, and scalable ML infrastructure. 𝐒𝐞𝐜𝐥𝐞𝐚 Developed Responsible AI backend systems for model monitoring, explainability, compliance reporting, bias detection, AI governance, and enterprise ML workflows. 𝐇𝐢𝐭𝐚𝐜𝐡𝐢 𝐄𝐧𝐞𝐫𝐠𝐲 Built backend services and data-processing infrastructure for enterprise energy systems, telemetry workflows, operational analytics, cloud architecture, and scalable integrations. 𝐃𝐞𝐮𝐭𝐬𝐜𝐡𝐞 𝐁𝐚𝐧𝐤 Contributed to regulated financial systems through backend integrations, secure APIs, workflow automation, controlled data services, and compliance-sensitive architecture. 𝟏𝐍𝐂𝐄 Worked with Python, AWS, Kafka, Airflow, Kubernetes, and high-volume data pipelines for connected-device, IoT, and real-time processing workloads. 𝐃𝐞𝐯𝐞𝐫𝐮𝐬 Built secure workflow, document-processing, integration, role-based access, and backend automation capabilities for operational platforms. 𝗛𝗢𝗪 𝗜 𝗪𝗢𝗥𝗞 I start by identifying the delivery risks: data ownership, architecture boundaries, integration failure modes, scaling constraints, security requirements, AI reliability, and operational visibility. Then I build the smallest production-safe foundation that lets the product grow without expensive rewrites. 𝗕𝗲𝘀𝘁 𝗳𝗶𝘁: AI startups, SaaS platforms, RAG systems, AI agents, document AI, backend modernization, Azure/AWS cloud systems, enterprise integrations, data pipelines, CRM automation, operational products, regulated workflows, fintech, healthcare, logistics, energy, and high-volume data applications. Have a complex AI, backend, or data platform problem? Send the context and I’ll identify the highest-risk parts before implementation begins. 𝐁𝐫𝐢𝐧𝐠 𝐢𝐭 𝐭𝐨 𝐦𝐞 - 𝐈’𝐥𝐥 𝐦𝐚𝐤𝐞 𝐢𝐭 𝐩𝐫𝐨𝐝𝐮𝐜𝐭𝐢𝐨𝐧-𝐬𝐚𝐟𝐞. 𝐋𝐄𝐓'𝐒 𝐓𝐀𝐋𝐊 𝐓𝐇𝐈𝐒 𝐖𝐄𝐄𝐊. 𝗧𝗘𝗖𝗛𝗡𝗜𝗖𝗔𝗟 𝗦𝗧𝗔𝗖𝗞 Python, FastAPI, .NET, C#, Java, Spring Boot, Node.js, TypeScript, React, Next.js, PostgreSQL, SQL Server, MongoDB, Redis, Kafka, RabbitMQ, Airflow, Spark, Docker, Kubernetes, AWS, Azure, GCP, Terraform, OpenAI API, Claude API, LangChain, LangGraph, RAG, Vector Databases, Pinecone, FAISS, MLflow, REST APIs, GraphQL, Webhooks, Microservices, Event-Driven Architecture, Data Engineering, ETL, ELT, MLOps, AI Automation, AI Agents, Cloud Architecture, Enterprise Integrations, CI/CD.

👋 Hi, I’m Hasan — Senior Software Engineer & Full-Stack Developer with 5+ years of experience building secure, scalable, and high-performance systems for healthcare, finance, and retail sectors. I don’t just code — I deliver enterprise-grade solutions that automate workflows, cut costs, and drive efficiency. 💡 What I Do Best 🔐 Secure Backend Development → Java, Node.js, Express.js, REST APIs, Authentication & Authorization 🗄️ Database Design & Optimization → MSSQL, SQL Server, performance tuning for high-volume systems 🏥 ERP Systems & Automation → Full-cycle ERP modules for healthcare, finance, and trading 📊 Reporting & Data Processing → Crystal Reports, automated PDF generation, Outlook/JACOB email integration 📱 Cross-Platform Apps → Flutter + Firebase (OCR & data sync solutions) 🌟 Key Achievements ⚙️ Core Contributor to the ZAB ERP Framework, powering 200+ reports across 20+ industries 💳 Automated BRAC Bank’s Financial Reconciliation with secure Express.js APIs using RSA + SHA-256 🚑 Hospital ERP (United Hospital) → Cut report generation time from 10 minutes → under 1 minute with multithreading + Crystal Reports 🔄 Data Sync Automation → Designed robust solutions to handle 10K+ daily transactions with accuracy & speed 📱 Product Scanner Mobile App (R&D) → Built Flutter OCR app with Firebase integration for retail product digitization 🔧 Tech Stack at a Glance ☕ Java, Java Servlets, JSP ⚡ Node.js, Express.js 💾 SQL Server, Database Optimization 🎨 React, jQuery, UI Components 📑 Crystal Reports, Report Automation 📱 Flutter, Firebase, ML Kit OCR 🔒 RSA/SHA-256 Secure APIs 🤝 Why Clients Hire Me ✔️ 5+ years delivering enterprise-grade solutions that actually solve business problems ✔️ Strong mix of backend architecture, API integrations, and database engineering ✔️ Experience across healthcare, banking, trading, and retail domains ✔️ Focused on security, scalability, and performance — not just “getting it to work” ✔️ Clear communicator, reliable, and results-driven 📩 Let’s Work Together Whether you need: 🔹 A robust ERP module 🔹 A secure API integration 🔹 Database optimization 🔹 Or a custom backend workflow 👉 I’ll bring deep technical expertise + business-focused solutions to your project. Let’s build something impactful 🚀.

Hello! I'm Jalal, a passionate and seasoned Android App Developer with over 5 years of hands-on experience in creating innovative, user-centric mobile applications. My expertise lies in leveraging Kotlin and Java to build robust, scalable, and efficient apps that not only meet but exceed client expectations. Comprehensive Experience - Developed and deployed 10+ Android apps across various domains including e-commerce, finance, healthcare, entertainment and phone diagnostics. Technical Proficiency - Expert in Kotlin and Java, with extensive knowledge of Android SDK, Jetpack components, and modern architectural patterns like MVP, MVC, MVVM and MVI. UI/UX Focused - Strong eye for design and usability, ensuring that each app delivers an intuitive and engaging user experience. API Integration - Proficient in RESTful API and third-party library integration (Retrofit, Glide, Firebase, Google Map, Mapbox, FFMPEG and other libraries). Performance Optimization - Skilled in optimizing app performance and memory usage, ensuring smooth and fast user interactions. Quality Assurance - Committed to maintaining high code quality through rigorous testing and adherence to best practices. What I Can Offer Custom Android App Development: Tailored solutions to bring your unique app ideas to life, from concept to deployment. Maintenance & Upgrades: Ongoing support to keep your app updated with the latest features and improvements. Code Review & Optimization: Detailed analysis and enhancement of existing codebases to boost performance and maintainability. Bug Fixing & Troubleshooting: Quick and effective resolution of any issues to ensure your app runs flawlessly. Notable Projects: E-commerce Platform: Developed a feature-rich shopping app with real-time inventory updates, secure payment gateway integration, and personalized recommendations. Project names are Vital Sales Pro, Sufi Sales Pro. Healthcare App: Created a comprehensive health tracking application that includes appointment scheduling, medication reminders, and telehealth services. Project names are AlphaCare, Inteli-Health, Family Doc. Diagnostics App: Created a robust, smart and user friendly phone diagnostic app. Which helps the client to diagnose the mobile phone in minutes and ensure that all the components like Speakers, Microphones, Sensors, Storage and other functionalities are working perfectly. Project names are PhoneCheck, DeviceWork & MoboCheck. Core Skills - My core skill set includes Kotlin, Java, Android SDK, Jetpack Compose, MVP, MVC, MVVM, MVI, RESTful APIs, Firebase, Retrofit, Glide, Dagger2, Hilt, UI/UX Design, Performance Optimization, Quality Assurance. Availability: I am available for Full-Time, Part-Time and Project Based. Let's Connect: I am dedicated to helping you achieve your app development goals. Let's discuss how I can bring your project to life with precision and excellence. Feel free to reach out, and let's get started on your next successful Android app!