https://pablorejon.com/blog DevLog, technical engineering notes, and active project chronicles by Pablo Rejón. en-us Mon, 14 Sep 2026 12:00:00 +0000 https://pablorejon.com/images/icon-192.png https://pablorejon.com/blog https://pablorejon.com/blog#incorporacion-indexa-capital-software-engineer-intern https://pablorejon.com/blog#incorporacion-indexa-capital-software-engineer-intern Mon, 14 Sep 2026 12:00:00 +0000
Key Updates:

• 1. Intentional Search: Why Indexa Capital: Joining a company with an exemplary engineering culture and a product I already used and believed in, guided by radical transparency and automated indexing.
• 2. The Selection Process During the Málaga Cyber Bootcamp: Balancing the intense training schedule at the Google/UMA Cyber Bootcamp with the technical interview rounds.
• 3. Onboarding on September 9: Backend & Agentic AI: Officially joining on September 9th, learning fault-tolerant patterns, scalable backend systems, and integrating agentic AI in daily developer workflows.
• 4. Goals & Continuous Learning: Delivering value from day one, preparing thesis defense, and growing as a software engineer.

]]> pablo@pablorejon.com (Pablo Rejón) https://pablorejon.com/blog#organizator-pack-empresa-open-banking-invitaciones-ux-movil https://pablorejon.com/blog#organizator-pack-empresa-open-banking-invitaciones-ux-movil Sun, 13 Sep 2026 12:00:00 +0000
Key Updates:

• 1. Enterprise Suite (v1): Multitenant Architecture & Collaborative Kanban: Transforming Organizator into a collaborative multi-tenant workspace with strict tenant isolation and optimistic concurrency control:
• 2. PSD2 Open Banking: Frictionless Connection & Quota Protection: Complete overhaul of the Enable Banking integration, eliminating technical jargon while safeguarding API usage quotas:
• 3. Cryptographic Invites & Closed Beta Gateway: Replacing manual temporary passwords with cryptographic onboarding links and invite-only beta requests:
• 4. Gesture-Based Mobile Navigation (Swipe), «My Account» & Maskable Logo Geometry: Ergonomic mobile refactor for touchscreens and resolving geometric clipping on the official brand emblem:
• 5. Engineering Rigor: Enforced pnpm, CI/CD Probes & 100% Test Coverage: Hardening development standards and continuous automated verification on production pipelines:

]]> pablo@pablorejon.com (Pablo Rejón) https://pablorejon.com/blog#organizator-redisenio-interfaz-nuevo-logo-identidad-movil https://pablorejon.com/blog#organizator-redisenio-interfaz-nuevo-logo-identidad-movil Thu, 03 Sep 2026 12:00:00 +0000
Key Updates:

• 1. New Brand Identity & Symbolism of the Brain: Introducing the new official logo of Organizator, designed as a modular circular wheel integrating the 5 core facets of personal management:
• 2. Complete UI Restructuring: Mobile-First Ergonomics: Restructuring the UI starting from the mobile viewport to maximize speed and clarity during daily tracking:

]]> pablo@pablorejon.com (Pablo Rejón) https://pablorejon.com/blog#organizator-sincronizacion-multidispositivo-offline-invoicing-pdf https://pablorejon.com/blog#organizator-sincronizacion-multidispositivo-offline-invoicing-pdf Wed, 02 Sep 2026 12:00:00 +0000
Key Updates:

• 1. Cross-Device Synchronization & Offline Persistence: Diagnosing and fixing cross-device state drift between mobile and desktop clients when updating tasks and calendar schedules:
• 2. PDF Invoicing Pipeline & UI Refinement: Hardening the invoicing suite and visual cleanup of core operational components:
• 3. Cashflow Domain Modeling: Invoices Over Naive Recurring Flows: Refactoring financial cashflow projections by retiring a simplistic abstraction that triggered false overdue warnings:

]]> pablo@pablorejon.com (Pablo Rejón) https://pablorejon.com/blog#caso-de-estudio-servicios-infraestructura-redisenio https://pablorejon.com/blog#caso-de-estudio-servicios-infraestructura-redisenio Tue, 01 Sep 2026 12:00:00 +0000
Key Updates:

• 1. Backend: Self-Hosted Contact API on VPS (Zero Third Parties, 100% GDPR): Radical replacement of third-party form processors (Formspree, Typeform, Google Forms) with a self-hosted microservice ensuring customer data never leaves sovereign infrastructure:
• 2. Frontend: Performance, Accessibility & Mobile-First UX: Interaction engineering focused on frictionless usability, accessible keyboard navigation, and graceful degradation:
• 3. Value Proposition, Conversion Copywriting & Dual-Market Strategy: Transparent communication tailored for technical trust and regulatory differentiation:
• 4. Production Metrics, Security & Conversion Results: Technical and operational impact following production deployment:

]]> pablo@pablorejon.com (Pablo Rejón) https://pablorejon.com/blog#organizator-modulo-fiscal-hac-773-multicargo-multiuser https://pablorejon.com/blog#organizator-modulo-fiscal-hac-773-multicargo-multiuser Mon, 31 Aug 2026 12:00:00 +0000
Key Updates:

• 1. Freelance Tax Module & Official Spanish Tax Ledgers (HAC/773/2019): Architecture and design of regulatory tax ledgers compliant with Spanish Order HAC/773/2019 with reactive synchronization between income tax and VAT:
• 2. Smart Financial Engine: Recurring Expenses & Multi-Charge Matching: Advanced bookkeeping automation for periodic expenses and split billing obligations:
• 3. Multi-User Scaling & Security Architecture: Platform evolution to support multiple real active users managing their personal finances on the application daily:

]]> pablo@pablorejon.com (Pablo Rejón) https://pablorejon.com/blog#organizator-web-push-debugging-tres-fallos-silenciosos https://pablorejon.com/blog#organizator-web-push-debugging-tres-fallos-silenciosos Sun, 30 Aug 2026 12:00:00 +0000
Key Updates:

• 1. The Architecture & The Three Chained Silent Bugs: The event notification selector stored values in the database but relied exclusively on ICS calendar alarms. The goal was true background Web Push delivery with the app closed, uncovering three layered silent bugs that produced no error logs:
• 2. Debugging Timeline, Idempotency & Takeaways: From the initial UTC container discovery at 23:04 to verified delivery at 12:00:17 with registered idempotency keys:
• 3. Extension: Overdue Milestone Warnings, Calendar Banner & Daily Planner Integration: After stabilizing the push notification pipeline, we expanded the engine to cover project milestones with a noise-free alert policy, while synchronizing warning banners and events directly into the Calendar and Daily Planner:

]]> pablo@pablorejon.com (Pablo Rejón) https://pablorejon.com/blog#lanzamiento-servicios-informatica-desarrollo-web-empresas https://pablorejon.com/blog#lanzamiento-servicios-informatica-desarrollo-web-empresas Sat, 22 Aug 2026 12:00:00 +0000
Key Updates:

• 1. Professional Philosophy & Value Proposition: A proposition designed to handle small business web presence with rigor, transparency, and full legal guarantees.
• 2. Bespoke Web Development & Managed Maintenance: Comprehensive services backed by hands-on experience running production infrastructure and live e-commerce platforms.

]]> pablo@pablorejon.com (Pablo Rejón) https://pablorejon.com/blog#art-gallery-advanced-seo-web-vitals-overhaul https://pablorejon.com/blog#art-gallery-advanced-seo-web-vitals-overhaul Sat, 22 Aug 2026 12:00:00 +0000
Key Updates:

• 1. Crawlable Links, Schema.org & Pre-rendered HTML: Restructuring catalog rendering so Googlebot autonomously indexes every artwork without relying on client-side JavaScript execution.
• 2. Google Images Sitemap & Bundle Size Optimization: Maximizing load speed and visual discovery on Google Images search and Cloudflare Web Analytics.

]]> pablo@pablorejon.com (Pablo Rejón) https://pablorejon.com/blog#organizator-autonomo-fiscal-module-architecture https://pablorejon.com/blog#organizator-autonomo-fiscal-module-architecture Fri, 21 Aug 2026 12:00:00 +0000
Key Updates:

• 1. Official Tax Ledgers & Persistent Schema: Strict accounting domain modeling compliant with freelance tax requirements under direct simplified taxation.
• 2. PDF Engine: Base-14 Standard Font Optimization in pdfmake: Client-side standard invoice generation reducing embedded font bundle size from 1 MB to 281 KB with ReportLab-identical typography.
• 3. Reactive Bridge 'My Work' ➔ Automated Billing: Automating the invoicing workflow directly from completed client projects without transaction duplication or treasury desync.
• 4. Cryptographic Chaining & Fiscal Traceability: VeriFactu & QR: Preparing the platform for the regulatory requirements of the Spanish VeriFactu billing system (immutability, hash chaining, and QR verification).
• 5. Live Quarterly Tax Settlement: Models 303 & 130: Real-time financial visibility to project VAT and Personal Income Tax liabilities and eliminate tax quarter surprises.

]]> pablo@pablorejon.com (Pablo Rejón) https://pablorejon.com/blog#organizator-fitness-module-architecture https://pablorejon.com/blog#organizator-fitness-module-architecture Thu, 20 Aug 2026 12:00:00 +0000
Key Updates:

• 1. UX Ergonomics: Zero Friction in the Gym (Mobile vs Desktop): On the gym floor, every superfluous interaction competes with workout fatigue: we strictly decoupled the high-velocity mobile flow from deep desktop analytics.
• 2. Multi-Day Weekly Planning & Reactive Calendar: A bidirectional bridge between athletic periodization and personal calendar management, breaking down isolated application silos.
• 3. Smart Auto-Population Algorithm: Zero Load Friction: Heuristic target calculations so athletes never have to recall past personal bests or consult spreadsheets between sets.
• 4. Template Architecture & Native SVG Charts: Expanding Organizator's P.A.R.A. engine and reusing lightweight visual primitives without bloating the application bundle with third-party chart libraries.
• 5. Dogfooding & Conclusions: The Unified P.A.R.A. Ecosystem: Why a truly unified Second Brain vastly outperforms a fragmented stack of four dedicated niche applications.

]]> pablo@pablorejon.com (Pablo Rejón) https://pablorejon.com/blog#triajia-clinical-architecture-refactor-testing https://pablorejon.com/blog#triajia-clinical-architecture-refactor-testing Wed, 19 Aug 2026 12:00:00 +0000
Key Updates:

• 1. Modular Decomposition of TriageWorkspace: We transformed the 1500+ line monolithic component into a decoupled ~225-line orchestrator, isolating pure clinical logic into specialized hooks and reusable card components.
• 2. Clinical UX, Dispositions & Isolation: We designed a realistic emergency workflow tailored to hospital roles, establishing clear boundaries between waiting-room triage and the hospital's central HIS.
• 3. HIS Integration (HL7 / FHIR Webhooks): We equipped TriajIA with hospital interoperability capabilities through secure, asynchronous webhooks compatible with global standards.
• 4. Security, Multi-Tenant Hardening & Bug Fixes: We hardened the platform against cross-tenant data leaks and stabilized the infrastructure for continuous deployments.
• 5. Automated Test Suite & Academic Thesis Docs: We implemented comprehensive test coverage with Vitest and organized technical documentation in docs/ as a robust foundation for the thesis defense.

]]> pablo@pablorejon.com (Pablo Rejón) https://pablorejon.com/blog#vps-resource-optimization-art-gallery-domain https://pablorejon.com/blog#vps-resource-optimization-art-gallery-domain Tue, 11 Aug 2026 12:00:00 +0000
Key Updates:

• 1. Decommissioning Football Manager: We decided to decommission the Football Manager project from production due to its high RAM and disk storage footprint, prioritizing active applications.
• 2. Production: acamachoart.com: We configured and deployed the Art Gallery (Bramasole) under the commercial domain acamachoart.com, enabling routing, HTTPS, and secure CORS.

]]> pablo@pablorejon.com (Pablo Rejón) https://pablorejon.com/blog#new-custom-domain-setup https://pablorejon.com/blog#new-custom-domain-setup Mon, 03 Aug 2026 12:00:00 +0000
Key Updates:

• 1. Cloudflare Registrar & DNS Configuration: I purchased the pablorejon.com domain via Cloudflare Registrar for its fair pricing and control panel, consolidating my DNS resolution for my entire infrastructure.
• 2. VPS Migration & Caddyfile Updates: Reconfigured the Caddy web server on my VPS to route all projects and sub-applications under the new domain with automatic HTTPS.
• 3. Professional Email Setup with Zoho: Established my custom professional email address by linking the domain to Zoho Mail using verification and security records.

]]> pablo@pablorejon.com (Pablo Rejón) https://pablorejon.com/blog#data-loss-recovery-backups https://pablorejon.com/blog#data-loss-recovery-backups Fri, 17 Jul 2026 12:00:00 +0000
Key Updates:

• 1. Diagnosis: Ephemeral Postgres & Sync Wipe Effect: The production system suffered a complete wipe. The root cause analysis revealed a Docker volume misconfiguration and a flaw in our state synchronization protocol.
• 2. The Rescue: LevelDB Forensic Extraction (Brave): We recovered a database dump from June 9, but to save the data from June and July, we conducted a forensic extraction from Brave's local storage files.
• 3. Prevention: Safeguards, Triggers & Encrypted Backups: To immunize the system against future incidents, we designed and implemented a three-tier protection architecture across the backend, database, and external backups.

]]> pablo@pablorejon.com (Pablo Rejón) https://pablorejon.com/blog#visita-gsec-google-malaga https://pablorejon.com/blog#visita-gsec-google-malaga Wed, 15 Jul 2026 12:00:00 +0000 pablo@pablorejon.com (Pablo Rejón) https://pablorejon.com/blog#repon-nfc-pwa-grocery https://pablorejon.com/blog#repon-nfc-pwa-grocery Tue, 14 Jul 2026 12:00:00 +0000
Key Updates:

• Boot Plan: Architecture & Roadmap: I have defined the project structure and the development plan split into three incremental phases to achieve a functional MVP.
• Phase 3 Completed: Successful Deployment & Resolving Caddy/Vessel Conflicts: The project is now fully developed! We overcame a critical networking hurdle during production deployment with Vessel, and we are now just waiting for the physical NFC stickers to arrive for pantry placement.
• Debugging Vessel: Environment Variable Injection & Admin Access Fix: While trying to access Repón's admin panel, we found that the configured ADMIN_PASSWORD was not being injected. This led us to debug and enhance Vessel, our custom PaaS, resolving issues on both client and server sides.
• Reactive Checkout & Env Var Interpolation in Vessel: We added two critical enhancements for usability and security: an interactive checkout flow that atomically clears the database and dynamic secret interpolation in Vessel.

]]> pablo@pablorejon.com (Pablo Rejón) https://pablorejon.com/blog#sync-revolut-organizator https://pablorejon.com/blog#sync-revolut-organizator Sat, 11 Jul 2026 12:00:00 +0000
Key Updates:

• Phase 1: Real-Time Bank Sync (PSD2 / Open Banking): To solve this challenge, I designed and integrated a real-time banking synchronization system using the Enable Banking API (AISP - Open Banking / PSD2) to securely connect Organizator's backend with Revolut.
• Phase 2: Reconciliation & Refund Tracking: To boost the utility of the bank sync, I designed and implemented a Reconciliation Module for Shared Expenses (Bizums / Shared Costs) to manage pending refunds automatically without duplication.
• Phase 3: 1-to-N Flexible Reconciliation Engine & Mobile-First UX: To solve the issue of shared expense tracking (Bizums inflating income and distorting expenses), I designed and implemented a flexible 1-to-N reconciliation engine and an optimized mobile UX.
• Phase 4: Financial Reengineering, Projections & Smart Reconciliation: We performed a deep restructuration of Organizator's financial module, simplifying the UI, implementing a future net worth projection engine, and refining transaction reconciliation & amortization.

]]> pablo@pablorejon.com (Pablo Rejón) https://pablorejon.com/blog#blog-start https://pablorejon.com/blog#blog-start Fri, 10 Jul 2026 12:00:00 +0000 pablo@pablorejon.com (Pablo Rejón)