Freelance Software Engineers in MadridFreelance Software Engineers in Madrid
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Esteban Aleart Salas's avatar
Esteban Aleart Salas
Madrid, Spain
Full Stack Dev & SaaS Architect, scalable B2B platforms.
New to Contra
Full Stack Dev & SaaS Architect, scalable B2B platforms.
Cover image for I designed and developed the
I designed and developed the La Carolina website, utilizing technologies such as Next.js and React. The website is responsive and features a modern and minimalist user interface. I implemented a gallery of images and a contact form for visitors to send messages to the company. Skills demonstrated * Development of web applications with Next.js and React * Design of modern and minimalist user interfaces * Implementation of image galleries and contact forms * Deployment of websites on Vercel -- Results * A modern and attractive website that clearly and concisely presents the company and its services. * A responsive website that adapts to different devices and screen sizes. * A contact form that allows visitors to send messages to the company in a easy and secure way.
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Cover image for Nakama (wearenkm.com (http://wearenkm.com)) es un
Nakama (wearenkm.com (http://wearenkm.com)) es un ecosistema de consultoría y desarrollo enfocado en la creación de productos digitales escalables. Trabajamos con startups y empresas en crecimiento para diseñar, construir y evolucionar plataformas web, SaaS y soluciones basadas en inteligencia artificial. Nuestro enfoque combina desarrollo full stack (JavaScript, React, Next.js), arquitectura de sistemas e integración de tecnologías modernas como APIs, automatización y modelos de IA (embeddings, RAG), permitiendo transformar ideas en productos sólidos y preparados para crecer. Más que desarrollo, en Nakama aportamos visión técnica y de producto, ayudando a tomar decisiones estratégicas que eviten deuda técnica y aseguren escalabilidad a largo plazo.
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Cover image for Parabola is a no-code automation
Parabola is a no-code automation platform that allows users to create custom workflows and automate tasks without requiring extensive coding knowledge. The platform provides a visual interface for designing workflows, integrating with various apps and services, and automating tasks. Key Features: * No-code workflow automation * Visual interface for designing workflows * Integration with various apps and services * Customizable workflows * Automation of repetitive tasks
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Cover image for * Personal Assistant: friendly and intelligent
* Personal Assistant: friendly and intelligent personal assistant, designed to provide helpful and informative responses. * Skills: can understand and respond to questions and has knowledge in a wide range of topics, from technology and programming to history and culture. * Conversation: can engage in real-time conversations, responding to questions and providing helpful information. * Information Search: can search for information from a variety of sources to provide accurate and up-to-date answers. * Learning: Tontin can learn and improve over time, thanks to user feedback and interaction. * Accessibility: is available 24/7, and can be accessed from any device with an internet connection. * Personalization: Tontin can adapt to the needs and preferences of each user, providing personalized and relevant responses.
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Software Engineer(1)
Simon Yagodin's avatar
Simon Yagodin
Spain
Mechanical Designer & Electronics Enthusiast 💡
Mechanical Designer & Electronics Enthusiast 💡
Cover image for Robot vending kiosk
Robot vending kiosk
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Cover image for Videogame prop weapon
Videogame prop weapon
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Cover image for Gas operated airsoft rifle for Novritsch
Gas operated airsoft rifle for Novritsch
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Software Engineer(1)
Gonzalo Franco's avatar
Gonzalo Franco
Spain
Software Engineer: Building Awesome Webs Apps & Products
Software Engineer: Building Awesome Webs Apps & Products
Cover image for Product Manager, Full-stack Engineer, CleanHero
Product Manager, Full-stack Engineer, CleanHero
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Cover image for Full-stack developer – OB Studio
Full-stack developer – OB Studio
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Cover image for CTO, Subletny.com
CTO, Subletny.com
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Cover image for CTO, OpenBroker.com
CTO, OpenBroker.com
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Software Engineer(4)
Carlos Cobo's avatar
Carlos Cobo
Madrid, Spain
Automation & Optimization Expert
Automation & Optimization Expert
Cover image for FinTech Digital Transformation
FinTech Digital Transformation
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Cover image for Batch Processing Solution (PBs/day)
Batch Processing Solution (PBs/day)
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Cover image for Revamp CI/CD pipeline for a Fintech
Revamp CI/CD pipeline for a Fintech
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Software Engineer(3)
Luke Jovanovic's avatar
Luke Jovanovic
Madrid, Spain
agencra.xyz - Automated Pipelines. Ship in days, not weeks.
$5k+
Earned
27x
Hired
5.0
Rating
5
Followers
REPLIT_EXPERT

Expert

agencra.xyz - Automated Pipelines. Ship in days, not weeks.
Cover image for Yield-Nexus — Real-Time Crypto Portfolio
Yield-Nexus — Real-Time Crypto Portfolio & Trading Platform We built Yield-Nexus as a real-time crypto portfolio and trading dashboard aggregating data across Binance and Bybit. Traders needed a unified view of spot holdings, futures positions, and PnL without switching between exchange consoles.
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Cover image for Concordium — Supply Chain &
Concordium — Supply Chain & Testnet Infrastructure We delivered two blockchain projects for Concordium: a supply chain track-and-trace system and a testnet faucet. Track-and-trace: - Built a CIS-3 NFT smart contract (Rust) for product tracking. - Added sponsored transactions so users don’t need to hold tokens. - Implemented an indexer to track all on-chain movements in real time. - Shipped a full frontend and Docker-based infrastructure. Testnet faucet: - Developed a Next.js faucet with Cloudflare Turnstile bot protection. - Added per-address daily limits and balance checks via the explorer API. - Provided complete documentation for deployment and maintenance. Outcome: - Both systems production-ready and actively used. - 92 combined commits, clean architecture, ready-to-reuse patterns. This case shows our ability to ship end-to-end blockchain solutions—smart contracts, infrastructure, and UX—in one go.
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Cover image for NYC Watch Party Finder — From Idea to Production in 3 Days
NYC Watch Party Finder — From Idea to Production in 3 Days
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Cover image for Alephyr — Trading Engine with Evolutionary Optimization
Alephyr — Trading Engine with Evolutionary Optimization
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Software Engineer(1)
Sergio Gutierrez's avatar
Sergio Gutierrez
Madrid, Spain
Full Stack Engineer. Building mobile app prototypes.
6
Followers
Full Stack Engineer. Building mobile app prototypes.
Cover image for A glimpse into my most recently published app for an investm...
A glimpse into my most recently published app for an investment client I had the luck to work with
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Cover image for Today's exploration is a redesign of one of my first publish...
Today's exploration is a redesign of one of my first published apps: Trufario, your doggo's personal tracker. Do you have a favorite?
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Cover image for Some old work of mine: Trufario, an app tracking your dog's ...
Some old work of mine: Trufario, an app tracking your dog's most important events throughout the day to find triggers for your companion's problems. One of the first apps I created from its conception to the stores and still proud of it.
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Cover image for Considering what my next prototype would be. This is today's...
Considering what my next prototype would be. This is today's quick design session exploring the idea of a self-hosted location tracker (bye bye Google Maps Timeline). Wondering if anyone here would like to use it.
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Software Engineer(1)
JR Alonso's avatar
JR Alonso
Madrid, Spain
Web and Blockchain developer
Web and Blockchain developer
Cover image for Twitter clone
Twitter clone
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Cover image for Release Club
Release Club
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Cover image for ERC20 Token Generator
ERC20 Token Generator
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Software Engineer(3)