Product builder & technology lead
I’m Manuel Castillejo. I connect engineering, product and the way people work. Today, I’m building FlowSight. This is the work that brought me here.
Currently building
FlowSight: local AI for understanding digital work.
The thread through my work
My path has moved through games, intergenerational living, AI tools and business workflows. The common thread is turning a real problem into something people can use.
I have worked as a technology lead and from the perspective of business process management. That means understanding the architecture and the people who live with it: their routines, friction and decisions.
FlowSight brings those interests together. I’m building software that helps people understand their work while keeping detailed context close to them. Along the way, I keep making, learning in teams and writing about attention.
Selected work
Creator / product & engineering
What does a working day actually look like? FlowSight analyzes work context locally and turns it into summaries and patterns people can review. I work across the product, desktop application and wider ecosystem.
The University of Seville recognized FlowSight for innovative impact in 2026. Development also took me to Xiji Incubator in Shanghai.
Team project / Startup Weekend 2025
We built a conversational assistant for pet care, connecting natural-language questions with recommendations on training, nutrition and wellbeing. KahuPet won first place and the cybersecurity recognition at Startup Weekend Sevilla.
Team project / NASA Space Apps 2025
With an international Innovators Hub team, we built an educational exploration prototype. Interactive missions and simulations turn space curiosity into a learning experience.
3D assets / Scopely Game Jam 2023
A game made with the Jamongus team, under game-jam constraints. I contributed 3D assets; together, we won first place.
My story
2020+
Software engineering studies at the University of Seville’s ETSII formed the foundation: programming, algorithms, databases and teamwork. Alongside that, I explored 3D and interactive experiences.
2022-2023
I worked on games and 3D assets, then built All The Way UP with Jamongus. We took first place at Scopely Game Jam 2023, an early lesson in shipping with a multidisciplinary team.
2024-2025
As CTO at CoNest, I worked on the digital platform for intergenerational living. Fuzzy C-Shell, Pawtel and other projects extended my practice in algorithms, full-stack systems and collaborative product development.
2025
KahuPet won Startup Weekend Sevilla and its cybersecurity recognition. I worked on UNSENT, local AI experiments, study tools and notarial systems, while connecting technical architecture with the realities of people’s work.
2025
Through Innovators Hub I attended Al-Andalus Innovation Venture and joined NASA Space Apps Challenge with an international team. GALAX brought together education, simulations and space exploration.
2026
Selected for the spring Xiji Incubator program, I developed FlowSight in Shanghai. In June, the University of Seville recorded the project’s innovative-impact award. The ecosystem now includes desktop, mobile and practical resources.
2026
Ogathon 4.0 added a team silver medal in AI to my cybersecurity practice. I continued exploring organizational intelligence and published Room 61, a newsletter about attention, focus and the tools we build.
Project collection
Products, experiments and collaborative work. Each entry links to its public source.
26 projects
Desktop work intelligence: local analysis, reviewable summaries and patterns of focus, meetings and interruptions.
Rust / Tauri / local AI
A mobile companion in the FlowSight ecosystem, with work activity and personal context for iOS and Android.
React Native / TypeScript
A team-built pet-care assistant with natural-language recommendations for training, nutrition and wellbeing.
TypeScript / conversational AI
An intergenerational living platform connecting students and older adults around mutual support.
TypeScript / web platform
An experimental digital storytelling project built around unsent messages, reflection and private AI.
TypeScript / AI / storytelling
An educational space-exploration prototype created for NASA Space Apps with the Innovators Hub team.
Next.js / TypeScript / simulations
The Jamongus team game that won Scopely Game Jam 2023. My contribution included 3D assets.
Unity / C# / Blender
A collaborative comparison and booking platform for pet hotels, with publicly documented contributions.
Django / Vue / collaborative project
Document-copy tracking for notarial workflows, using QR codes and office locations for traceability.
Next.js / MongoDB / QR
An AI-assisted notarial management system organized around document and operational workflows.
TypeScript / AI / workflow
A browser extension that processes text with local language models directly on the device.
WebLLM / WebGPU / WASM
A study tool that analyzes past exams and generates personalized study guides.
TypeScript / AI / MongoDB
An implementation of fuzzy clustering, with a synthetic dataset generator for experiments.
Python / clustering
A CRUD web application with natural-language access to a database through MCP integration.
Node.js / Express / MongoDB / MCP
A Nostr social client exploring AI-assisted workflows through Model Context Protocol servers.
Nostr / TypeScript / MCP
An exploration of tool integration through the Model Context Protocol.
TypeScript / MCP
Natural-language dish recommendations based on what a person wants to eat.
TypeScript / recommendations
A community web platform for innovators and digital nomads in Seville.
TypeScript / community
A multiplayer card-game implementation with social features, achievements and rankings.
Java / real-time multiplayer
A Blender project from the early 3D and visual-creation chapter of my work.
Blender / 3D
A structured set of commented signal-processing exercises in Octave.
Octave / MATLAB
A public-facing website extending the work on digital experiences for professional services.
TypeScript / web design
An experimental AI-assisted journaling project submitted to Katy Youth Hacks 2025.
Next.js / TypeScript / journaling
An event-platform concept connecting NFC networking, cashless payments and social gamification.
TypeScript / NFC / events
A pre-registration website for an NFC smart-card concept for professional connections.
Next.js / TypeScript / NFC
A barber-app prototype exploring face-shape analysis and personalized haircut recommendations.
Flutter / Dart / ML Kit
Recognition
2026
Cámara de Comercio de Sevilla & La Fábrica de Sevilla
FlowSight, XXI Entrepreneurship Ideas Competition at the University of Seville.
Read source2025
Startup Weekend Sevilla / INCIBE Emprende
KahuPet, with a six-person founding team.
Read source2023
Scopely Game Jam
All The Way UP, with the Jamongus team.
Read source2026
Ogathon 4.0 / OGA.ai
An interdisciplinary team combining engineering, mathematics and cybersecurity.
Read sourceLearning & practice
Software engineering studies at ETSII, University of Seville. My earlier portfolio also records learning in AI ethics through Lund University, game development through UNED, and continuous delivery and DevOps through the University of Virginia.
Earlier portfolio sourceMy public work spans Rust and Tauri, TypeScript and web development, Python and machine learning, Unity and Blender, databases and MCP integrations.
I also explore Organizational Intelligence Engineering through OIE Labs: connecting strategy, people and technology.
OIE LabsWriting
Personal newsletter
Room 61 is where I write about attention, focus, personal experience and the tools we build. A more personal view of the questions behind the software.
Read Room 61On YouTube, I share presentations and experiences from the entrepreneurship journey, including the FlowSight pitch in Shanghai.
Watch the FlowSight pitchLet’s talk
For product conversations, technical collaboration or a good exchange of ideas, you can reach me directly.