Hire the best API Developers in Barcelona, ES

Check out API Developers in Barcelona, ES with the skills you need for your next job.
  • $50 hourly
    I'm a senior full-stack developer (C# / Angular) with 15+ years of experience. I'm a hard worker and always stick to strict deadlines and business goals of my customers. I'm open and encourage direct and honest communication with my clients. What I enjoy the most is working on complex projects that have challenging tasks, I'm always willing to learn and try new technologies. During my career, I have worked on projects for large enterprises (Dell and Deutche Bank) as well as small startups; I've learned to be both methodological and pedantic when it comes to writing the robust code, and flexible when it comes to rapidly changing requirements and environment. I have advanced knowledge in the following technologies. - .NET (c#, asp.net core, Entity Framework, asp.net MVC WebAPI) - Multithreading, async programming - Great frontend skills - Angular 2+, React - Database development (MS SQL, PostgreSQL), PL-SQL / stored procedures - Messaging : SignalR, Rabbit MQ, Kafka - BI/Reporting (SSRS, Power BI) I look forward to learning more about your project, let's touch base and start discussing your requirements.
    vsuc_fltilesrefresh_TrophyIcon API Development
    .NET Core
    Angular
    Machine Learning
    React
    Microsoft Azure
    Microsoft Power BI
    ASP.NET Web API
    API Integration
    ASP.NET MVC
    Azure DevOps
    TypeScript
    SQL
    C#
    Entity Framework
  • $100 hourly
    I'm a Software Engineering Lead and Architect with over 15 years of experience in the software industry. I specialize in leading and organizing software development processes for diverse projects, including CRM Systems, Integrated Business Solutions, Web Services, E-Commerce Websites, Embedded Applications, and Social Networks. My key strengths include: - Translating business requirements into technical solutions - Building and managing effective development teams - Guiding projects from start to successful completion - Solving complex technical and organizational problems I have a broad technical background, specializing in web development (JavaScript, TypeScript with modern frameworks, PHP) and server-side applications (Golang). My expertise extends to building microservices with various cloud services and queues. Additionally, my DevOps skills include constructing private networks, implementing security practices, dockerizing applications, and establishing seamless CI/CD workflows. In team management, I organize team development flow, write technical documentation, and define coding standards. My leadership and analytical skills ensure that projects meet and exceed client expectations. Please feel free to reach out with any questions or project inquiries!
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    MySQL Programming
    PostgreSQL Programming
    Yii2
    JavaScript
    Node.js
    React
    PHP
    SaaS
    MongoDB
  • $80 hourly
    I have 25+ years experience in programming, 20 years with Javascript and 10 years with the MERN stack and mobile native development too. I grew up in Paris, for my degree, I moved to San Francisco in the mid 90s and started learning web oriented progamming language such as PHP / Javascript but also VRML. I developed mainy basic website or brochure for local companies in California then I moved on to more sophisticated digital services in the early 2000s and then starting 2008 I added mobile programming to my expertise. I ended up knowing the full spectrum of modern digital production, ranging from mastering multiple programming languages on different plateforms or devices, server administration, API development and network managment. In my career, I’ve programmed as an employee, as a freelancer but also as a founder of multiple companies in France, USA or China. I’ve developed many projects by myself or worked as a progamming team leader within teams of chinese or french developers. Over all these years, I’ve also developed my own personal projects. Ranging from an online visual CMS, an online publishing service, an online file management service. I’m tayloring since 2019 Brainers, a React native Dapp linked to an ethereum smart contract. I also R&D the blockchain technology, the AR technology, due to the coming boom of the smart glasses, and also the AI technology with Tesseract and Tensorflow. I’m always eager to learn more competences. Regarding functionalities, I’ve done many MERN projects, APIs, User management, signin, regristration, account profile, emailing scripts. I’ve done data handling as well, metrics and optimization. Navigation and User experience too. I’ve worked with 2D or 3D assets, using Webgl and libraries like threejs, imagemagick or FOP for example. I also do lots of file processing, conversion, automatization and syncronization between servers or online services such as AWS. In the last years I’ve focused on NFT and blockchain technology with ERC720/1135 tokens.
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    ExpressJS
    RESTful API
    Cucumber
    Database
    API
    Back-End Development
    Vue.js
    Front-End Development
    Python
    Amazon Web Services
    MongoDB
    React
    MySQL
    Node.js
  • $65 hourly
    Upwork achievements: 100% Job Success 🌟 Top Rated Plus 🚀 Web developer with over a decade of expertise in creating web applications and APIs. Proven track record of delivering high-quality solutions in both small startup and large enterprise environments. Technologies I use in frontend: Angular, Ionic, Nx, NgRx, RxJS, Three.js, D3, Playwright, Jest, TypeScript, Angular Material, Bootstrap, SAP Spartacus... I can architect and implement web apps of varying complexities, ensuring high performance and maintainability. Can upgrade your app to the latest version of Angular, incorporating new features and optimizations. I can create a "zoneless" Angular app, for the best performance possible, close to vanilla JS. I know all the latest features of Angular (Signals, Standalone Components, lazy loading...) and can consult your team. Extensive experience in building robust systems including WMS, CRM, and ERP applications, with a focus on scalability and user experience. Proficient in creating data visualizations using Canvas API, WASM, Three.js, Service Worker API, and many others, ranging from simple charts and animated UI parts to advanced 3D modeling applications. Using Rust, I can implement APIs following the Service-Oriented Architecture (SOA) and the OpenAPI Specification. I prioritize writing code in Rust that is both safe and fast, leveraging the language's strengths in these areas. My expertise in Rust primarily lies in web development, encompassing REST APIs, database connections, data analysis, and background task execution. I have extensive experience in caching, including handling mutexes, semaphores, preventing dog-piling and race condition effects, and ensuring Resource Acquisition Is Initialization (RAII) for optimal resource management. One of my notable accomplishments is developing a 100% Rust REST API that serves multiple web and mobile applications, including CRM systems, task managers, mobile apps, and websites. As a contractor, I've been working with Vodafone (devices control system, reports generator), NTT & Sony (custom payment module for Spartacus CRM). Advocate for declarative coding practices, ensuring comprehensive test coverage and flexibility for future enhancements. My favorite books are "Clean Code", and "Patterns of Enterprise Application Architecture". I like and respect SOLID principles.
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    Material Design
    RxJS
    Software Consultation
    Front-End Development
    Rust
    RESTful API
    Code Review
    Figma
    Redis
    TypeScript
    Angular
    MySQL
    Ionic Framework
  • $40 hourly
    I am a hardware/ software developer with experience working with microcontrollers and hardware architectures for machine learning workloads. Moreover, I have experience developing electronics circuits from the design , pcb and layout to the firmware implementation and testing. Also, my background includes developing web apps using NodeJS and VueJs.
    vsuc_fltilesrefresh_TrophyIcon API Development
    C
    Vue.js
    Firmware Programming
    Computer Engineering
    ARM Cortex-M
    Digital Electronics
    Microcontroller
    Machine Learning
    Algorithms
    Node.js
    C++
  • $40 hourly
    My professional career spans 20 years of diverse experience in software development, covering a broad spectrum of technologies and platforms. I’ve developed websites, web applications, mobile apps, APIs, and desktop applications, delivering solutions that are both robust and user-centric. In recent years, I have focused on modern frameworks and technologies, including Flutter for cross-platform mobile development, Swift for native iOS apps, and React for dynamic and responsive front-end experiences. My backend expertise includes C#, Node.js, Python and databases with mostly PostgreSQL and mongodb. I pride myself on my ability to adapt to new challenges, solve complex problems, and deliver high-quality results. My work is driven by a commitment to precision, thoroughness, and user satisfaction. Whether it’s creating scalable APIs, crafting intuitive user interfaces, or optimizing performance, I bring a comprehensive and detail-oriented approach to every project. I am available for consulting, software development, testing/debugging, and other services, ranging from short-term engagements to long-term collaborations.
    vsuc_fltilesrefresh_TrophyIcon API Development
    FastAPI
    Python
    Angular
    Web Development
    REST API
    Mobile App
    Oracle
    PostgreSQL
    Database
    Swift
    Flutter
    React
    .NET Framework
    C#
  • $50 hourly
    13+ years of experience in the software engineering field. Strong leadership skills. Experience in building highly effective teams from scratch. Passionate engineer with a strong background in DevOps and Quality Assurance fields. Go, Python, Java programming skills. Strong knowledge of microservice architecture patterns and best practices. Experience in building large-scale high availability distributed systems. Strong understanding of DevOps processes. Hands-on experience with AWS, Google Cloud Platform, Digitalocean. Experience with Docker and modern container orchestration platforms like Kubernetes, Nomad, Swarm. Experience in building CI/CD processes from scratch. Experience in providing real-time monitoring, observability, distributed tracing, alerting, and incident management. Experience in the migration of huge monolithic applications to microservices. Huge experience in Automation testing.
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    Google Cloud Platform
    DigitalOcean
    Docker
    Continuous Integration
    Terraform
    DevOps
    Amazon Web Services
    Golang
  • $70 hourly
    I am a Software Engineer with 15 years of experience in analysis, design, development, and quality software. My expertise includes object oriented programming, design patterns, software engineering, agile methodologies, and software life cycle. I have worked as a developer, SDET, QA Automation, and technical lead.
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    NUnit
    Unit Testing
    TestNG
    Software Design Pattern
    Selenium WebDriver
    Java
    C#
    Jenkins
    API Testing
    Docker
    Integration Testing
  • $20 hourly
    Enthusiastic and Passionate Freelancer on UpWork, Specializing in Python Development, Web Automation, BOTS, Web Scraping, and Data Analysis. Extensive experience in Python. Firm grip in Data Extraction, Transformation and Loading(ETL) from different numerous data sources. Sound knowledge of Software Development, Web Automation, Data Analysis, AWS EC2, and BOTS. Projects I have done Recently in Python: 1) UK VISA Appointment Update System, in which the BOT keeps checking the website 24/7 running on AWS EC2 and update the client using TELEGRAM whenever there are appointments available. 2) Portugal ID and Passport Update System, same as the UK Appointment, it updates the client using TELEGRAM and also running 24/7 on AWS EC2. 3) Python Conference Scheduler, It schedules any meetings/conference which of 3 or 4 days. You have to provide timing, name of speaker and name of conference else the program will do. 4) Different Python Security Algorithms 5) Python Data Scraping from different websites, including some of the top e-commerce websites. I am eager to work with you to provide reliable, consistent, High-level solutions to development problems. Feel free to contact me to discuss the workflow of your business needs.
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    Machine Learning
    HTML
    Data Analysis
    Data Science
    Subtitles
    Deep Learning
    Data Visualization
    Python Script
    Flask
    Automation
    JavaScript
    Web Crawling
    Python
    Beautiful Soup
    Data Scraping
    Selenium
  • $12 hourly
    PROFILE & CAREER OBJECTIVE Irish and British citizenship. Eligible to work in EU and UK without Visa. A creative and detail-oriented developer with 3+ years' experience in .NET development. Microsoft Certified Solutions Associate. Confident in writing code to create user-friendly, high quality systems. Flexible, open-minded person with proven ability to adapt to new situations and learn new skills. Comfortable working as a team, collaborating towards completing client requirements and communicating progress. Currently searching for a software development role alongside an experienced team that will provide valuable knowledge and experience for a successful career within software development. Extremely interested in exploring options outside of Ireland.
    vsuc_fltilesrefresh_TrophyIcon API Development
    Algorithm Development
    Data Processing
    CSV
    XML
    JSON
    Problem Solving
    Web Development
    .NET Core
    Python
    .NET Framework
    C#
  • $10 hourly
    I'm an experienced developer with almost 4 years of expertise in building web applications, whether it's backend, frontend, or both. My toolkit includes Python, JavaScript, Django, Node.js, React, AWS, and Terraform. Additionally, I leverage no-code tools to develop fully functional websites with backend and database capabilities, enabling me to deliver projects 3x faster than traditional methods. Tools: WeWeb, Webflow, Wix, Xano, Supabase... This fusion of no-code expertise with my engineering background ensures the creation of scalable and efficient solutions in a record time. Furthermore, I collaborate with an experienced designer on my team who can create designs from scratch.
    vsuc_fltilesrefresh_TrophyIcon API Development
    Supabase
    Wix
    Webflow
    WeWeb
    NodeJS Framework
    Software Development
    MongoDB
    PostgreSQL
    React
    JavaScript
    Django
    Python
    Web Application
  • $28 hourly
    A Senior Software Developer with over 10 years of enterprise software development. I am currently the CTO of Level5 Digital and previously the head of Application and Database at ACTV (African Cable Television). Outside of work, i am actively involved in a number of disruptive technology projects. One of these is Koborent; a real estate application that aims to change the way people search for properties online. The second is Pharma Business Insight; a data and analytics platform for pharmaceutical companies and the Federal Ministry of Health (Nigeria). My technical capabilities includes PHP (Laravel), Python (Flask & Django) , JavaScript (VueJS, React), Golang MySQL and some great DevOps skills.
    vsuc_fltilesrefresh_TrophyIcon API Development
    Laravel
    AWS Systems Manager
    Vue.js
    CSS 3
    MySQL
    HTML5
    JavaScript
    PHP
    Golang
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