I'm a senior software engineer with extensive experience building scalable APIs, cloud platforms, and mobile applications used by billions of users. I’ve worked on production systems at companies like Meta Platforms and T-Mobile, and I bring that same engineering discipline and reliability to every client project. Throughout my career I’ve designed and built backend systems, microservices, and mobile applications that power real products. I specialize in building software that is not only functional but also scalable, maintainable, and ready for long-term growth. In addition to enterprise experience, I’ve also worked extensively with startups and small teams, helping them move quickly from concept to working software. I understand the balance between moving fast and building systems that won’t break as your product grows. Whether you're launching a new product, building an MVP, integrating APIs, or improving an existing platform, I focus on delivering solutions that are reliable, efficient, and designed with best engineering practices. What I Can Help You Build Backend & API Development • REST APIs and microservices • Backend platforms and system architecture • Secure authentication systems (OAuth, Cognito, etc.) • Third-party API integrations • High-performance backend services Cloud & Infrastructure • AWS architecture and deployment • Serverless systems (Lambda, event-driven systems) • Scalable cloud platforms • Database design and optimization • DevOps and deployment pipelines Mobile Applications • Cross-platform mobile apps using Flutter • API integration for mobile apps • Authentication, file uploads, and backend communication • Performance optimization and debugging Technologies I Work With Python • C# • Flutter • REST APIs • AWS • Serverless • PostgreSQL • MongoDB • Microservices • Cloud Architecture • Docker • Event-Driven Systems Recent Types of Projects • Designing backend APIs that support mobile applications • Building serverless cloud systems on AWS • Creating MVP platforms for startups • Integrating complex third-party APIs • Optimizing backend performance and reliability • Debugging and stabilizing production systems Why Clients Work With Me Clients hire me because I bring both enterprise engineering experience and startup speed. I understand how to quickly identify the core problem and deliver solutions that work in production. You can expect: • Clear and professional communication • Clean, maintainable code • Thoughtful system design • Reliable delivery and follow-through I treat every project like a product that will need to scale and evolve over time, not just a quick patch or temporary solution. Education Master’s Degree – Computer Science Bachelor’s Degree – Computer Science If you're looking for an experienced engineer who can help you build, scale, or improve your software, I'd be happy to learn more about your project.

My love for virtual reality is what motivated me to pursue a skill in game development. I love VR, but also develop for PC, mobile, and web. I prefer multiplayer games, so I made a point of learning Photon Engines PUN 2 pretty early on in my game dev journey.

My name is Matthias, I'm a software developer with 10+ years of experience, and since 2019 I've focused on Python and AI. I build LLM apps, generative image tools, and the backends that run them. I've been working with Stable Diffusion since the day it launched, and I keep up with what's current. These days that means Flux.2 and Z-Image for image generation, GPT-5.5 and open models like Mistral for text. I've shipped real products with this stuff, not just demos. Some things I've built: a children's story generator that writes and illustrates stories, a tool that summarizes YouTube videos, an app that auto-illustrates articles, and a roleplay app for practicing social skills running on a fine-tuned Mistral model. Every one went from idea to live and deployed. What I'm good at is taking an AI model and turning it into something that actually works for users. GPT integration, a custom image pipeline, a fine-tuned model, or a full Python backend with the API and server setup behind it. I can also build the iOS or Mac app on top if you need it, since that's where I started. What I can build for you: - LLM apps and chatbots (GPT-5.5, Mistral, local models) - Image generation pipelines (Flux, Z-Image, Stable Diffusion, fine-tuning) - Python backends and APIs (FastAPI, Flask, Django) - Fine-tuning, RAG, and LangChain setups - Web scraping and data extraction - Deployment on Docker, Linux, AWS, GCP Core skills: - Languages: Python, JavaScript, Swift, Objective-C - AI/ML: GPT-5.5 API, Flux, Z-Image, Stable Diffusion, fine-tuning, LangChain, PyTorch - Backend: FastAPI, Flask, Django, PostgreSQL, Redis, Celery - Infra: Docker, Linux, AWS, GCP, Git, Nginx Why hire me: I finish what I start. Everything above is deployed and working. I've co-founded a few startups so I think about the product and the user, not just the code. And I'm easy to work with, I communicate clearly and hit deadlines. Let's talk about your project.

I'm Melissa Hong, the founder of OMG Code, a tech company specialized in web and app development. I'm honored to be a Top Rated Plus freelancer in Upwork's Customer Advocacy program, boasting a flawless Job Success Rate and holding the prestigious Top Rated Plus Badge. Additionally, I proudly serve as a Wix Community Leader and a Velo Certified Official Wix Legend Partner, bringing extensive experience in front-end and back-end web and mobile design and development. Throughout my career, I have achieved significant milestones. I have earned over $400,000 in earnings, received more than 90 five-star reviews, and successfully completed over 150 jobs, totaling an impressive 4500 hours of work. Recognized by Upwork, I have been named among the "Top 15 Wix Specialists," as well as the "27 Best Javascript Developers," "Top 27 Best Freelance PHP Developers," "Top 8 iPhone App Developers," and "Top 11 Android App Developers" for hire near San Francisco. In addition to these achievements, I have been invited as a speaker for respected organizations such as Wix, Upwork, Women Who Code, and Coding Dojo. Furthermore, I have contributed as an instructor and blogger for Udacity, collaborating closely with Stanford University. Follow your dreams, don't give up, and believe in yourself!

Hello! I'm Lucas. I am a highly experienced software developer who specializes in app and mobile game development, and I have been building apps, games, websites, and other software for over 15 years. I graduated with honors from the University of California: Santa Cruz with a degree in Computer Science (with a focus in game design). Upon graduating, I worked as an engineer for Intel for several years. After that, I decided to become an independent developer and have managed my own app development company for the past 9 years. I have developed and released several popular apps and games of my own design for Android and iOS, and have worked on countless projects on a freelance basis. These projects have ranged from small bug fixes/optimizations, to prototype designs of new games, apps and utilities, to fully functional apps for small studios and large corporations alike. Though I have focused expertise in mobile app and game developments, I am also quite skilled in related fields such as UI/UX design, web development, backend programming, and technical art creation (Adobe Photoshop/Illustrator/etc.). I am constantly learning new skills and work hard to keep my knowledge up to date with new frameworks, platforms, tools, and best practices. I have recently embraced agentic AI code development to speed up production time, but I never "vibe-code" or accept code changes without reviewing and understanding what has changed. AI is a valuable tool, but not a replacement for a professional developer. Don't waste your money on a bloated production team, and don't risk your dream project with an inexperienced or inattentive freelancer. Regardless of the needs of your project, big or small- prototype or production-ready, I'm your dev. Let's build it!

I build native iOS and Android applications that work in the real world, in the field, offline, in complex physical environments where most mobile solutions fall apart. My focus is on technically demanding work: augmented reality and spatial computing, LiDAR-based 3D reconstruction and site scanning, RoomPlan-based room and space capture, GIS and GNSS field data collection, BLE and IoT device integration, and AI/ML features that actually ship. Not demos, production systems. I'm the founder of Quality Wolves, a senior-only engineering team. Everyone on the team has owned full project cycles and made architectural decisions. We take ownership of the technical scope, surface what matters, and keep things moving. You stay focused on your product, we handle the build. What I build: Native Mobile: Swift, SwiftUI, Kotlin, full-cycle iOS & Android development, App Store and Google Play delivery AR / Spatial Computing: ARKit, ARCore, RealityKit, RoomPlan, LiDAR scanning, point cloud processing, 3D reconstruction, Apple Vision Pro. GIS & Field Data: GNSS/RTK integration, offline-first architecture, geospatial data pipelines, custom map layers, QGIS compatibility AI & ML: LLM integration, computer vision, NLP, on-device inference with Core ML and TensorFlow Lite, OpenAI and custom model pipelines, TTS/STT Connectivity: BLE pairing flows, LoRa, IoT sensor integration, background sync, beacon tracking Our senior engineers use AI tools deliberately, not as a substitute for judgment, which means faster delivery without trading speed for technical debt. Good fit if you: Need someone who operates independently without hand-holding Are building something with real operational complexity Have been burned by teams that shipped demos and called it done Describe the problem you're trying to solve, send a message, and let's talk specifics.

I design and deliver production-grade real-time communication systems including video conferencing, live streaming, VoIP, and messaging platforms that must perform reliably at scale. With over 15 years of experience in WebRTC and telecom technologies, I have built solutions ranging from one-to-one calling apps to large multiuser collaboration and broadcasting systems across mobile, web, and backend infrastructure. What I can help you build or fix: ✔ Low-latency audio and video platforms using WebRTC, LiveKit, Janus, or custom stacks ✔ Video conferencing and virtual collaboration applications ✔ VoIP and SIP integrations ✔ Live streaming and broadcasting systems ✔ Real-time messaging platforms and backends ✔ Cross-platform mobile apps for iOS and Android ✔ Debugging complex media issues such as quality problems, device failures, sync issues, and scaling challenges Technical expertise: • Protocols: WebRTC, SIP, RTP, SRTP, RTSP, RTMP, XMPP, HLS • Networking: UDP, TCP, IP, NAT traversal, media routing • Platforms: iOS, Android, Web, Node.js, Go, Python backends • Infrastructure: scalable real-time architectures • Performance optimization and reliability engineering • Twilio, Telnyx, DeepGram, ElevenLabs I have helped startups launch communication products from scratch and assisted established teams in stabilizing systems already running in production. If your project involves real-time audio, video, or messaging, there is a high chance I have solved a similar challenge before. Let’s build a system that works flawlessly in production, not just in demos.

✅ 12+ Years of Hands-on Experience ✅ Strategic Architect With Hands-On Coding Expertise ✅ Quick Turnaround Time Without Compromising Quality ✅ Excellent Communication & Availability ✅ Specialist in Shopify, WordPress & Custom Web Development Hi there 👋 I’m a Senior Full Stack Web Developer with years of experience helping startups, e-commerce brands, and enterprises build powerful, high-converting digital solutions. I specialize in crafting: 🚀 Shopify Stores that are optimized for sales & conversions 🎯 CRO-focused Websites that turn visitors into customers 🌐 Custom WordPress Development tailored to your brand ⚡ Full-Stack Web Solutions that are fast, scalable, and user-friendly Unlike typical developers, I don’t just “code”, I work as your technology partner, ensuring every stage of your project (from idea to launch) delivers real business impact. Why Work With Me? ⭐ Trusted by global clients, from startups to enterprise-level businesses ⭐ Strong background in building e-commerce stores that drive measurable growth ⭐ Deep expertise in conversion optimization for better ROI ⭐ Clear communication, reliable delivery, and long-term support Accomplishments: 🌟 Delivered 150+ projects across Shopify, WordPress, and Full Stack development 🌟 Helped e-commerce brands scale their sales and revenue with optimized websites 🌟 Recognized on Upwork for consistent client satisfaction & long-term partnerships Core Services: 🔹 Shopify Development (Themes, Stores, Customization, CRO) 🔹 WordPress Development (Custom Sites, WooCommerce, Plugins) 🔹 Full-Stack Development (Frontend + Backend Solutions) 🔹 Responsive Web Design (Modern, SEO-friendly, Mobile-first) 🔹 Ongoing Maintenance & Performance Optimization Tech Stack: * Frontend: React.js, Vue.js, JavaScript, TypeScript, HTML, CSS, Tailwind, jQuery * Backend: Node.js, PHP, Laravel, Python, Django * CMS / E-Commerce: Shopify, WordPress, WooCommerce, Webflow, Wix * Databases: MySQL, MongoDB, PostgreSQL * APIs & Integrations: REST, GraphQL, Payment Gateways, Third-Party Tools * DevOps & Hosting: AWS, Docker, Git, GitHub, Bitbucket

With over 10 years of experience in developing mobile apps for Android and Java Server-side, I possess strong skills and concepts in mobile app and server-side integration, including REST web services. Moreover, I have a deep understanding of Mobile Device Management (MDM) protocols and platforms, specifically Apple, Google, and Windows. I have developed multiple MDM-based apps for schools and enterprises, both mobile and server-side, while managing technical and development efforts as well as teams. In addition to my work with larger organizations, I have also collaborated with several start-ups, providing technical expertise to help them achieve their goals. I am a highly responsive person and can adapt according to client’s timezone and timelines Skills: • Strong knowledge of Android native app development and Android SDK • Strong knowledge of Android UI design principles, patterns, and best practices • Familiarity with the use of additional sensors( such as gyroscopes and accelerators) along with offline storage, threading, and performance tuning • Restful APIs creating through Java or Python (flask) and their consumption on mobile apps • Ability to understand business and technical requirements and transform them into actual application • Strong knowledge of Cloud vendors (AWS and Google) and Cloud technologies • Proficient understanding of code versioning and task management tools, like Git, Jira, Confluence, Sonar lint • Familiarity with continuous integration Specialties: 1. Java and Python 2. Apple and Google mobile device management 3. Android Development, Material and custom UI for all resolutions 4. Spring boot, JMS, Hibernate, Restful API 5. Tomcat and Jetty 6. Angular2+ and JavaScript 7. MySQL and MongoDB 8. Ec2, SES, SNS, RDS, S3,, DynamoDB, FireStore 9. Docker, Lambda, API Gateway 10. Flask 11. Linux, CentOS and Ubuntu 12. Application monitoring with Nagios and Grafana

Hi! Let’s have a free call to see if we’re a match. 𝗜 𝗯𝘂𝗶𝗹𝗱 𝗶𝗻𝘁𝘂𝗶𝘁𝗶𝘃𝗲 𝗺𝗼𝗯𝗶𝗹𝗲 𝗮𝗽𝗽𝘀 𝗮𝗻𝗱 𝗶𝗻𝘁𝗲𝗴𝗿𝗮𝘁𝗲 𝗰𝘂𝘁𝘁𝗶𝗻𝗴-𝗲𝗱𝗴𝗲 𝗔𝗜/𝗠𝗟 𝘀𝗼𝗹𝘂𝘁𝗶𝗼𝗻𝘀. 🚀 With 10+ years of experience in E-commerce, Tech, and Education, I bring a unique blend of software development, data science, and leadership expertise to every project. I love building impactful solutions and I am passionate about helping others in reaching their full potential. That has led me to work in a variety of roles over the last years: ⭐️ Data Scientist, delivering E2E projects ⭐️ Project Manager and Team Lead for cross-functional teams ⭐️ App and Website Development ⭐️ Interview Preparation for DataScience interviews (I’ve been plenty on both sides of the table) ⭐️ Career and Leadership coaching, also outside of Tech Fluent in German, Spanish, and English, I cater to clients worldwide. Whether you need expert coaching or a custom solution for your business, I’m here to help you succeed. Let’s connect and discuss how we can achieve your goals together! ---------------------- Please find below some more info, specifically about how my team operates in creating mobile applications. Find more details on our website jd55creations.com. 𝐖𝐡𝐚𝐭 𝐰𝐞 𝐨𝐟𝐟𝐞𝐫: ⭐️ End-to-End Mobile App Development: From concept over design to deployment, we build high-performance and secure mobile applications using Flutter for both iOS and Android platforms. ⭐️ AI Integration: We integrate AI models, such as GPTs, recommendation systems, or classification/regression models, to enhance your app with intelligent, data-driven features. ⭐️ Cloud Integration: We seamlessly integrate cloud services like Firebase for authentication, real-time databases, push notifications, and cloud functions, ensuring secure and scalable app infrastructure. ⭐️ API Integration: I have worked with many APIs such as ChatGTP, Vertex AI models, or different ticketing platforms (Eventim, Pretix). 𝐇𝐨𝐰 𝐰𝐞 𝐝𝐨 𝐢𝐭: ⭐️ Client-Centered Approach: We focus on thoroughly understanding your business needs, defining success criteria, and delivering custom solutions aligned with your goals. ⭐️ Iterative Design & Development: Our process includes project scoping, design creation, rapid iterations, and user feedback integration for continuous improvement. ⭐️ Maintenance & Scalability: Our apps are built for easy future updates and new features, ensuring seamless scalability and maintainability. 𝐌𝐲 𝐩𝐫𝐞𝐟𝐞𝐫𝐫𝐞𝐝 𝐭𝐞𝐜𝐡 𝐬𝐭𝐚𝐜𝐤 𝐢𝐧𝐜𝐥𝐮𝐝𝐞𝐬: ⭐️ Figma for Design ⭐️ Flutter for cross-platform development ⭐️ Firebase for scalable cloud solutions and authentication ⭐️ Vertex AI and Python (TensorFlow, pandas, scikit-learn etc) for preparing, training and deploying AI models ⭐️ BigQuery for large-scale data analysis and processing ⭐️ Docker and Google Kubernetes Engine for deploying containerized workflows and scalable pipelines. 𝐋𝐚𝐧𝐠𝐮𝐚𝐠𝐞𝐬 𝐒𝐩𝐨𝐤𝐞𝐧: ⭐️ German native | Deutsch als Muttersprache | Hochdeutsch ⭐️ Spanish bilingual / Español bilingual | He vivido y trabajado en Español desde hace 10 años ⭐️ English bilingual