Isidro Zertucha
Independent Full Stack Engineer · End-to-End Product Ownership
Engineer with production work at million-user scale and the pace of 30-day fintech launches. I take products from blank repo to production — architecture, implementation, infrastructure, and the decisions in between.
Sectors I've delivered for
How I help
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Mobile
Cross-platform apps with offline-first sync, local caching, and field-grade reliability in real connectivity gaps.
Flutter Dart SQLite REST GitLab CI/CD -
Frontend
Production-grade interfaces from scratch to deployment, pixel-perfect Figma implementation, and Shopify embedded apps when needed.
React Next.js Remix.js TypeScript Shopify -
Backend
Services and persistence architected with Clean / Hexagonal layering when complexity warrants it, otherwise pragmatic.
FastAPI Nest.js Django Spring Boot PostgreSQL -
Infrastructure & Ops
Owning the deploy cycle — provisioning, securing, observing — without becoming a full-time DevOps engineer.
Docker Cloudflare GitLab CI/CD Hetzner Heroku -
AI integration
Wiring frontends against agentic backends — RAG retrieval, LangGraph flows, and queue-driven LLM jobs over Redis.
LangGraph Pinecone Redis OpenAI Groq -
Automation
SignatureIndustrial automation engineering background — flow-based integrations when the project genuinely calls for it.
Node-RED n8n OPC-UA OpenCV Python
Work Experience
- Sep 2025 — Sep 2026
Full Stack Engineer
Avangenio (General Software Inc.)Proposed, designed and built the offline-first Flutter courier app for Muévete y Cocina — a fuel & cooking-gas marketplace — and shipped extensively on its customer web app (React Router + Vite) alongside the team's frontend lead and a designer. Went full stack on it as it grew: FastAPI delivery-evidence and a server-enforced dispatcher-to-servicentro authorization boundary, a per-brand legal-document system, and a pre-release security audit that closed a PIN-lock bypass letting a failed unlock inherit the live session. The team has since white-labelled the platform, which now sells under two brands, Mercaful and Gasolero. Also contributed to a Salary & Treasury ERP on a FastAPI + Next.js 16 monorepo (currency-exchange admin modules), Linkeum Wallet for Tropipay (multi-currency, 30 days, two engineers), and a Flutter justice-system field app integrated with an ERPNext/Frappe backend.
FastAPI Next.js Nest.js Flutter Turborepo PostgreSQL Python - Sep 2023 — Sep 2026
Software Engineer
Etecsa · Central IT DirectorateNational-scale telecom platforms serving 7M Cuban subscribers. Built the Nauta Flutter app end-to-end as the sole mobile developer, so subscribers could manage their internet plan and captive-portal access from one place. Also ran the Javax-to-Spring-Boot evaluation: ported one internal module and benchmarked it against the legacy stack with SoapUI — roughly 3× faster — giving the platform decision hard evidence.
Java Spring Boot Flutter Nest.js PostgreSQL Docker - Jun 2025 — Aug 2025
Lead Full Stack Developer (Freelance)
RanfoSole technical owner for the end-to-end digitization of a vehicle workshop. Provisioned Hetzner VPS + Dokploy + Cloudflare. Executed a non-breaking schema migration in flight to support multi-currency payment splitting, with zero downtime.
Django PostgreSQL Dokploy Hetzner Cloudflare GitLab CI/CD - Jun 2024 — Aug 2024
Full Stack Developer · Frontend Lead
Yula (France · Remote freelance)Built the public surface for an AI customer-service product for Shopify — landing + Shopify embedded app in a single Remix codebase, integrated against a LangGraph + Pinecone + Redis backend. Owned the Heroku deployment cycle.
Remix.js Shopify Prisma FastAPI Heroku - Apr 2024 — May 2024
Frontend Developer
Pakkete GroupStabilized a Flutter e-commerce platform for production launch. Worked across a multidisciplinary team — backend, UI/UX, marketing — to align the final technical delivery with brand identity and the launch window.
Flutter Dart - Aug 2023 — Feb 2024
Lead Full Stack Developer (Freelance)
L&M Tailoring (Sastrería Stein)Solo-engineered a Django + PostgreSQL central server plus Flutter mobile clients to replace 100% of the workshop's paper-based ordering and bookkeeping. Configured the on-prem LAN so the floor staff and the office synced in real time with zero data loss.
Django Flutter PostgreSQL Linux - 2022 — 2024
IT Project Lead (Contract)
CUJAEEngineered an automated, Linux-based campus security system on Raspberry Pi nodes using Python and OpenCV for real-time identity verification via QR codes. Integrated the edge hardware with a Node-RED backend over REST APIs in collaboration with the Informatics department.
Python OpenCV Node-RED Raspberry Pi Linux Docker - 2019 — 2021
Community Lead & Systems Admin (Part-Time)
Joven ClubAdministered TeamSpeak voice infrastructure and Xenforo / WordPress community platforms for a national user base — permissions, security policy, database backups. During COVID lockdowns, designed and moderated virtual social programs and interactive quiz shows for at-home users.
WordPress PHP MySQL Linux
Selected work
Source code from most projects stays with the original clients. The case studies cover what's shareable, with full context.
Academic background
Automation Engineering
- Honors
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- Scientific Merit Award — outstanding academic and research performance, CUJAE (2023).
- Integrality Award — well-rounded academic, social, and extracurricular standing, CUJAE (2023).
- Teaching positions
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- Teaching Assistant — Automation & Programming, CUJAE (2019 – 2023)
- Robotics Instructor — GRM CUJAE (2019 – 2023)
- Undergraduate Thesis Advisor — CUJAE / ICIMAF (Dec 2024 – Mar 2025)
- Publications (2023)
An engineer for products that need ownership, not just a contractor.
I'm a full stack engineer with a generalist view of software development. I've worked primarily on the frontend because that's what the products and teams I joined required, but I'm equally comfortable designing architecture, building services, deploying infrastructure, and making end-to-end technical decisions.
I graduated as an Automation Engineer from CUJAE (2018–2023). That training taught me to understand systems as a whole — analyzing constraints, identifying dependencies, and designing robust solutions. That approach still shapes the way I write software.
I take on two or three concurrent projects at most to keep focus and quality. I prioritize asynchronous communication, complement it with structured meetings when they add value, and document the important decisions as the project evolves. If you're looking for someone who can take charge of a problem from start to finish, we'll probably work well together.