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Professional file · Universo TJSX
Software Developer
Hands-on full-stack profile with projects in production. I build published websites, mobile apps, Windows desktop tools and video games, with attention to maintainability, deployment and user experience. I also provide software technical support.
Desktop + Web · In institutional use · CECATI 106 Los Cabos
Full enrollment system for a Mexican public technical school, replacing a paper-and-spreadsheet process with a verifiable digital record. Applicants enroll online and upload their documents; the Records Office imports, reviews and resolves each case from a desktop application: a 12-state workflow, transactional institutional folio, atomic seat reservation so two applicants can never take the same slot, encrypted backups (AES-256, Encrypt-then-MAC, PBKDF2) and a full audit log. Modular monolith in layers, with a domain layer that has no external dependencies. 18,367 lines, 52 endpoints and 47 automated tests passing. Internal system, no public access.
C# · .NET 10 · ASP.NET Core (Minimal APIs + Razor Pages) · WPF (MVVM) · Entity Framework Core · PostgreSQL · SQLite · Supabase · Docker · Render · xUnit
Web · In production
Institutional website for a Mexican public vocational training centre (SEP) that replaces the in-person enrollment process with an online flow wired into the school's records system: a 6-step form capturing the full official SI-01 record, CURP validation with the RENAPO check digit, document verification by binary signature and in-browser image compression (a 3.4 MB photo drops to 361 KB). It also includes a 24-course catalog, a vocational test, a virtual assistant with a custom NLP engine (33 intents, hand-written Levenshtein distance) answering with live catalog data, and an accessibility system with dark mode, high contrast and text scaling. Built with vanilla HTML, CSS and JavaScript on Supabase — no frameworks, no bundler and zero npm dependencies. Security lives in Row Level Security policies: applications can be submitted but never read by others.
HTML5 · CSS3 (layered architecture) · Vanilla JavaScript · ES Modules · Supabase (PostgreSQL · PostgREST · RLS · Storage) · Canvas API · Pointer Events · WAI-ARIA · JSON-LD · Netlify · 0 npm dependencies
→ View live siteWeb · In production · Custom domain · CI/CD
Progressive web app built for the moment something is already happening: emergency mode, a configurable action button (personal alarm, local evidence recorder, chained SOS), verified legal guidance with real laws, articles and all 32 Mexican state prosecutor offices, first aid for people and pets, mental health tools, a community map, life QR codes, adoptions, reports and a social layer. Custom engineering: a deterministic assistant that works with no AI and no connection, an in-house translation engine for 130+ languages that never sends what users write, and file transfer between phones over animated QR using fountain codes. 55,852 lines of TypeScript, 403 unit tests and 53 end-to-end tests, with WCAG 2.1 AA accessibility auditing. Free, with no payments. It does not replace emergency services or professionals.
Next.js 16 · React 19 · TypeScript · TailwindCSS · Supabase (PostgreSQL · RLS · Realtime) · MapLibre GL · PWA / Service Worker · IndexedDB · WebGPU (WebLLM) · Vitest · Playwright · axe (WCAG 2.1 AA) · Netlify · CI/CD · DNS · HTTPS
→ View live siteWeb · In production · Custom domain · CI/CD
One-page site combining a professional portfolio, technical projects, music, horror content and social links. Custom offline chatbot, screenshot lightbox, SEO and continuous deployment from GitHub.
HTML · CSS · JavaScript · SEO · UI/UX · Netlify · DNS · HTTPS
→ View live siteDesktop (Windows) · Real product, internal use
Audio mastering engine with AI-assisted analysis: integrated LUFS, True Peak, LRA and spectral balance; profiles such as Streaming Safe -14 LUFS, automatic mastering plans, licensing system and export. Used in production for the KIDJSX discography. Private application, no public link.
Python · Audio DSP · AI · Windows · Licensing
Desktop (Windows) · Real product, internal use
Turns music into publish-ready MP4 videos: circular spectrums, synced audio, cinematic backgrounds and vertical presets. Exports H.264 + AAC 1080p through FFmpeg. Local-first architecture: no login, no cloud, no telemetry. Private application.
FFmpeg · Video generation · Audio · Local-first
2026 — Present · School enrollment and records system
End-to-end design and development of the system that replaced the school's paper enrollment process: ASP.NET Core API (52 endpoints), public Razor Pages portal, WPF/MVVM desktop app for the Records Office, Entity Framework Core over PostgreSQL (Supabase) with SQLite contingency mode, Docker/Render deployment, encrypted backups and an audit log. Layered modular monolith with 47 automated tests.
2026 — Present · San José del Cabo, Mexico
Institutional landing page for student enrollment, with a course catalog, events, location details and a responsive experience. Published site.
Published project on a custom domain
Progressive web app for animal protection and human safety, in production on a custom domain: emergency mode, configurable action button, verified legal guidance, first aid, mental health tools, community map, life QR codes, adoptions and a social layer. Next.js 16, React 19, strict TypeScript and Supabase with Row Level Security and Realtime; deterministic offline assistant with no AI; PWA with service worker and deferred sync. 403 unit and 53 end-to-end tests, plus automated accessibility auditing.
2025 — Present
Portable Windows tools: audio mastering (Python/AI, LUFS and True Peak measurement) and music video generation (FFmpeg). Local-first architecture and applied security.
2024 — Present · Veracruz, Mexico
Web, mobile and desktop solutions: authentication, databases, REST APIs, local storage and deployment, with a focus on maintainability, applied security and user experience.
Primary use (published projects or real products)
Hands-on project experience
Familiarity
Classification based on actual usage in the projects listed above. No percentages or skill bars: the published evidence is the best reference.
Professional complement: basic technical support and software maintenance on Windows machines — OS installation, formatting, backups, drivers, configuration, antivirus, software error diagnostics and corrective software-level maintenance.
Instituto Tecnológico de Veracruz · 2019 — 2025
Program completedSpanish: native · English: advanced
Academic milestone
Formal completion of my studies in Computer Systems Engineering at the Instituto Tecnológico de Veracruz, closing an academic stage and continuing my professional development in engineering and software development.
Work email: lajjmex117@gmail.com (replies within 24 hours).
Phone number and access to private repositories are shared privately during recruitment processes.
Idioma · Language
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