Germán Castro Montes

Fullstack Developer

Granada, Spain germancastromontes@gmail.com

Senior Full-Stack Developer with 7+ years building scalable web applications and AI-powered platforms. Technical leader experienced in mentoring teams, system architecture, and delivering complex projects from MVP to enterprise-scale.

Experience

  • FullStack Developer / Technical Leader

    EZRA Climate (StriveLabs)
    February 2025 to Present

    ClimateTech startup accelerating climate solutions financing through AI-powered due diligence tools

    • Technical leadership: Led team of 4 developers + QA, defining complete system architecture and coordinating directly with VP of Product to establish technical roadmap
    • AI-powered platform: Built end-to-end due diligence platform processing 5,000+ financial documents across 100+ deals using multi-LLM integration with optimized prompt engineering
    • Rapid delivery: Delivered fully functional system in under 6 months using Next.js, FastAPI, and Supabase with continuous scaling capabilities
    Next.jsFastAPISupabaseOpenAIGeminiClaudeVercel AI SDK

  • Mobile Developer

    DigitalWisdom AI (StriveLabs)
    January - February 2025

    White-label AI coaching platform enabling rapid deployment of personalized coaching avatar apps

    • Multi-tenant architecture: Co-developed white-label mobile platform enabling rapid deployment of customized AI coaching apps for multiple clients with dynamic branding and content configurations
    • AI coaching integration: Implemented comprehensive AI experience with Gemini LLM supporting text/voice interactions and streaming responses using Vercel AI SDK
    • Rapid deployment: Delivered functional MVP within 2-month timeline enabling 3 sub-client deployments
    React Native (Expo)FirebaseGemini AIVercel AI SDKTanStack Query

  • Mobile Developer / Consulting Specialist

    Achaemenid (StriveLabs)
    November - December 2024

    Mobile app enabling wireless intraoral biosensor data capture for sleep apnea monitoring

    • Critical problem resolution: Contracted to resolve production-blocking BLE connectivity issues preventing medical client delivery. Successfully diagnosed and fixed persistent device disconnections within 2-week timeline
    • Medical device integration: Implemented robust BLE connectivity with intraoral biosensors (oxygen saturation, heart rate, motion) and enhanced UI/UX for medical professionals
    React Native (Expo)Bluetooth Low Energy (BLE)Sentry

  • Backend Cloud Developer

    SPAN
    June 2022 - November 2024

    Backend developer for production energy management platform serving hundreds of smart electrical panels

    • API development & optimization: Developed GraphQL APIs with multi-layer caching systems, reducing response times from several seconds to under 1 second. Implemented database optimizations and performance improvements across the platform
    • Energy sector integrations: Built integrations with major battery systems (Tesla Powerwall, Enphase, FranklinWH) and energy utilities using AWS Lambda and webhook architectures
    • System architecture & leadership: Led performance optimization initiatives and system-wide improvements while managing 3-person development team. Progressed from mid-level to senior developer on enterprise production systems
    GraphQLApollo ServerTypeScriptNode.jsPythonAWS LambdaPostgreSQLRedisDocker

  • Unit Lead & Technical Mentor

    Celtiberian
    February 2022 - September 2024

    Technical leadership role focused on training junior developers and leading internal innovation projects

    • Training & mentorship: Designed training program for ~20 junior developers achieving 90% success rate transitioning to client-ready professionals within 3 months. Established code standards and conducted technical interviews
    • Innovation project leadership: Led development of web scraping platform (Puppeteer/Playwright) and AI-powered HR tool with OpenAI integration for talent acquisition, managing cross-functional teams of 2-3 developers per project
    ReactNext.jsTypeScriptPythonPuppeteerPlaywrightOpenAI API

  • Backend Developer

    Rhythm360
    July 2020 - June 2022

    Cloud-based cardiac device management platform with HIPAA compliance

    • Healthcare integrations: Developed Django backend integrating with cardiac device manufacturers (Abbott, Biotronik, Medtronic) using reverse engineering and web scraping
    • Data processing: Implemented Celery task scheduling for automated patient data collection
    DjangoPythonVue.jsCeleryPuppeteerPostgreSQL

  • Fullstack Developer

    Other Positions
    2019-2020

    Full-Stack Developer - Corverix: HIPAA-compliant cardiovascular health platform with wearable device integrations
    Backend Developer - SMBX: Small business bond marketplace with peer-to-peer lending platform
    Frontend Developer - Seventh.ai: AI-powered intellectual property analytics platform

Projects

  • Oreinos Home

    Custom 3D topographical trophy display e-commerce platform

    Next.jsShopify APISTL GenerationGeospatial APIsCloudflare R2
    View details Project Link

  • AI Storyteller

    Open-source web app for creating interactive stories powered by AI.

    Tanstack StartReactAI SDK (Google Gemini)Tailwind CSSBrutalist UITypeScript
    View details Project Link GitHub Repo

  • URL Summarizer

    Open-source web app for generating AI-powered summaries of any web page. Paste a URL, select a language, and get concise, markdown-formatted summaries with key tags.

    Next.jsReactShadcn UIGemini AI (Google)Tailwind CSSTypeScript
    View details Project Link GitHub Repo

  • URL Shortener

    Simple, open-source web app for creating human-readable shortened URLs and QR codes.

    Next.jsReactTailwind CSSTypeScriptVercel KV (Redis)
    View details Project Link GitHub Repo