Full-Stack Developer — React · Next.js · TypeScript · Node.js — based in Barcelona, Spain 🇪🇸
I'm a frontend-focused full-stack developer specialized in building UI/UX-driven SaaS products, internal platforms, and creative tools. I bring a disciplined, detail-oriented approach to how I work: careful about the details, honest about trade-offs, and always looking to improve
I recently completed a 6-month engagement at JPL Media, building Positive Duty v2 — a multi-tenant compliance training platform serving 70+ organizations across Australia.
Positive Duty v2 — JPL Media
Multi-tenant compliance training platform for Australia's Respect at Work legislation, serving 70+ organizations. Designed and built the UI architecture, role-based portals, and an automated reminder engine for annual reviews, using composite idempotency keys.
Next.js React TypeScript Tailwind CSS Prisma PostgreSQL Keycloak Kubernetes
(Client project — code is private; full case study on my portfolio)
Full-stack multimedia platform documenting extended bandoneon techniques — sound library, video demos, articles, and podcast. Built an end-to-end audio pipeline (WAV/MP3 ingestion, Cloudinary conversion, cursor-based pagination, custom WaveSurfer.js player).
Next.js React TypeScript Tailwind CSS MySQL Vercel
Conta — Accounting & Tax Automation
A CLI/TUI tool for Spanish freelancers to manage invoices, deductible expenses, and quarterly IVA/IRPF tax reports, with a typed domain model and Decimal-precision arithmetic to avoid fiscal rounding errors.
Python SQLModel SQLite Typer Rich
Multilingual brochure site for a Finnish wellness practitioner, with a custom vanilla-JS i18n system (Finnish, English, Swedish) — no framework, no build step.
HTML CSS JavaScript Cloudflare Pages
More projects and full case studies → mkrapo.dev
When I'm not writing code, I'm playing bass and upright bass — jazz, pop rock, traditional, and folk music. That background is where the discipline and attention to detail in my engineering work comes from.