Hire the Best API Developers
in Spain
Barcelona, Spain
Need someone who can build, stabilize and scale your Android product? You just found him ๐ค ๐ 12+ years in mobile delivery ๐ 20+ Android-focused projects ๐ 10+ years supporting regulated and business-critical products ๐ Experience with compliance-ready apps, secure payments, backend-heavy systems and Software Development I help companies create secure, maintainable, high-performance apps for Healthcare, FinTech and consumer products. Core Expertise ๐น Native Android engineering with modern architecture and Software Design ๐น Kotlin-first development with maintainability in mind ๐น Legacy modernization from Java to Kotlin ๐น Secure integrations, performance tuning, release stability ๐น Product delivery for Healthcare, FinTech, consumer platforms and Mobile App Development Iโm an android developer focused on products where reliability and clean architecture matter. As a kotlin developer, I build scalable solutions with android kotlin best practices, Jetpack tooling and AOSP awareness. Clients come to me for android developer kotlin expertise when they need stability, lower technical debt and growth. I work as an android app developer on products that need more than interface implementation. I support teams with android app development for secure solutions where every android app stays maintainable after launch. My background: improving an android application used by thousands of users, integrating backend systems, payment flows, and healthcare-grade data handling. That is why companies hire me as an android mobile developer ( android mobile app developer ) when they need delivery. What I Do Best โ Android development using Kotlin and Java โ Architecture design with MVVM, Clean Architecture, modularization โ Backend communication, authentication and payment integrations โ Performance optimization, debugging, maintenance and release support โ Application Improvement for live mobile products โ Solo delivery or collaboration inside a larger team My strongest specialization is android developer kotlin work. I often join teams that need android developer kotlin java skills to modernize legacy code, migrate modules, and improve release quality without a full rewrite. That work benefits from practical experience as a java developer and from thinking like an android kotlin developer who can handle new features and stabilization. Relevant Experience Highlights ๐ธ Healthcare mobile applications with compliance-aware architecture ๐ธ Performance optimization and crash-rate reduction ๐ธ Secure data handling and app stability improvements ๐ธ Secure apps with payment integration and transaction-safe flows ๐ธ Backend integrations with PHP, Python, JavaScript, and REST APIs ๐ธ Collaboration with iOS, backend, QA, and web teams ๐ธ Ability to scale from one engineer to a delivery team I also have experience with android ble and android bluetooth features for pairing flows and reliable data exchange. Whether I contribute to an android mobile app or support an existing codebase as a mobile developer, I focus on release readiness. Tech Stack ๐ธ Android kotlin with Jetpack, Compose, Android SDK, AOSP ๐ธ Java, Firebase, secure cloud services, CI/CD ๐ธ REST APIs, secure auth, payment gateways ๐ธ Node.js, JavaScript, C#, SQL for backend alignment ๐ธ Git, Android Studio, release workflows, crash analysis ๐ธ MVVM, Clean Architecture, modular apps, scalability-first mindset My work is rooted in native Android, but I also understand broader product ecosystems. I collaborate effectively as an ios developer ( ios app developer ) when cross-platform alignment matters, including iOS Development discussions with teams using Swift. I have worked alongside teams using react native and reviewed delivery implications where flutter developer was involved, though I do not present those as my core specialization. That exposure helps me operate as an android developer and product-minded mobile app developer within cross-functional teams. Team & Product Collaboration ๐น Coordination with a rest api developer ๐น Alignment with web application development ๐น Communication with a web developer or front end developer ๐น Familiarity with database builder, django, and python automation Support I Can Provide โ๏ธ Build a mobile app from scratch โ๏ธ Join an existing product as an app developer android โ๏ธ Refactor legacy code and modernize architecture โ๏ธ fix android application bugs and improve release readiness I do not position myself as a wordpress, magento, game developer or unreal engine specialist and I do not use unrelated positioning such as android developer india. Even when someone types android develoer, they usually need a senior specialist who can take ownership. I built mobile applications for autism-related projects with intuitive user experience. ๐ฌ If you need an android developer who can improve an existing product, build a reliable solution from scratch or support growth with kotlin developer depth, send me a message.
- Android
- AOSP
- Kotlin
- Mobile App Development
- Flutter
- Node.js
- Android App Development
- Swift
- Firebase
- iOS Development
- PHP
- Java
- JavaScript
- React Native
- C#
- SQL
- Software Design
- Application Improvement
- Software Development
- Software Debugging
Barcelona, Spain
Hi, Iโm Dmitry โ a full stack and mobile engineer who builds and ships production ready web and mobile applications. Top Rated freelancer with 80+ projects and 3000+ hours of development experience. I help startups and companies build scalable backend systems, modern frontend apps, and Flutter mobile apps (iOS and Android), including App Store and Google Play releases. What I do: - Full stack web apps (Laravel, PHP, React, Angular, JavaScript) - Flutter mobile apps from MVP to production release - Scalable backend systems and REST APIs - Integrations, payments, SaaS tools - Fixing, refactoring, and improving existing systems AI assisted development: - I use AI tools as a development accelerator to speed up delivery, improve iteration cycles, and increase code quality, always combined with manual engineering, architecture design, and production level review How I work: - I focus on shipping working production systems, not just code - I take ownership and build stable, scalable solutions Best fit for: - Startups building MVPs - SaaS products needing backend and frontend development - Teams needing a reliable full stack + mobile engineer
- API Development
- RESTful API
- MySQL
- HTML
- CSS
- Laravel
- JavaScript
- PHP
- Angular
- Bootstrap
- React
- PostgreSQL
- AngularJS
- Git
- Web Application
Alicante, Spain
I am Aleksandra, leading a team of experienced full-stack developers specializing in AI-driven applications. We design and develop modern, scalable web and mobile solutions that integrate artificial intelligence, automation, and cloud technologies to optimize business operations. With over 20+ years of collective experience, we have worked with startups and enterprises across industries like FinTech, Healthcare, eCommerce, and SaaS. Our expertise spans the entire development cycle, from initial concept and UI/UX design to backend architecture, AI integration, SRE (Site Reliability Engineering), and cloud deployment. ๐ 194+ successful projects completed on Upwork with global clients ๐ฒ $5M+ earned on Upwork through high-impact full-stack and AI solutions โฑ 55,121+ hours billed, proving long-term client trust and engagement ๐ผ 600+ total projects delivered since 2000 across AI, web, and mobile ๐ 100% of developers hold engineering degrees, ensuring expert-level technical depth ๐ฉโ๐ป Advanced AI team includes Kaggle competition masters and top ML researchers ๐ 91%+ job success rate, reflecting top-tier performance and consistency ๐ 25+ AI-driven apps deployed in FinTech, EdTech, and HealthTech ๐ง 30+ machine learning models built and optimized for live environments ๐ 20+ industries served, from startups to Fortune 500 clients ๐งฑ Founded in 2000, bringing 24+ years of experience in software innovation ๐ 40+ React + Python full-stack solutions developed for scalable applications โก High-load systems deployed to serve thousands of concurrent users ๐ Client ROI increased by up to 70% in AI automation projects ๐ฌ Featured in Forbes, MBN Magazine, and Helsinki Times for client success stories Expertise: Full-stack development for web and mobile applications AI-powered solutions, including computer vision, natural language processing, and predictive analytics Scalable cloud architecture using AWS, Google Cloud, and Azure Real-time data processing and AI-driven automation Platform Engineering and Infrastructure as Code (IaC) GitOps workflows and CI/CD pipeline optimization API development and third-party service integrations Performance optimisation for high-traffic applications FinOps and cloud cost optimisation Secure and accessible web applications with SEO best practices Technology Stack: Frontend: React.js, Next.js, Vue.js, TypeScript Backend: Node.js, Python (FastAPI, Django, Flask), Golang AI & Machine Learning: TensorFlow, PyTorch, OpenAI API, Hugging Face, LLMOps Databases: PostgreSQL, MongoDB, Redis, Firebase Cloud & DevOps: AWS (Lambda, S3, DynamoDB, EC2), Docker, Kubernetes, Terraform, Helm, ArgoCD, GitHub Actions, GitLab CI/CD, Ansible, Prometheus, Grafana, ELK Stack Tools & Platforms: Figma for UI/UX, Miro for user flow mapping, Webflow for no-code development Why Work With Us? We focus on delivering intelligent, future-proof applications that drive business growth. Our team ensures seamless collaboration, clean code, and scalable architecture that adapts to evolving needs. We are committed to clear communication, efficient execution, and long-term support. If you are looking for a team that can build and scale AI-powered applications with a strong full-stack foundation, let's discuss your project. ๐ Keywords to find me: AI Developer | Full-Stack Developer | AI Applications | React Developer | Node.js Developer | Python Developer | AI Integration | SaaS Developer | Web App Developer | Mobile App Developer | Scalable Applications | AI-Powered Software | Computer Vision | NLP Engineer | Machine Learning Engineer | Backend Developer | Frontend Developer | Cloud Developer | Automation Engineer | Cloud Architect | GCP | AWS | Azure | TensorFlow | PyTorch | OpenAI | Hugging Face | FastAPI | Django Developer | Flask Developer | Golang Developer | MLOps | LLMOps | DevOps | SRE | Site Reliability Engineer | Platform Engineer | Kubernetes | Docker | Helm | ArgoCD | Terraform | Infrastructure as Code | IaC | GitOps | CI/CD | GitHub Actions | GitLab CI/CD | Jenkins | Ansible | Prometheus | Grafana | Datadog | ELK Stack | DevSecOps | FinOps | AIOps | Observability | Monitoring | Service Mesh | Istio | Crossplane | OpenTelemetry | HashiCorp Vault | Multi-Cloud | Serverless | Figma | Webflow | Miro | Firebase Developer | MongoDB Developer | PostgreSQL | Redis | REST API Developer | API Integration | Predictive Analytics | AI in FinTech | AI in Healthcare | AI in eCommerce | SaaS Application | Intelligent Automation | Real-Time Data Processing | Cross-Platform Developer | SEO-Friendly Development | Secure Web Applications | Scalable Web Architecture | UI/UX Focused Developer | AI SaaS Developer | AI-Powered Mobile Apps | Full-Cycle Development | AI Solutions for Business | Enterprise Software | Startup MVP Development | AI Team Lead | Cloud-Native Applications | Serverless Architecture | AI-Driven Optimization | AI Workflow Automation | Real-Time AI Solutions | AI-Enhanced UX | AI Web App | AI-Powered Dash
- Python
- Machine Learning
- Generative AI
- AI Agent Development
- Machine Learning Model
- Full-Stack Development
- Node.js
- React
- Computer Vision
- Mobile App Development
- MLOps
- DevOps
- Docker
- Kubernetes
- Amazon Web Services
- FastAPI
- TensorFlow
- Cloud Architecture
- Natural Language Processing
- Large Language Model
Barcelona, Spain
Hi, Iโm Pankaj ๐ A Shopify Expert with 10+ years of experience building high-converting E-commerce stores that drive traffic, sales, and long-term growth ๐ฐ I donโt just build storesโI create conversion-focused e-commerce systems designed to scale your business ๐ ๐ผ What I Can Do for You ๐ Shopify Store Design & Development Modern, clean & conversion-focused design Mobile-friendly & fast-loading stores โก Custom Shopify development & features Scalable store structure โ๏ธ Shopify Plus Development Advanced features & custom solutions High-performance UI/UX Built for scaling high-volume stores ๐ E-commerce Optimization (CRO) Improve conversions & sales Better user experience & navigation Checkout optimization A/B testing-ready pages ๐ Shopify SEO & Growth SEO-friendly product & category pages Keyword optimization for rankings Organic traffic growth strategies Technical SEO improvements ๐ฏ Landing Pages That Convert High-converting landing pages (PageFly, GemPages, Replo) Sales-focused layouts Built using proven buying psychology ๐ฆ Dropshipping & Store Setup Complete store setup Product research & winning products Supplier integration Optimized sales funnels ๐งฐ Tools & Platforms Shopify | Shopify Plus | WooCommerce | WordPress PageFly | GemPages | Replo | Klaviyo Google Analytics | SEO Tools ๐ Results You Can Expect โ High-converting Shopify store โ Better user experience & trust โ Increased traffic & sales ๐ฐ โ SEO-ready structure โ Scalable e-commerce system ๐ฌ Why Work With Me? โ 10+ years real experience โ Conversion-focused approach (not just design) โ Clear communication & regular updates โ Focus on results, not just tasks ๐ Letโs Build Something That Sells If you want a Shopify store that looks great AND converts, Iโm here to help ๐ ๐ฉ Send me a message and letโs grow your e-commerce business! ๐
- Ecommerce
- Shopify
- Shopify Templates
- Shopify Website Design
- Shopify Development
- Ecommerce Website
- Ecommerce Store Setup
- Shopify Website Redesign
- Shopify Plus
- Shopify SEO
- Ecommerce Site Setup
- Landing Page Design
- Web Design
- Ecommerce SEO
- Web Development
- Ecommerce Website Development
- Manage Ecommerce Site
- Ecommerce Product Upload
- Custom Ecommerce Store
- Ecommerce Theme Installation
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