I help businesses build SaaS platforms, web applications, mobile apps, and AI powered products that are scalable, user friendly, and ready for real world use. Over the past 10+ years, I have worked with startups, growing businesses, and established companies to launch MVPs, improve existing products, and build production ready applications. My experience spans mobile development, full stack web applications, SaaS platforms, AI integrations, and custom business systems. My core expertise includes: • Mobile App Development (Flutter, React Native, iOS, Android) • Full Stack Development (React, Next.js, Node.js, Laravel) • SaaS & Business Applications • API Integrations & Automation • AI Powered Features & OpenAI Integrations • WordPress, Shopify, and E-commerce Solutions I enjoy working on projects from idea to launch, but I'm equally comfortable joining existing products, fixing issues, improving performance, and helping teams scale their applications. My focus is always on writing clean, maintainable code, communicating clearly, and delivering solutions that support business goals rather than simply completing tasks. Whether you need a new product built, an existing application improved, or a technical partner to help move a project forward, I'd be happy to discuss how I can help.

Welcome to Dannenhauer Labs! Full Stack Developer | DevOps | Selenium Programming Languages: Java, Python, TypeScript, C#, PHP, GO, SQL Github Achievements: - Arctic Code Vault Contributor - Pair Extraordinaire - Pull Shark - Yolo Github Username: crypto-hippo Hi, I'm Dylan, a highly experienced Full Stack Developer with 6+ years of hands-on experience building scalable, maintainable web applications for clients across a wide range of industries. I specialize in crafting seamless user experiences on the frontend using React, Vue, Next.js, Nuxt.js and developing robust, secure backends with Java (Spring Boot), Python (Flask & FastAPI), and Node.js/Express. Currently diving into the Astro framework. I’ve helped businesses launch MVPs that generate revenue, revamp legacy systems, integrate third-party APIs, and build complex dashboards and SaaS platforms from the ground up. My work consistently emphasizes performance, clean code, and maintainability. Core Skills: Frontend: React, Vue, Next.js, Nuxt.js, TypeScript, Tailwind, Material UI, HTML5, SCSS Backend: Java (Spring Boot), Python (Flask, FastAPI), Node.js/Express, Astro, Next/Nuxt SSR DevOps: Docker, Kubernetes, Nginx, Apache, Linux System Admin Databases: PostgreSQL, MySQL, SQLServer, MongoDB, Firestore, Supabase, Firebase I'm Top Rated Plus on UpWork, with a track record of clear communication, on-time delivery, and client satisfaction. Whether you need a full-stack partner for a long-term project or a specialist to knock out specific features, I'm ready to help. My self-driven and self-taught approach to studying computer science is what made this dream possible. Web Scraping & Web Automation. In addition to full stack development, I have extensive experience in web scraping and web automation with Selenium. I’ve built dozens of high-performance tools for tasks like product monitoring, data extraction, and browser automation. One of my standout projects was a Windows application built in C#, Winforms, and Bunifu that launched parallel headless Chrome browsers to automate checkouts on Supreme New York, enabling users to secure limited-edition drops with speed and precision. My automation work spans a wide range of use cases, including crawling Amazon product listings, finding vehicles to flip on Craigslist, gathering market data on boats and funeral homes, as well as tracking competitor pricing in real time. Whether it’s navigating complex DOM structures, avoiding detection mechanisms, or designing tools for non-technical end users, my ability to automate the web efficiently and reliably is unmatched. Let’s build something great together! I am just getting warmed up so take advantage. Cheers, Dylan

Full-stack and React Native developer who builds web and cross-platform mobile apps, React, Next.js, Node.js, MongoDB · 5-star rated. Need one developer who can build your web app and mobile app without switching teams or losing context? I deliver complete, production-ready products across web and mobile — using React, Next.js, Node.js, MongoDB, and React Native for iOS & Android. Whether it's a SaaS web platform, a cross-platform mobile app, or both running off the same backend — I've got the full stack covered. What I build: ✅ Full-Stack Web Apps — React / Next.js + Node.js / Express backend ✅ Cross-Platform Mobile Apps — React Native (iOS & Android) ✅ REST API & GraphQL API — shared backend for web + mobile ✅ MongoDB & PostgreSQL Database Design ✅ Authentication — JWT, OAuth 2.0, NextAuth.js, Firebase Auth ✅ SaaS Dashboards, Admin Panels & Client Portals ✅ Push Notifications, Offline Support & App Store Deployment ✅ Responsive UI — Tailwind CSS, Material UI, Shadcn How I work: Clear communication, realistic timelines, and clean code your team can build on. You'll always know where the project stands — no surprises at delivery. Tech stack: JavaScript · TypeScript · React.js · Next.js · React Native · Node.js · Express.js · MongoDB · PostgreSQL · REST API · GraphQL · Firebase · Tailwind CSS · Expo · Git · Vercel · AWS Building a web platform, mobile app, or both? Send me your project brief and I'll respond promptly.

If the problem involves AI touching real decisions—and getting it right matters—I’m usually a good fit. I routinely deliver what would take most teams a week in a single day. As one former Upwork client put it: “Got a week’s worth of work done in less than an hour due to Jonathan’s expertise. Would work with him again, no question.” That speed comes from deep domain expertise and fluency with modern AI tooling, which I use as a force multiplier—not a shortcut. I move quickly because I know exactly what to build, what not to build, and how to avoid rework through systematic testing. Most of my work sits in environments where systems influence money, risk, or operations, and where errors are expensive. The goal is not experimentation or novelty. It is building systems that work the first time, explain their decisions, and remain reliable under scrutiny. I led the design and implementation of an AI-driven small-business credit platform for a publicly traded lender (~$40M+ annual revenue). The system automated the majority of application decisions by combining structured financial data, document understanding, and retrieval-augmented analysis with tool-enabled research. Within a controlled environment, the system could query internal data, perform constrained external searches, and assemble a 30-point underwriting profile aligned with senior credit-analyst reasoning. Crucially, the system enforced confidence thresholds and escalation logic. Only the most complex 10–15% of applications were routed to expert underwriters, allowing human effort to concentrate where judgment actually added value. Manual review fell sharply without increasing risk. Security was treated as a first-order constraint. All PII was isolated within private network boundaries, with encrypted storage and tightly scoped access. Even large-language-model interactions—including external research—were routed through secured infrastructure so sensitive data never left controlled environments. Most engagements begin with a short diagnostic phase. I’m direct about whether I’m needed at all—and when I’m not, I say so. Clients often use a less expensive developer for execution once the critical architectural and risk decisions are made. That discipline is part of the job. Selected Systems I’ve Built At Finally, a $100M Series-B payroll company, I designed and shipped a production payroll platform in roughly six weeks, making early architectural decisions that prevented later rewrites and operational debt. In academic publishing, I helped build and stabilize Refine.ink, an AI-driven peer-review platform used by faculty at leading U.S. universities, where rigor, explainability, and predictable behavior were non-negotiable. As Refine.ink’s co-founder put it: “Jonathan combines deep technical ability with unusually strong judgment. He consistently identified the right problems to solve and built systems we could trust in production.” — Ben Golub, Co-Founder, Refine.ink; former Professor of Economics and Computer Science at Harvard; current Professor of Economics at Northwestern University I’ve also built agentic and multimodal systems that execute real workflows: voice-driven legal intake systems that conduct structured interviews and route qualified matters directly into case management; and computer-vision pipelines where I fine-tuned custom object-detection models to classify industrial weld defects—often only a few pixels wide—achieving ~95% accuracy with a lightweight human-review loop. I’m typically brought in when teams need rapid progress without mistakes—when systems have to move fast and still hold up in production. I work quickly because I’m an expert at what I do and deeply fluent in AI tooling, which allows me to compress timelines without cutting corners.

Hello! I'm Stephen Carruthers and passionate about building websites and designing user interfaces to bring software to life. However, my true passion lies not only in solving problems, but providing the best possible solutions through cutting-edge technology. This mentality has enabled me to gain invaluable experiences skills, such as strategic thinking, effective communication, and comprehensive project development. I've played pivotal roles in designing, developing, and delivering exceptional desktop and web-based products. With extensive full stack experience, I specialize in technologies like PHP, JavaScript, TypeScript, WordPress, HubSpot, C#, and ASP.NET. I've extensive experience with concepts such as relational and document store databases, REST APIs, cloud engineering (AWS), CI/CD, and much more. If you're looking for a developer who merely closes tickets, there are plenty to choose from. However, if you want a top-tier problem solver and talented developer who can drive your projects to success, you have found the right person. Let's chat and see how I can help.

⭐ Full Stack Developer | .NET | PHP | MERN | AI | Mobile App Developer | Flutter Developer | iOS & Android Specialist I am a Full Stack Developer, Mobile App Developer, and Flutter Developer trusted by Google, Samsung, BMW, and LG. I help startups and enterprises build high-performance mobile apps and scalable web platforms using Flutter, .NET, PHP, MERN, Android, iOS, and AI technologies. If you're looking for a dependable Flutter App Developer, iOS Developer, Android Developer, Full Stack Developer, or MERN Developer, I can take your project from concept → UI/UX → development → backend → deployment → scaling. 🚀 Why Clients Hire Me Expert Full Stack Developer for web & mobile apps Senior Flutter Developer for cross-platform mobile apps Experienced iOS Developer & Android Developer for native apps Strong .NET Developer, PHP Developer, and MERN Developer AI-Driven App Development (chatbots, automation, ML features) Delivered 50+ successful apps for global brands Clear communication, fast delivery, and long-term support Clients frequently choose me when searching for: Full Stack Developer, Flutter Developer, Mobile App Developer, iOS Developer, Android Developer, .NET Developer, PHP Developer, MERN Developer, AI Developer. 💼 What I Do 📱 Mobile App Development Flutter App Development (iOS + Android in one codebase) iOS App Development (Swift, Xcode) Android App Development (Kotlin, Java) Firebase, REST API & cloud integrations UI/UX implementation, app optimization & bug fixing Full-cycle Mobile App Developer services from idea to rollout 🌐 Full Stack Web Development MERN Stack Development (MongoDB, Express, React, Node.js) .NET Web Development (ASP.NET, .NET Core) PHP / Laravel Development Custom REST API development Admin panels, dashboards, CRMs, web portals, SaaS platforms Backend architecture, authentication, cloud deployment 🤖 AI & Automation AI-powered mobile & web apps AI chatbot development Intelligent automation systems AI API integration (NLP, vision, recommendations, workflows) 🔧 Tech Stack Mobile Flutter, Dart Kotlin, Java Swift, Xcode Web / Backend MERN Stack (MongoDB, Express, React, Node.js) .NET, ASP.NET Core, C# PHP, Laravel JavaScript, jQuery Firebase, SQL, MySQL REST APIs, Cloud Integrations ⭐ Industry Expertise Taxi Web & App Developer Rideshare Web & App Developer Food Delivery Web & App Developer Grocery Delivery Web & App Developer E-commerce Web & App Developer Marketplace Web & App Developer On-Demand Services Web & App Developer Fitness Web & App Developer Health & Telemedicine Web & App Developer EdTech Web & App Developer Learning Management (LMS) Web & App Developer Job Portal Web & App Developer Social Media Web & App Developer FinTech Web & App Developer Digital Wallet Web & App Developer Crypto Wallet Web & App Developer Inventory Management Web & App Developer Real Estate Web & App Developer Vehicle Rental Web & App Developer Travel & Hotel Booking Web & App Developer Auction & Bidding Web & App Developer Subscription Web & App Developer SaaS Web & App Developer Productivity Web & App Developer Event Management Web & App Developer Dating Web & App Developer Parenting Web & App Developer Mental Health Web & App Developer Meditation & Mindfulness Web & App Developer Language Learning Web & App Developer News & Magazine Web & App Developer Podcast & Audio Streaming Web & App Developer 🎯 Ready to Build Your App or Platform? Click Invite to Job and let’s bring your idea to life — mobile, web, or AI.

I'm a health data engineer specializing in wearable and patient-generated data interoperability built on open standards. I'm a contributing member of the JupyterHealth software team (UC Berkeley / UCSF), where I serve as the primary developer and architect of the patient-generated data sync and Open Wearables integration work for the JupyterHealth Exchange. I build the tooling that gets data from devices like Oura, Whoop, Garmin, and Apple Health flowing into clinical-grade FHIR-based exchanges and in the standard Open mHealth format. My work covers: - Wearable data pipelines using Open Wearables and Open mHealth (IEEE 1752.1) - Patient-facing sync apps with consent, authorization, and reliable data delivery - FHIR interoperability for clinical and OMH for research systems - Health data infrastructure (Django, Fly(dot)io, AWS, CI/CD, OAuth2/OIDC, SAML) - SMART on FHIR integration (built an Epic integration through to production readiness) - AI-accelerated specification and development for health data systems I work in the open-source health ecosystem, not as a generalist learning on your dime. Clients keep ownership of standards-based, interoperable work with no proprietary lock-in.

🫡 Extremely Reliable, Communicative and Fast 🥇 The Top 1% of Talent (Expert Vetted) 💰 60+ apps shipped, generating over 8 figures in revenue. ⚡ AI speed combined with 8 years of production experience to deliver code that ships fast, feels premium, and scales without cracking. (Available for 2 projects in April 2026) 🛠️ Specializing in Mobile App Development | Flutter, Swift, or React | iOS and Android 🇺🇸 Honored as a Top Mobile App Developer for hire in the United States from 2020-2025. 🏆 Award Winning Mobile App Developer: previous app featured on Apple's List of Best Language Learning Apps. 📰 Featured on Business Insider for my innovative contributions to mobile app development on Upwork. I've had the privilege of propelling clients to significant milestones, including achieving $2M in Annual Recurring Revenue (ARR). Some notable successes include: - A restaurant subscription app reaching $100K+ Monthly Recurring Revenue (MRR) - A fitness community app achieving $1.5M+ ARR. ⭐️ Client Testimonials: "Michael is a gem in the world of mobile app development..." "Among the top 3 developers I've worked with over the past three years..." "A quality developer and a quality human being..." Upwork Stats: 🏅 Top 1% of Mobile Developers 🏅 Top 1% of iOS Developers 🏅 Top 5% of Firebase Developers 🏅 Top 5% of Swift Developers 🎓 Proud Michigan State University Graduate with a Bachelor's Degree in Computer Science. With a solid eight-year trajectory as a Mobile App Developer, I've honed my skills across a plethora of projects that span iOS and Android platforms, utilizing Flutter and Swift to create high-impact applications. My forte lies in converting ideas into digital realities that propel businesses forward. From crafting engaging user interfaces to optimizing backend processes, my holistic approach ensures a robust and scalable app solution. I thrive in various development scenarios, whether its working with a team to deliver a project on a tight deadline or building an application from scratch all on my own. My experience extends to working with startups that have secured significant venture capital funding, as well as established enterprises aiming to expand their digital footprint. 🌟 Why Choose Me: Client Satisfaction: My reviews reflect the genuine value I provide. Effective Communication: I prioritize prompt and sincere interactions to ensure project fluidity. Mastery: I strive for flawless, visually appealing apps worthy of portfolio inclusion. 😁 Excited to collaborate! Whether you're a startup aiming to elevate your product or an established enterprise looking to scale, I'm here to help. Let’s kickstart our partnership with a complimentary 30 minute discussion to blueprint your pathway to success. Specialities: Full Stack Development, AI Systems Architect, AI SaaS Developer, SaaS MVP Development, Mobile MVP Development, Cross-Platform Mobile Apps, Mobile App Development, iOS Development, Scalable SaaS Architecture, AI-Powered SaaS, Flutter App Development, React Native App Development, Backend Development, Frontend Development, Mobile App Architecture, Cross Platform App Development, AI Powered Applications, API Integration, API-Driven Mobile Apps, Cloud Architecture, Production-Ready MVP, Secure APIs, OpenAI Integration, AI Workflow Automation, LLM Integration

I professionally develop complex embedded and integrated solutions for remote control, access, connectivity, and monitoring. I have led and delivered multiple projects across automotive telematics, connected devices, retail systems, applied electronics, and backend/server platforms, including web-based applications and AI-enabled features such as video analytics, speech recognition, and intelligent automation. My background combines hands-on engineering with product leadership. I work across firmware, mobile apps, cloud services, hardware/software integration, and scalable backend systems. I am comfortable solving difficult real-world problems involving connectivity, reliability, performance, and deployment at scale. I have extensive experience managing multidisciplinary engineering teams, coordinating hardware and software development, and delivering products from concept through production. As a strategist and experienced technology leader, I can drive the full lifecycle of a project: architecture, execution, team leadership, launch, and continuous improvement. I bring a practical builder mindset focused on results, speed, quality, and turning ambitious ideas into working products.

☎️ Responsive | ⭐ Reliable & Quality Work | 🧠 Critical Problem Solving Airtable expert and AI Implementation architect. I combine technical skills with consultative problem-solving: asking the right questions, uncovering opportunities, and learning your business as if it were my own, to build better solutions. I design Airtable as the foundation, then layer on Make and n8n to connect your tools, and AI to do the actual work. Across the Claude stack — Claude, Claude Code, Cowork, Hermes, and OpenClaw — I build systems that go beyond chat: production scripts and custom interfaces, autonomous desktop agents, and always-on assistants that run workflows, monitor inboxes, and act across your apps 24/7. The result: operations that save time, reduce errors, and scale with your business. WHAT YOU CAN EXPECT WORKING WITH ME: • Quick, clear communication (I’m highly responsive) • A consultant’s mindset with a developer’s skillset • Systems built not just to “work,” but to truly improve how your business runs Looking forward to working with you! Joe