Mario Castaño· Back to top
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Active · Zunibal, Derio

MarioCastaño Romeo

Full stack software engineer

Ten years designing, deploying, and maintaining software built for whatever comes next.

ProjectsContact

Career course

Course
Stage
340
Sounding (m)
Isobath
Career chart: Bilbao (Eurohelp, 2015) → New York (Thunderfoot, 2019) → Getxo (Ubikare, 2021) → Derio (Zunibal, 2022, current position).

About

I’m a full-stack software engineer. For the past decade, I’ve been designing and leading web and mobile applications from start to finish across industries as diverse as healthcare, education, banking, and the maritime sector.

My daily work revolves around React/Next.js, Node.js, PHP, and Flutter, but my role doesn’t end with code. I combine technical architecture with team management and direct client communication—a balance that, in practice, is often what determines whether a project stalls or actually hits production.

Currently, I lead the fishery traceability and sustainability solutions at Zunibal, supporting fleets worldwide.

Stack

Frontend
React · Next.js · Vue.js · JavaScript · TypeScript · ClojureScript · HTML5 · CSS3
Backend
Node.js · PHP · Clojure · Java · REST APIs · JWT · OAuth2
Mobile
Flutter · Dart · React Native · iOS · Android · SQLite · Push notifications
Databases
PostgreSQL · MySQL · Datomic · SQL
DevOps & Architecture
Docker · GitLab CI/CD · Git · Clean Architecture · System Design · MVC · Automated Testing
Geospatial & Mapping
Mapbox · Google Maps SDK · OpenStreetMap · Copernicus · NOAA
AI-Augmented Engineering
MCP server development · Claude API integration · Custom agentic skills
Tools
Figma · Jira · Trello · Miro

Projects

A selection of the projects I've worked on; the rest are in my career history. Tap or hover over a card to see what it's about.

  • Fisheries traceability2025 —· In production

    Zunibal eLogBook

    Zunibal

    Fisheries traceability2025 —· In production

    Zunibal eLogBook

    Zunibal

    Zunibal eLogBook is an electronic fishing logbook that follows every catch from sea to consumer, with a dedicated profile for each link in the chain. It works offline at sea and adapts its workflows to each market's regulations. I designed and built it end to end: Flutter app for iOS and Android, Node.js REST API and PostgreSQL database.

    • Shipowner. Registers vessels, tracks the fleet on a live map, reviews and approves each trip, and monitors sales, revenue and performance.
    • Skipper. Opens each trip with a safety checklist, records catches, discards and incidental catches with their GPS position, and checks the vessel, past trips and maps with FAO areas, marine zones and bathymetry, downloadable for offline use.
    • Fish market. Receives vessels, checks declared catches against what is landed, groups them into lots, records first sale and processing, and issues labels with the traceability QR code.
    • Consumer. Scans the product's QR code to see the vessel, fishing area and gear, and keeps past lookups in a history.

    Since September 2026 a Windows version with touch support is also being distributed, and the admin dashboard with metrics across the whole platform is available.

  • Coastal safety2024 —· In production

    Catch Alert Drumline

    Zunibal

    Coastal safety2024 —· In production

    Catch Alert Drumline

    Zunibal

    Catch Alert Drumline is a catch alert system for the shark control programs of Queensland and New South Wales, now expanding to new areas. When an animal takes the bait, the buoy sends a satellite alert and a response team releases it in under 30 minutes, which improves its chances of survival. The platform centralises, in real time, the position and status of 150+ buoys off the east coast of Australia.

  • Fisheries monitoring2024 —· In production

    REM

    Zunibal

    Fisheries monitoring2024 —· In production

    REM

    Zunibal

    REM (Remote Electronic Monitoring) is an electronic monitoring system for fishing activity. On-board cameras, sensors and GPS record where, when and what is caught, as an alternative to on-board observers, and the platform lets reviewers go through the footage and data from each trip.

  • Digital health2021 — 2022

    NAIHA

    Ubikare

    NAIHA (Natural & Artificial Intelligence Health Assistant) is Ubikare's healthcare software, a Class IIa medical device with 15,000+ licenses deployed. Using automated rules and AI, it turns social, clinical and health data into clinical decision support.

    • Social care. Home care, day centres and telecare.
    • Healthcare. A health record shared across disciplines.
    • Clinical trials. Real-time patient recruitment and follow-up.
    • Impact. According to the company, 40% lower costs and time and 30% fewer care-related errors.

  • Investment banking2018 — 2021

    KBW

    Thunderfoot (Terra)

    Keefe, Bruyette & Woods (KBW) is an investment bank focused on the financial sector: equity research, M&A advisory and trading covering banks, insurers and asset managers.

  • Business & technology consulting2018 — 2021

    SEI

    Thunderfoot (Terra)

    SEI is a business and technology consulting firm that works with companies on strategy, digital transformation, data and change management.

  • IT services for education2018 — 2021

    Vinson

    Thunderfoot (Terra)

    Vinson manages IT infrastructure and cybersecurity for schools across the United States. Based in Ohio and trusted by more than 100 school districts, it runs networks, devices and technical support, protects endpoints with managed detection and response, and trains staff in security awareness. It also advises districts on federal E-Rate funding and handles the reports they file with the state of Ohio.

  • Network infrastructure2018 — 2021

    TTI

    Thunderfoot (Terra)

    Turn-key Technologies (TTI) designs, installs and manages network infrastructure for businesses and public bodies: wired and wireless networks, structured cabling and fibre, cybersecurity, video surveillance and access control. It works across sectors such as healthcare, education, government, manufacturing and data centres.

  • Telephony & contact center2018 — 2021

    natterbox

    Thunderfoot (Terra)

    Natterbox is a telephony and contact center platform built into Salesforce: it routes calls, logs every interaction in the CRM and uses AI to transcribe and analyze conversations.

  • Networking & remote access2018 — 2021

    remote.it

    Thunderfoot (Terra)

    remote.it provides secure access to remote devices and networks, such as industrial IoT equipment, servers or cameras, without opening ports or deploying a traditional VPN.

  • Healthcare marketing2018 — 2021

    PHM

    Thunderfoot (Terra)

    PHM (Publicis Health Media) is Publicis Groupe's healthcare media agency: it plans and buys campaigns for pharmaceutical and health brands using audience data.

  • Public service2015 — 2017

    Bizkaia public transport

    Eurohelp Consulting

    Public service2015 — 2017

    Bizkaia public transport

    Eurohelp Consulting

    A platform serving Bizkaibus, the public bus network run by the Provincial Council of Bizkaia that connects the towns across the province. It was my first professional project: I joined the Eurohelp team as a junior programmer and combined it with the final years of my degree.

Career

  1. 4

    Zunibal

    Senior software engineer, R&D

    Dec 2022 — present

    Derio, Spain

    Current position

    • Develop software solutions for fishing sustainability, traceability and fleet operations across mobile, web, backend, databases and deployment workflows. Built approximately 50% of the company's mobile applications and became the team's primary mobile development reference.

    eLogBook - Fishing Traceability Platform

    • Independently designed and developed a complete fishing-traceability solution from an initial high-level business concept, researching the operational workflows of vessel owners, skippers, fish markets and final consumers.
    • Built a Flutter iOS/Android/Windows application, Node.js REST API and PostgreSQL data model covering vessel registration, fishing trips, catch recording, landing, fish-market processing and final product traceability.
    • Designed an offline-first architecture using SQLite so vessels can keep operating without connectivity at sea and synchronize with the backend once a connection returns.
    • Implemented 55+ screens, 30+ database tables and 100+ API endpoints, including authentication, role-based access, multilingual support, maps and geospatial data.
    • Designed a configurable approach to market-specific regulatory requirements, allowing the same product to adapt its workflows and screens to different international markets.
    • Owned the product end-to-end (database, architecture, user flows, UX/UI and technical documentation) across ~10 months of full-time development and dozens of iterations, and continue to maintain and extend it as new market requirements emerge.

    Catch Alert Drumline - Shark Monitoring & Alert Platform

    • Developed and maintain a full-stack web application and API used in collaboration with Australian government stakeholders to monitor 150+ buoys deployed for shark monitoring, in production since 2025.
    • Built real-time map interfaces showing buoy positions, sensor status and the stages of shark-related incidents, with clear visual indicators for operationally critical events.
    • Continue evolving the platform as monitoring requirements change and new coastal deployment areas are incorporated.

    Other R&D & Engineering

    • Built and maintain Z-Scan, Z-PSA and Autorización Armadores, replacing manual, multi-step workflows with faster, more controlled processes. Z-Scan, for example, swaps manual entry for sequential barcode scanning in seconds.
    • Developed the web application and backend for REM, a Next.js/React platform for reviewing onboard fishing-camera footage, coordinating with the desktop and onboard-systems teams building the wider product.
    • Introduced Docker and automated GitLab CI/CD pipelines (Dockerfiles, Compose configurations, pipeline definitions and environment config for AWS-based deployments) with automated tests running as part of the workflow.
    • Built two custom MCP servers with tools to query live REM and shark-monitoring data, and shared it with the engineering team to speed up day-to-day development and debugging.

    Stack Next.js · Node.js · PHP · Flutter

  2. 3

    Ubikare

    Software engineer

    Nov 2021 — Dec 2022

    Getxo, Spain

    • Contributed to NAIHA (Natural & Artificial Intelligence Health Assistant), a healthcare platform supporting clinical workflows, structured health data and evidence-based decision making.
    • Developed production features in Clojure and ClojureScript working across both implementation and solution design.
    • Worked directly with doctors and nurses in regular functional-analysis sessions, translating clinical requirements into software within a multidisciplinary healthcare and engineering team.
    • Contributed to a platform with 15,000+ deployed licenses; NAIHA/Ubikare currently reports 40% savings in costs and time, 30% prevention of care-related errors, 50% reduction in administrative errors and 80% increase in satisfaction and adherence.

    Stack Clojure · ClojureScript · React · Datomic

  3. 2

    Thunderfoot (Terra)

    Software engineer

    Dec 2018 — Nov 2021

    New York, USA

    • Built 15+ responsive websites for US clients across healthcare, banking, legal, consulting and education, taking projects from initial HTML/CSS/JavaScript through backend development, REST API integration, testing and deployment.
    • Ran several projects in parallel, typically 2-3 months of development followed by long-term maintenance, applying technical SEO, Google Analytics and unit testing with Jest.
    • Delivered a project for an education client incorporating 3D animations with Three.js, introducing techniques later reused across subsequent projects.
    • Worked closely with designers and multidisciplinary development teams, and participated in application deployments.

    Stack PHP · JavaScript · VueJS · jQuery · WordPress · Jest

  4. 1

    Eurohelp Consulting

    Junior programmer

    Sep 2015 — Aug 2017

    Bilbao, Spain

    • Developed software for a public transport platform (Bizkaia) and an EGA exam-preparation education platform using Java Spring, JavaScript, HTML, CSS and SQL, while completing university studies.

    Stack Java · JavaScript · SQL · HTML · CSS

Education

BSc in Computer Engineering — Management and Information Systems

University of the Basque Country (UPV/EHU)

Bilbao School of Industrial Engineering

2012 — 2018

Contact

I’m based in Bilbao. If you need to connect platforms and data, with the security required for an application people depend on, write to me in English or Spanish.

Email
mail@mariocastano.com
LinkedIn
in/mariocastano