I help companies move beyond AI demos to production-ready systems. With 15+ years in high-performance Node, Java backend and 3+ years in applied AI, I specialize in building scalable, reliable AI systems that actually work in real-world environments. What I deliver: • LLM & RAG Systems • Production-grade pipelines using pgvector, GraphRAG, and FastAPI • Secure, grounded AI (no hallucination-heavy prototypes) • AI Agents & Automation • OpenTelemetry, Grafana, LangFuse • Multi-step workflows using LangChain and agent orchestration • Business process automation using LLM reasoning • Computer Vision • Real-time systems using YOLO and CNNs • Retail analytics, tracking, and behavior insights • Backend + AI Integration • Spring Boot, Kafka, Microservices • High-concurrency systems with AI embedded at scale Why clients hire me: • I don’t build AI demos — I build systems that scale in production • Strong focus on performance, security, and reliability • Ability to connect AI with existing enterprise infrastructure

Hi, I'm Hasitha, a software engineer having extensive experience of over 7 years in software and web development, server administration and also a strong communicator with the ability to convey ideas clearly with an emphasis on client satisfaction. My specialized areas are as follows. ◈ Server-related tasks ✅ Troubleshooting issues related to web servers (Apache, NGINX). ✅ Installation/renewal of SSL certificates. ✅ Troubleshooting Linux server-related issues. ✅ Configuration of LAMP/LEMP stack. ✅ Fixing 401, 403, 404, 502, and 503 HTTP errors. ✅ Configuration of Webmin, Virtualmin, WHM, and cPanel. ✅ Troubleshoot SSH access-related issues. ◈ WordPress websites ✅ Migration of WordPress websites from one hosting to another ✅ Troubleshooting WordPress website-related issues (Critical errors, outgoing emails not working, etc.). ✅ Set up SMTP email configurations. ✅ WordPress core, themes, and plugin updates. ✅ Payment gateway integrations. ◈ Email related configurations ✅ Google Workspace email set up. ✅ SMTP configurations for different web applications. ✅ Configuration of third-party SMTP providers such as AWS SES, SendGrid. ◈ DNS related tasks ✅ Configuring DNS (adding/modifying DNS records, updating nameservers) in different domain providers (GoDaddy, Namecheap, Google Domains, Bluehost, DreamHost, etc). ◈ Websites/Web application development ✅ Fix errors related to websites/web applications built using HTML, CSS, JavaScript, PHP, and MySQL. ✅ Build web applications using the PHP Laravel framework. ✅ Development of backend APIs using Java Spring Boot framework. ✅ Third party API integrations. ◈ Infrastructure management in different Cloud Computing Platforms ✅ Amazon Web Services (AWS) ✅ DigitalOcean ✅ Google Cloud Platform (GCP) ✅ Microsoft Azure If you're looking for a dedicated and experienced developer/server admin who can deliver high-quality code and drive successful project outcomes, I'd love to chat with you. Let's work together to turn your vision into reality!

🏆 𝗧𝗢𝗣 𝗥𝗔𝗧𝗘𝗗 𝗣𝗟𝗨𝗦 🏆 ✅ Mobile App Developer 7+ years of experience ✅ SaaS Mobile App Developer 5+ years ✅ 35 mobile app development jobs completed successfully ✅ Android and iOS Mobile Expert ✅ Built 27+ UX-first Mobile App development jobs for 22 companies ✅ On-Time and Cost-Effective Delivery ✅ Future-Proof Solutions Showing a Minimum 41% ROI ✅ 4354 mobile app development hours on Upwork and still counting ✅ 100% Job Success in mobile app development (Client Satisfaction Ratio) ✅ 98% of Clients Recommended working with me ✅ 80% Long-term Repeat Clients ✅ 7+ years of experience in mobile app development, 6 years experience in iOS mobile app development, 7 years experience in Swift and Kotlin, 4 years experience in Flutter, React Native, 2 years experience in KMM, KMP Full stack mobile app developer and mobile app UI UX designer with 7+ years of experience in Mobile App Development, specializing in iOS, Swift, Android, Kotlin, KMM, Kotlin Mutliplatform / KMP, React Native, and Flutter. I have successfully delivered 120+ mobile applications in different roles as mobile app developer, flutter app developer, flutter full stack developer, flutter flow, mobile app design, mobile ui ux designer, swift ios developer, android developer, kotlin developer, react native developer, mobile game developer achieving a 5-star rating on Upwork and helping clients scale their businesses with high-performance solutions. Apart from mobile app development, I specialize in Mobile App Design for both iOS and Android, as well as Web App Design for SaaS platforms. My expertise extends to Interaction Design, User Flow Design, and creating seamless User Experience (UX Design) and User Interface (UI Design). I follow a Design Thinking approach, ensuring every solution is user-centered and problem-solving. My process includes UI/UX Wireframing, Prototyping, and building Style Guides or UI-kits for consistent branding. I perform Design Audits and Design QA to maintain high standards across all projects. 🛠️ Design Tools: My designs come to life through powerful tools like Figma, Zeplin, and InVision for prototyping and collaboration. I leverage Adobe Illustrator, Adobe Photoshop, and Adobe XD for detailed visual design. For complex wireframes and flow mapping, I turn to Axure, Sketch, and Balsamiq. I also use Miro and Abstract for brainstorming and version control, while project communication and management happen in Slack and Jira. Our Expertise at a Glance • Mobile App Development: Android, iOS, & Cross-Platform App Development using Java, Kotlin, Swift, Objective C, Flutter, and more. • Website and Full Stack Development: Crafting seamless back-end experiences with .Net, Python, Java, Javascript, React.js, Angular.js, Node.js, MERN, MongoDB, PHP, etc. • Logo & UI/UX Design: Bringing your ideas to life with Adobe XD, Photoshop, Sketch, Figma, etc. • End-to-End Solutions: From logo design, UI/UX development, workflow setup, testing to deployment in app stores, we've got it all covered. We do not use v0.dev lovable.app CursorAI, Cursor, Windsurf, Trae, GitHub Copilot, Tabnine, Qodo, Devin AI, and AutoDev for speed up coding, we know other methods to do it efficiently. We offer a comprehensive range of development services across mobile, web, and cloud platforms. Our mobile app development expertise includes building Android and iOS applications using technologies such as Flutter, Swift, Objective-C, React Native, and Xamarin, optimized for both smartphones and tablets with a focus on cross-platform compatibility. In website and full stack development, we work with .NET technologies, including full stack .NET development, .NET Core, and Python with Django. Our team is experienced in developing both backend systems and user-friendly, responsive web interfaces, as well as working with various CMS platforms. Our DevOps and DevSecOps capabilities cover cloud infrastructure and automation, leveraging tools like AWS, Azure, Docker, Kubernetes, GitLab CI, Ansible, and Terraform to build secure and scalable deployment environments. We also build cross-platform and web applications using frameworks like Three.js and design tools such as Webflow, creating visually engaging and functional user experiences across devices. Additionally, we are well-versed in integration and automation tools, including WebSockets, data integration, the ABP Framework, Discord API, and Autotask, allowing us to create seamless connectivity and workflow automation between systems. Talent Good Knowledge, Talented, Experienced, Skilled, Strong Experience, Proven Experience, Agency, Team, Company, Specialist, Proven Track Record, Strong Background, Write Clean Code, Deep Expertise, Bring to Life, Cross-platform, Attention to Detail, Long Term. ⚡️ AVAILABLE FOR NEW PROJECTS ⚠️ Press Invite Button on my page and let's talk.

I build production-grade web applications, APIs, and ERP/CRM systems — from architecture to deployment. My work spans full-stack development, database design, Telegram bot backends, and Odoo customization, with recent projects involving AI integration, ML pipelines, and encrypted infrastructure on AWS. What I deliver Full-stack web applications (React/TypeScript frontend + Laravel or Python backend) REST API design, OAuth 2.0 + PKCE, role-based access control Database architecture and optimization — PostgreSQL, MySQL Odoo ERP/CRM: custom modules, QWeb templates, workflow automation, Telegram bot integrations (v16–v18) Telegram bots with backend logic and database integration AI/ML feature integration — model deployment, automation pipelines, intelligent assistants Server setup and DevOps — AWS EC2, Docker, Nginx, Linux administration Recent projects AI CRM Analytics Platform (SaaS, multi-tenant) Built a production-ready AI-powered CRM analytics platform from scratch. Sales teams connect HubSpot, Salesforce, or Pipedrive and query their live pipeline data in plain English — the AI responds using synced, up-to-date CRM data. OAuth 2.0 + PKCE integrations for 3 CRM providers Auto-sync every 15 min via BullMQ/Redis job queue GPT-4o query layer with intent classification and self-learning user memory Full CRM dashboard: contacts, deals, pipeline kanban, deal canvas, calendar Multi-tenant architecture on Supabase/PostgreSQL, deployed on Railway Encrypted CRM on AWS Secure hacker/terminal-aesthetic CRM with field-level encryption (PBKDF2-HMAC-SHA256), LUKS2-encrypted EBS volume, JWT session revocation with IP binding, Dead Man's Switch, and Twilio SMS/voice integration — deployed on AWS EC2. Odoo Custom Modules (v18) Telegram Bot API integration, custom QWeb print templates, insurance broker management module — built as portfolio deliverables with full documentation. Tech stack Backend: Python, PHP (Laravel), C#, Java Frontend: React, TypeScript, JavaScript, HTML/CSS Databases: PostgreSQL, MySQL Infrastructure: AWS EC2, Docker, Nginx, Linux ERP/CRM: Odoo v16–v19 Other: Telegram Bot API, BullMQ/Redis, GPT-4o, ML model integration, REST APIs Working style I take on projects where technical decisions matter — where someone needs a developer who understands business logic, can own the architecture, and delivers without hand-holding. I prefer clearly scoped work and direct communication. Available for long-term collaboration or well-defined project contracts.

My goal is not just to write code, but to provide peace of mind. By integrating security into the development lifecycle from day one, I help my clients avoid costly breaches and build long-term trust with their users. I am a highly experienced Senior Full-Stack Developer with a specialized focus on Cybersecurity. With over a decade of experience in safeguarding digital assets and building robust web applications, I offer a unique blend of development prowess and security-first engineering. My expertise spans modern frameworks like Laravel, Vue.js, and React, coupled with a deep understanding of secure coding practices, system hardening, and data integrity. I provide clients with the confidence that their digital solutions are not only high-performing and scalable but also inherently secure against evolving threats, delivering solutions that are reliable, maintainable, and protected. As the Founder & Lead Developer of SolidScripts, I have established and grown a successful tech consulting firm, serving over 10+ international clients. My work, combined with my role as Senior Cybersecurity Developer & Full-Stack Lead at SharkGate Limited since 2016, has equipped me with extensive experience in: * **Full-Stack Web Development:** Proficient in PHP (Laravel, CakePHP), JavaScript (Vue.js, React, Node.js), MySQL, PostgreSQL, and modern front-end technologies (Tailwind CSS, TypeScript). * **Cybersecurity & System Hardening:** Over 10 years of experience in web application security, malware analysis, vulnerability assessment, and implementing robust security measures (e.g., OWASP best practices, secure API integration, data protection). * **API & System Integration:** Expert in designing and implementing secure RESTful APIs, integrating third-party services (CRM, payment gateways, credit-pull APIs), and ensuring seamless data flow with retry logic and error handling. * **Recent Project Contributions:** Led development for the MomGov Assistance platform, contributed to the Tagdai ecosystem, developed the LaFisio Practice Management System (PMS/ERP) and mobile app, and built the Mandyjumi e-commerce platform. I maintain a 'Top Rated Plus' status on Upwork with a 100% Job Success Score, reflecting my commitment to delivering high-quality, client-satisfying results.

👋 Hello! I'm results-driven Web Developer & Digital Solutions Architect with a passion for crafting high-performing, visually stunning, and scalable web solutions. With more than 10 years of experience, I specialize in transforming ideas into powerful digital experiences that drive business growth. 💼 Services I Offer 🔹 Custom Web Development – I create fast, responsive, and user-friendly websites that align with your brand and business goals. 🔹 E-Commerce Development – From Shopify to WooCommerce, I build seamless online stores with secure payment integrations. 🔹 Business-Centric Web Solutions – I design and develop tailored web solutions that help businesses scale efficiently. 🔹 UI/UX Design & Optimization – I enhance user experiences with intuitive and engaging designs that boost conversion rates. 🔹 Performance Optimization & SEO – I ensure high-speed performance and SEO-friendly structures for better rankings. 🚀 Skills & Expertise ✅ Frontend Development - HTML5, CSS3, JavaScript (ES6+) - React.js, Vue.js, Angular - Tailwind CSS, Bootstrap ✅ Backend Development - Node.js, Express.js, PHP - Laravel, Django, Ruby on Rails - RESTful & GraphQL APIs ✅ E-Commerce Solutions - Shopify Development & Customization - WooCommerce & WordPress - Magento & Custom E-Commerce Platforms ✅ Database Management - MySQL, PostgreSQL, MongoDB, Firebase ✅ Cloud & DevOps - AWS, Google Cloud, Azure - Docker, Kubernetes, CI/CD Pipelines ✅ CMS & No-Code Development - WordPress, Webflow, Wix - Headless CMS (Strapi, Contentful) 💡 Why Work With Me? ✔️ Custom Solutions Tailored to Your Needs ✔️ Scalable & Secure Development Practices ✔️ Mobile-First & SEO-Optimized Websites ✔️ Transparent Communication & On-Time Delivery Let’s build something amazing together! 🚀 📩 Get in touch today

Some developers wait for tasks. I take responsibility for outcomes and ship working products. If your app is delayed, unstable, half-built, or handled by too many people without ownership — that’s exactly the kind of situation I step into and fix. I focus on turning ideas and messy builds into stable, launch-ready web, mobile, and AI-enabled products. I’m a Top-Rated Full-Stack Developer with 2000+ proven working hours, $30K+ client investment, and a 100% success score — which means clients don’t just hire me, they trust me to deliver production systems that actually run in the real world. Clients usually come to me when: • their previous developer couldn’t finish the build • the backend works but doesn’t scale or stay stable • the mobile app exists but feels unreliable • they need AI features added properly, not experimentally • they want one developer who can handle architecture → build → deployment What makes me different is simple: I don’t behave like a task-based freelancer. I work like a technical partner. I question weak plans, fix risky architecture early, and build systems meant to survive after launch — not just pass a demo. Core strengths: • End-to-end SaaS & web platform development • Mobile apps connected to real backend systems • Clean, scalable APIs & database design • Stabilizing or completing unfinished projects • AI integrations (OpenAI / ChatGPT / automation workflows) • Cloud-ready deployments with performance focus If I accept your project, it means I’m confident it can be delivered properly. I prefer serious builds, clear communication, and clients who want the job done right the first time. If that’s what you need — send an invite and let’s discuss your product.

I'm a senior full-stack engineer with 𝟏𝟓+ 𝐲𝐞𝐚𝐫𝐬 of experience, including nearly a decade building at scale for 𝐀𝐩𝐩𝐥𝐞 and 𝐀𝐦𝐚𝐳𝐨𝐧. Unlike most generalists, I also build production-grade AI features. That combination is rare, and it's why clients hire me. Whether you need a scalable web application, a complex backend system, or AI/LLM capabilities woven into an existing product, I can own it end-to-end, architecture through deployment, frontend through infrastructure. 𝐅𝐮𝐥𝐥-𝐒𝐭𝐚𝐜𝐤 𝐃𝐞𝐯𝐞𝐥𝐨𝐩𝐦𝐞𝐧𝐭 React + TypeScript frontends with clean component architecture, real-time updates, secure auth flows, and performance tuned for real users. Java backends (Spring Boot, WebFlux, reactive systems), Node.js/TypeScript APIs, REST & GraphQL (Apollo), microservices design, and distributed data layers across DynamoDB, SQL, and NoSQL. I build applications that are testable, maintainable, and designed for scale from day one, not patched together after the fact. 𝐀𝐈 & 𝐋𝐋𝐌 𝐈𝐧𝐭𝐞𝐠𝐫𝐚𝐭𝐢𝐨𝐧 This is where I pull ahead. When a project calls for intelligence, a chatbot, a knowledge assistant, a RAG pipeline, automated workflows, I don't hand it off to a separate AI contractor. I build it myself, integrated cleanly into the same stack. GPT/Gemini integrations, retrieval-augmented generation, context-aware chat systems, prompt pipeline design, structured output with validation, and hallucination mitigation. AI that's engineered into the product, not bolted on. 𝐂𝐥𝐨𝐮𝐝 & 𝐈𝐧𝐟𝐫𝐚𝐬𝐭𝐫𝐮𝐜𝐭𝐮𝐫𝐞 AWS-native architectures, Kubernetes, Helm, Docker, CI/CD pipelines, and production observability with Prometheus, Grafana, and Datadog. SLO-driven monitoring and reliable deployment workflows. Features don't matter if they're not up, I make sure they stay up. 𝐖𝐡𝐲 𝐜𝐥𝐢𝐞𝐧𝐭𝐬 𝐜𝐡𝐨𝐨𝐬𝐞 𝐦𝐞 𝐨𝐯𝐞𝐫 𝐨𝐭𝐡𝐞𝐫 𝐬𝐞𝐧𝐢𝐨𝐫 𝐝𝐞𝐯𝐬:: Most full-stack engineers can't touch AI. Most AI freelancers can't architect real systems. I do both, and I've done it inside two of the most demanding engineering organizations in the world. 𝐒𝐞𝐥𝐞𝐜𝐭𝐞𝐝 𝐫𝐞𝐬𝐮𝐥𝐭𝐬: At Apple, built a React + TypeScript platform for large-scale test execution, developed an AI-powered internal support chatbot, and improved system observability, cutting incident resolution time by 30% and reducing deployment time by 30%. At Amazon, migrated critical systems from Oracle to DynamoDB, reduced infrastructure maintenance by 20%, designed resilient AWS-native services, and helped launch Amazon in new international markets. 𝐈'𝐦 𝐭𝐡𝐞 𝐫𝐢𝐠𝐡𝐭 𝐟𝐢𝐭 𝐢𝐟 𝐲𝐨𝐮 𝐧𝐞𝐞𝐝: A senior engineer who can own your product end-to-end. A full-stack application built properly, architecture-first, scalable, maintainable. AI or LLM features added to an existing product without breaking what's already there. A complex backend, a polished frontend, or both. A technical partner who ships production systems, not prototypes. 𝐇𝐨𝐰 𝐈 𝐰𝐨𝐫𝐤: Architecture-first. MVP fast, production-ready fast. Clean, testable code. Clear communication. Built for scale from day one. I don't build throwaway demos. I build systems that survive production, with or without AI. Let's talk.

Product Delivery Expert | Mobile & Web Apps | Swift, Kotlin, Flutter, React Native, Python, Java, PHP ✈️ I help startups and businesses design, build, and launch AI-powered products fast What I deliver: - AI-powered mobile and web applications - MVP development for startups - End-to-end product delivery - Native iOS apps: Swift, SwiftUI - Native Android apps: Kotlin, Java - Cross-platform apps: Flutter, React Native - Backend systems and APIs: Python, PHP, Java - SaaS platforms and automation tools - UX/UI design, wireframes, product flows - Legacy code improvement and app optimization - App Store & Google Play deployment - Post-launch support, scaling, and ASO consulting Experience across: AI products, SaaS, healthcare, logistics, marketplaces, geolocation apps, fintech, and on-demand platforms. Key results: 🏆 200+ apps launched on App Store and Google Play 🏆 Michelin-awarded logistics mobile app 🏆 Improved user retention by 10% within 2 months 🏆 Delivered products for startups and SMBs across multiple industries 🏆 7+ years building and shipping digital products How I work: I focus on fast execution, clear communication, and business-oriented delivery. I can join at any stage of the project, whether you need product validation, MVP delivery, scaling, redesign, or technical leadership. My process includes: - Product discovery and planning - Transparent project management with Jira - UX/UI focused product design - Scalable development architecture - QA testing and deployment - Long-term maintenance and growth support About me: I combine technical execution with product thinking. Beyond coding, I help clients make better product decisions, reduce delivery risks, and move from idea to launch efficiently If you need a reliable AI product partner who can take ownership and deliver production-ready applications, let’s connect. Keywords: AI Development, AI Agents, AI Chatbots, Generative AI, AI SaaS, AI Automation, Mobile App Development, iOS Development, Android Development, Swift, SwiftUI, Kotlin, Flutter, React Native, Python, SaaS Development, MVP Development, UX/UI Design, Product Design, API Integration, Firebase, OpenAI API, ChatGPT Integration, Backend Development, Startup Apps, App Store Deployment, Google Play Publishing, Healthcare Apps, Logistics Apps, Fintech Apps, Marketplace Apps, Geolocation Services, Cross-Platform Apps, Product Management, Agile, Jira, ASO, Scalable Architecture

Hi, I’m Serghei. I help startups, agencies, and businesses build production-ready web and mobile applications, from idea and architecture to backend development, deployment, and ongoing improvements. I specialize in Laravel, custom PHP systems, REST APIs, SaaS platforms, CRM systems, dashboards, and React Native mobile apps with Expo. I can help you with: • Building web applications from scratch • Developing backend systems and APIs • Creating SaaS platforms and subscription systems • Integrating Stripe payments and third-party services • Building React Native mobile apps • Improving, fixing, or extending existing projects • Creating clean and fast landing pages when needed Tech stack: • Laravel / PHP • MySQL / PostgreSQL • REST APIs • React Native / Expo • Stripe • SaaS architecture • CRM and dashboard development I’m comfortable working even when there is no full specification or design yet. I can help clarify the idea, suggest the right technical approach, and turn it into a working product. Whether you need a new product built from scratch or improvements to an existing system, I can quickly understand the requirements and deliver reliable, clean, and maintainable solutions.