Hire the Best API Developers
in Spain

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Alejandro V.

A Coruna, Spain

$30/hr
4.9
6 jobs

I am a technical architect with more than 20 years of experience in the field of construction. I am specialized in programming on Tekla Open API. I offer my experience in the development of jobs in Tekla Structures. Let me know your needs and see if we can establish a framework for collaboration

  • C#
  • Tekla Structures
Vadim P.

Barcelona, Spain

$40/hr
5.0
22 jobs

Need someone who can build, stabilize and scale your Android product? You found him 🤝 📊 12+ years in mobile delivery 📊 20+ Android-focused projects 📊 10+ years with regulated and business-critical products 📊 30+ production Android release cycles 📊 5+ years in Kotlin-first development 📊 4 product areas: compliance-ready apps, secure payments, backend-heavy systems and Software Development I help companies build secure, maintainable apps Healthcare, FinTech, consumer products. Core Expertise 🔹 Native Android engineering with modern architecture and Software Design 🔹 Kotlin-first development for maintainability 🔹 Legacy modernization Java to Kotlin 🔹 Secure integrations, performance tuning, release stability 🔹 Product delivery for Healthcare, FinTech, consumer platforms and Mobile App Development I’m an android developer focused on reliability and clean architecture. 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 as ai mobile app developer ✅ Android development using Kotlin and Java ✅ Architecture design with MVVM, Clean Architecture, modularization ✅ Backend communication, authentication and payment integrations ✅ Performance optimization, debugging, maintenance and release support ✅ Application Improvement for live mobile products My strongest specialization is android developer kotlin work. I join teams that need android developer kotlin java skills to modernize legacy code, migrate modules, and improve release quality without a full rewrite. That benefits from practical experience as a java developer from thinking like an android kotlin developer who can handle new features and stabilization. Relevant Experience Highlights as a full stack mobile app developer 🔸 Healthcare mobile applications with compliance-aware architecture 🔸 Secure data handling and app stability improvements 🔸 Secure apps with payment integration and transaction-safe flows 🔸 Backend integrations with PHP, Python, JavaScript, and REST APIs 🔸 Collaboration with iOS, backend, QA, full stack developer 🔸 Ability to scale from one engineer to a delivery team I also have experience with android ble, android bluetooth features for pairing flows, 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, ai mobile app development. Tech Stack 🔸 Android kotlin with Jetpack, Compose, Android SDK, AOSP 🔸 Java, Firebase, secure cloud services, CI/CD 🔸 REST APIs, secure auth, payment gateways, mobile app development api 🔸 Node.js, JavaScript, C#, SQL backend alignment 🔸 Git, Android Studio, release workflows, crash analysis 🔸 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 🔹 Coordination with a rest api developer 🔹 Alignment with web application development 🔹 Communication with a web developer or front end developer 🔹 Familiarity with database builder, django, and python automation Support I Can Provide ✔️ Build a mobile app from scratch ✔️ Join an existing product as an app developer android ✔️ Refactor legacy code modernize architecture ✔️ 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. 📬 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.

  • AOSP
  • Kotlin
  • Mobile App Development
  • Flutter
  • Node.js
  • Android App Development
  • Swift
  • Firebase
  • iOS Development
  • JavaScript
  • Software Design
  • Python
  • ExpressJS
  • SQLite
  • Android SDK
  • iOS SDK
  • Google Play
  • App Store
  • REST API
  • Software Debugging
Aleksandra L.

Alicante, Spain

$47/hr
4.9
169 jobs

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. 🏆 194+ successful projects completed on Upwork with global clients 💲 $5M+ earned on Upwork through high-impact full-stack and AI solutions ⏱ 55,121+ hours billed, proving long-term client trust and engagement 💼 600+ total projects delivered since 2000 across AI, web, and mobile 📚 100% of developers hold engineering degrees, ensuring expert-level technical depth 👩‍💻 Advanced AI team includes Kaggle competition masters and top ML researchers 📊 91%+ job success rate, reflecting top-tier performance and consistency 🚀 25+ AI-driven apps deployed in FinTech, EdTech, and HealthTech 🧠 30+ machine learning models built and optimized for live environments 🌎 20+ industries served, from startups to Fortune 500 clients 🧱 Founded in 2000, bringing 24+ years of experience in software innovation 🛠 40+ React + Python full-stack solutions developed for scalable applications ⚡ High-load systems deployed to serve thousands of concurrent users 📈 Client ROI increased by up to 70% in AI automation projects 💬 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. 🔑 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
Dmitry T.

Barcelona, Spain

$70/hr
4.6
103 jobs

Hi, I’m Dmitry — 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

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