Hire Top freelance JavaScript Developers in Maine

✅ 𝐅𝐮𝐥𝐥-𝐒𝐭𝐚𝐜𝐤 𝐃𝐞𝐯𝐞𝐥𝐨𝐩𝐞𝐫 | 𝐀𝐈 𝐀𝐩𝐩 | +𝟵 𝗬𝗲𝗮𝗿𝘀 𝗘𝘅𝗽𝗲𝗿𝗶𝗲𝗻𝗰𝗲 𝗶𝗻 𝗪𝗲𝗯 & 𝗠𝗼𝗯𝗶𝗹𝗲 𝗔𝗽𝗽 💻 Available +40 hours per week 🕓 On-time delivery 🏆 Verified Full-Stack Developer 🚀 Available to start right away! 👉 I have been working for +9 years on the largest IT companies as a web developer. Now I provide great quality on the Upwork for my clients. My goal is to do your business task and help you to earn money! Great communication is my big plus - I am always online when you needed me and I try to understand improve your project! 💬 What Clients said about me: "Working with Eric was a pleasure. He is extremely talented, professional and has an excellent network of developers that he works with to help your project A-Z. Project management, design and vision all in one package! Highly recommend for your project!" -- Eric, Mastery Holdings.co -- "Yehor is an amazing guy! Great programmer. Really detail oriented, was able to take direction and complete task with minimal oversight. Highly recommended!" -- Travis, FuelMarketing -- 🛠 My skillset are: - JavaScript (ES5, ES6), Typescript / Python - HTML5 / CSS3, Sass, Less - ReactJS, NextJS, GatsbyJS, Remix - VueJS, NuxtJS - Angular - Material UI, Semantic UI , Ant-Design, Tailwind, Bootstrap 3,4(Flex, Grid) - Headless CMS: Contentful, Prismic, Sanity.io, DecapCMS, NetlfyCMS, GraphCMS, FireCMS, StatamicCMS, GravCMS - Node.js, Express.js, Nest.js - Django, Flask, FastAPI - Dart, Flutter - v0.dev, Bolt.new, Lovable, Replit, Cursor - ChatGPT-5, OpenAI, ElevenLabs, Deepgram, Vapi - Object Oriented Programming (OOP) - Restful API, Restful API development - MySQL, MongoDB - Docker compose - Github, Gitlab, Bitbucket - React Native / Flutter - Supabase, Firebase - Amazon web services | EC2, Lambda, S3, Apprunner, etc and more. 📩 Send me a message or invitation, and let's build something amazing together. Best regards, Eric.

🟢 Available | 📅24/7 x 🌍Time zones 🟢 🧭 8+ Years of Experience 🧭 🧠 Senior Level of Software Industry 🧠 I’m Dennis, a Senior Front-End Engineer with 8+ years of exp delivering many high-performance, user-centric web, mobile, and PWA applications across real estate, AI, health, fintech, and more. Passionate about the fusion of technology, creativity, and AI, I specialize in AI-powered apps, automation, real-time systems, and immersive 3D/AR experiences—bringing a product-first mindset and startup agility to every project. Available 24/7, I’m your technical partner who thinks like a founder, ships with precision, and communicates like a teammate to help you build fast and confidently. 🎯 Key Areas of Expertise ✅ Frontend Engineering Build scalable web and mobile apps using React, Next.js (App Router), Node.js, Django, FastAPI, and Supabase with a focus on DX, modularity, and clean code in monorepos. ✅ Social Content Generation & Virality Create tools for short-form content (memes, clips, carousels) with GenAI and real-time APIs; automate publishing pipelines across TikTok, X (Twitter), Threads, and Instagram. ✅ Link-in-Bio & Deep Linking Develop branded link-in-bio tools with dynamic deep linking, mobile routing, UTM tracking, and QR flows to boost retention, engagement, and attribution. ✅ 2D/3D Visualization & Interactive UX Render high-performance visuals using Three.js, React Three Fiber, WebGL, Canvas API; experienced with point clouds, spatial data, and immersive analytics dashboards. ✅ Performance & Frontend Optimization Optimize Lighthouse scores, Core Web Vitals, and rendering using lazy-loading, code-splitting, hydration, and tuning React/Next.js apps for scale. ✅ Data Scraping & Normalization Build web scrapers with Playwright, Puppeteer, or headless browsers; structure unstructured data for dashboards, analytics, and AI pipelines. ✅️ AI Agents & Automation Design autonomous agents using LangChain, LlamaIndex, and OpenAI APIs for intelligent task routing, memory management, and workflow automation integrated into full-stack apps. ✅ Product-Led Engineering & Rapid Prototyping Own end-to-end delivery from idea and Figma to code; leverage Turborepo, tRPC, Prisma, Tailwind, and shadcn/ui for fast, iterative, business-focused shipping. ✅ DevOps, CI/CD & Tooling Implement CI/CD with GitHub Actions, Vercel, Docker, Railway; automate testing, previews, deployments, and environment config in modern monorepos and cloud platforms. ✅ Startup & Domain Expertise Led engineering initiatives in fintech, creator economy, music tech, and trading tools; excel in fast-paced, zero-to-one environments owning full delivery. 🏆 Featured Portfolios 🌟 Web based AR/VR Exibition App for Rental & Real Estate (WebGL & Three.js, Luma AI Genie) 🌟 Large-scale Data Anaylytic Platform (D3.js, Visx) 🌟 Booking and Transportation App (Google Map) 🌟 AI Voice Agent for Real Estate (powered by OpenAI & 11Labs) 🌟 Generative AI Social App (text and image generation using GPT-4 & Midjourney) 🌟 AI-Powered Nutrition & Wellness App 🌟 AI Video Editing and Enhancement Application (leveraging DeepMotion & Synthesia) 🌟 AI Chatbot for Customer Support 🛠️ Technologies and Platforms 🧩 Frameworks & Languages: React, Next.js, Node.js, Django, Flask, FastAPI, JavaScript, TypeScript, Python 🧩 Mobile Responsiveness: Tailwind CSS, ShadCN, DaisyUI, Material UI, styled components, SASS/SCSS 🧩 Performance: Zustand, Jotai, RTK, useS, SWR, GraphQL, tRPC, Prisma ORM 🧩 Authentication: OAuth, Better-Auth, Keycloak, Supabase Auth, Firebase Authentication 🧩 Data and Database: Supabase, PostgreSQL, MySQL, MongoDB, Firebase, Pinecone, SQLite 🧩 Cloud and Deployment: AWS (CloudFround, EBS, EC2, S3, Lambda), Firebase, GCP, Vercel, Heroku 🧩 Automation Platforms: Make.com, Zapier, n8n 🧩 AI and LLMs: OpenAI GPT-4/GPT-4o/DALL-E, Claude, Gemini, LangChain, Perona AI, Stable Diffusion, Midjourney, Whisper API, 11Labs, TTS/STT frameworks, ComfyUI (ControlNet, OpenPose), RAG, LoRA, Runway ML, Synthesia, DeepBrain AI, DeepMotion, Pictory AI 🧩 Audio and Voice Technologies: OpenAI Whisper, Google TTS/STT, 11Labs, Deepgram, Perona AI 🧩 Video Technologies: FFMpeg, OpenCV, GenAI 🧩 DevOps & Tools: AWS, GCP, Heroku, Vercel, Docker, Git, Jira, Trello, Asana, Postman, Swagger 🌐 Industries Served 🥇 Real Estate 🥇 Social Media 🥇 Video Content and Marketing 🥇 Healthcare 🥇 Fitness & Sports 🥇 SaaS 🥇 FinTech 🥇 E-commerce 🥇 Dating & Friendship 🥇 Travel & Hospitality 🥇 Education Whether you're launching an MVP, scaling a product, or integrating powerful AI features into your platform — I bring deep technical expertise, startup agility, and a product-first mindset to help you deliver real impact. Let’s turn your vision into reality — faster, smarter, and better. Feel free to reach out — I respond quickly and professionally. 💬 Ready when you are.

Professional with an overall experience of 8+ years in the industries like Real Estate, Web3, Healthcare etc. Extensively worked as Front-End developer and worked on Object Oriented JavaScript. Worked on multiple projects as Lead and has ability to build a website project from Scratch. Spearheaded successful transition from LAMP stack to MERN which cur latency by 40% and increased effectiveness of database administrators by 20%. Experienced with working on WebGL libraries used for Augmented Reality projects. Worked on Cloud technologies such as AWS. Proactive problem solver, team player and has excellent communication skills.

Highly skilled Web3 Developer with over 8 years of experience in building and deploying decentralized applications (DApps) on Ethereum and other blockchain platforms. Proven track record in smart contract development, security audits, and blockchain architecture design. Experienced in creating and optimizing cryptocurrency trading bots, including arbitrage, MEV (Miner Extractable Value), sniper, market maker, and copy trading strategies. Passionate about leveraging my technical skills to create innovative solutions that drive transparency and decentralization. Eager to contribute my expertise in blockchain technology and automated trading systems to a forward-thinking company.

There’s something satisfying about building a page that just feels right. That’s what I do—create Wix landing pages that are clean, effective, and user-friendly. My background started in graphic design, which means I bring an eye for layout and flow, not just drag-and-drop skills. Clients I’ve worked with often come to me frustrated—tired of DIY designs that look good on desktop but fall apart on mobile. I fix that. Every pixel matters. Every second of loading time matters. I ensure your visitors don’t bounce before they’ve had a chance to understand your offer. I’ve built landing pages for local businesses, digital agencies, authors, course creators, and even a few eCommerce shops testing new products. No templates. No fluff. Just thoughtful, strategic design made to reflect your brand and guide the visitor toward a single action. Let's build something better than average.

Landing pages are more than just pretty screens—they’re digital storefronts with a job to do: convert. Whether you're running paid ads, launching a new product, or testing a startup idea, I help businesses create landing pages that are fast, focused, and fully optimized for results. I specialize in developing clean, responsive, and mobile-first landing pages using modern tools like HTML5, TailwindCSS, Bootstrap, and lightweight JavaScript. I also build inside platforms like Webflow, Unbounce, or custom CMS setups, depending on your needs. What sets me apart? I don’t just develop; I think conversion. I study your target audience, integrate persuasive content structures, and implement A/B testing setups when needed. Need your page live in 24–48 hours? No problem. I work with urgency but never compromise on polish or performance. Whether it’s a single-page opt-in form or a complete funnel system, I build pages that work hard so you don’t have to. Let’s turn your visitors into action-takers.

Publishing an app to the Play Store involves a lot more than just uploading a file — it requires precision, compliance, and an understanding of how Google’s review process works. I’m Jenna, and while I’m still early in my career with just over a year of experience, I’ve already helped several clients successfully navigate the Android app publishing process, from final builds to policy checks and metadata preparation. My technical background includes working with Firebase, Node.js, JavaScript, and Tailwind CSS, alongside database tools like PostgreSQL and MySQL. I’ve also contributed to front-end apps using Angular and backends in Flask, giving me the flexibility to troubleshoot common publishing errors, manage release versions, and help developers meet Play Store guidelines with confidence. If you’re preparing to launch and need someone to make sure everything’s aligned for approval, I’m ready to help make it a smooth process.

Are you an entrepreneur or startup founder looking to turn your idea into a powerful SaaS product? I specialize in engineering scalable, cloud-based SaaS applications—from MVP to market-ready platforms. My goal is to help you validate your product fast and build a foundation that grows with your users. With hands-on experience in product strategy, backend architecture, and user-centric frontend design, I don’t just write code—I help shape the product. I work closely with founders, CTOs, and product teams to translate business goals into reliable and intuitive web apps. Here's how I can support your SaaS journey: ✅ MVP development using modern stacks (React, Next.js, Node.js, Firebase, PostgreSQL) ✅ Modular backend design for future scalability ✅ RESTful & GraphQL APIs for seamless integrations ✅ Secure user authentication (OAuth, JWT, Role-Based Access Control) ✅ Stripe, PayPal & other subscription billing systems ✅ Admin dashboards, analytics panels, and user management flows ✅ Full DevOps support: CI/CD, Docker, Cloud Deployment (AWS, Vercel, DigitalOcean) I’ve helped launch SaaS platforms in industries like EdTech, HealthTech, CRM, B2B services, and internal workflow automation tools. Whether you need a prototype to pitch investors or a robust solution for early adopters, I’ll help you build a reliable product that’s ready for scale. Let’s discuss your SaaS vision and bring it to life—fast, efficiently, and with long-term growth in mind.

Hi! I'm a backend developer who thrives on building scalable, reliable, and maintainable systems that power modern web and mobile applications. My passion lies in crafting solid architectural foundations and optimizing databases for speed and integrity, no matter how large the dataset or how complex the logic. Over the past few years, I've worked with startups and enterprises to design RESTful APIs, implement event-driven architecture, and fine-tune SQL and NoSQL databases such as PostgreSQL, MySQL, MongoDB, and Redis. Whether it's designing authentication systems, handling third-party integrations, or managing cloud functions, I focus on writing clean, efficient, and testable code. My go-to technologies include Node.js, Express, Django, and Python, and I’m experienced with deploying apps on AWS and DigitalOcean with CI/CD best practices in place. If you're building a product that demands a strong backend infrastructure—whether it’s an MVP or a growing platform—I'd love to bring my experience and problem-solving mindset to your team. Let’s make something stable, secure, and scalable together.

With years of experience as an SQL Developer, I specialize in crafting robust database solutions that support high-performance applications. From designing scalable schemas to writing complex queries and optimizing performance bottlenecks, I ensure that your data layer works seamlessly behind the scenes. I’ve worked with startups, agencies, and enterprises to structure data in ways that improve speed, accuracy, and long-term maintainability. I don’t just write queries — I build data infrastructures that scale. Whether you need a brand-new database schema, help migrating legacy systems, or optimization for slow queries, I bring a deep understanding of relational databases and best practices. ✅ Database schema design (normalization, indexing, relationships) ✅ Query optimization and performance tuning ✅ Stored procedures, triggers, views, and functions ✅ ETL pipelines and data migration scripts ✅ Experience with MySQL, PostgreSQL, SQL Server, and Oracle ✅ Database security and backup strategy ✅ Reporting, analytics, and data aggregation solutions Let’s ensure your data works for you — clean, fast, and reliable. I'm here to help with both short-term fixes and long-term database strategies.

As a seasoned Cloud Engineer with over 8 years of hands-on experience, I specialize in architecting, deploying, and managing cloud infrastructures across AWS, Google Cloud Platform (GCP), and Microsoft Azure. I help startups and enterprises alike achieve high availability, scalability, and security in their cloud environments. Whether you're migrating from on-prem to cloud, optimizing performance, or setting up secure CI/CD pipelines — I've done it all. ✅ Design and implement scalable cloud architectures using AWS, GCP, and Azure ✅ Automate infrastructure with Terraform, CloudFormation & Deployment Manager ✅ Set up secure VPCs, IAM policies, and role-based access control ✅ Configure high-availability load balancers, auto-scaling groups, and multi-region failovers ✅ Monitor and log cloud activity using CloudWatch, Stackdriver, and Azure Monitor ✅ Optimize storage, compute, and database usage to reduce monthly cloud costs ✅ Migrate legacy systems to the cloud with minimal downtime ✅ Configure Kubernetes clusters (EKS, AKS, GKE) and containerized deployments My approach is proactive and tailored — not just fixing problems, but preventing them. Let’s build a reliable, secure, and future-proof cloud infrastructure that drives your business forward.

As an experienced software developer with over 9 years of industry experience, I am well-versed in a wide range of programming languages, frameworks, and databases. I specialize in traditional software development as well as cutting-edge blockchain technology. My technical expertise includes front-end frameworks such as React.js, Next.js, Gatsby.js, and Vue.js, as well as server-side technologies like Node.js, Express, Nest.js, and Koa.js. I am proficient in statically typed languages like TypeScript, as well as dynamically typed languages like JavaScript, and am comfortable working with popular databases including MySQL, SQL Server, MongoDB, and PostgreSQL. With my strong understanding of blockchain and smart contract technology, I can help you develop decentralized applications and NFT marketplaces using Web3, Solana, Ethereum, and Truffle. I have experience in the planning, implementation, testing, and maintenance of these systems. My proficiency in cloud platforms like Azure, Firebase, and AWS allows me to ensure that your applications are scalable, secure, and available to users around the world. Additionally, I have experience with CI/CD tools like Jenkins, Git, and Docker, ensuring that your development process is efficient and streamlined.Throughout my career, I have worked on a variety of software development projects using different team structures and procedures. I have a proven track record of delivering quality work and building strong relationships with clients. My adaptability, problem-solving skills, and ability to work effectively in a range of environments make me an asset to any team looking to build or improve their software products. My technical expertise includes a wide range of programming languages, frameworks, and databases. I am proficient with the following tech stacks: • React.js, Next.js, Gatsby.js, Vue.js, Angular, TypeScript • Node.js, Express, Nest.js, Koa.js, Fastify • HTML, CSS, JavaScript, Bootstrap, jQuery • Python, Django, Flask • MySQL, SQL Server, MongoDB, PostgreSQL • C++, C#, .NET, NET Core, ASP.NET, GoLang • REST, GraphQL • Azure, Firebase, AWS, Jenkins, CI/CD, Git, Nginx, Docker, Kubernetes, Heroku, Netlify • Solidity, Web3.js, Solana, Ethereum, Smart Contracts, Truffle, Fantom, AVAX, Polkadot