Jefferson
00 — Profile

Jefferson Montesdeoca Jordán

Product Engineer focused on AI & backend / Andorra la Vella, Andorra

I build products end to end on Java/Spring backends and maintainable architectures. I use AI where it adds value, with validated data, clear limits, and manual fallbacks.

Get in touchLinkedInSee experience
Location
Andorra la Vella, Andorra
Timezone
CET / CEST--:--:--
Focus
Java 21 · Spring Boot 3 · Hexagonal Architecture · Microservices · Next.js · Claude API · AI agents
Since
2019
01 — About

Who I am, in one paragraph

Andorra · Spain · Remote across European time zones

Six-plus years building production software for banking, legal, and energy: from Spain's leading legal marketplace to Big Data platforms in the energy sector, and today backend architecture and technical management at Andbank. I have led complex migrations, integrated legacy systems, and designed hexagonal and microservices architectures. Outside work, I build several products of my own—some public and live, others private and in development—to keep product, backend, deployment, and applied AI decisions close together.

Currently working with
Java 21Spring Boot 3Hexagonal ArchitectureMicroservicesNext.jsClaude APIAI agents
6+Years of software in production
3Industries · banking, legal, energy
5Companies · from Seville to Andorra
E2EProduct · from problem to deployment

Measured on real production systems

02 — Experience

Where I have worked

5 roles · 2019 → present

  1. Sep 2024 → Present· 2 years and 2 months

    Solutions Architect / Technical PM

    Andbank

    Andorra la Vella, Andorra

    Backend architecture and technical management in private banking: development standards, core-systems integration, and evaluation of AI solutions.

    • Design backend architecture (Java 21, Spring Boot 3) under Clean Architecture and hexagonal principles; new homebanking with 15+ components.
    • Lead the Spring Boot 2 → 3 migration (Jakarta namespace) and Tomcat 7/8 → 9/10 across 40+ VMs.
    • Integrate legacy systems (COBOL, AS400, DB2), evolve shipping-carrier integration APIs, and roll out Keycloak with MFA and per-jurisdiction rules.
    • Extend SonarQube across every repository, including analysis of 12,000+ COBOL files.
    • Rolled out Gemini Code Assist for the whole team as the department's first AI adoption.
    • Manage vendors technically, drive build-vs-buy decisions, and control technical debt on OpenShift (OCP4).
    Java 21Spring Boot 3OpenShiftKeycloakDB2COBOL/AS400SonarQube
  2. Mar 2022 → Sep 2024· 2 years and 7 months

    Senior Full Stack Engineer

    elAbogado

    Barcelona, Spain

    Full-stack development and platform modernization at Spain's leading legal marketplace.

    • Modernized legacy code: migrated Struts2 to React + Spring Boot.
    • Designed microservices and secure REST APIs.
    • Improved performance and maintainability, and evolved the architecture.
    • Managed content and landing pages with WordPress.
    JavaSpring BootReactMySQLREST APIsWordPress
  3. Jul 2021 → Apr 2022· 10 months

    Software Engineer

    Zemsania

    Madrid, Spain

    Backend microservices development for Vodafone.

    • Built microservices with Java and Spring Boot for distributed systems.
    • Designed and documented APIs with Swagger / OpenAPI.
    • Worked in a distributed team with Jira, Confluence and Slack.
    JavaSpring BootMicroservicesOpenAPIJira · Confluence
  4. Jul 2020 → Jul 2021· 1 year and 1 month

    Software Engineer (Java · Big Data)

    Keapps (Atos)

    Seville, Spain

    Kronos project (Endesa): enterprise Java systems and Big Data solutions.

    • Built Big Data solutions with Hadoop, Spark and Cassandra over energy-consumption data.
    • Optimized MapReduce jobs on HDFS/YARN and critical batch processes.
    JavaHadoopSparkCassandraHDFS · YARNSQL
  5. Aug 2019 → Apr 2020· 9 months

    Java & Big Data Developer

    Ayesa

    Seville, Spain

    Kronos project (Endesa): Java development and data pipelines.

    • Developed and maintained enterprise Java systems (SOAP, XML) with JSP and PrimeFaces interfaces.
    • Built large-scale data pipelines with MapReduce and S3 storage.
    JavaHadoopMapReduceS3JSP · PrimeFacesSOAP/XML
03 — Skills

Tools I use most

68 tools · 7 groups

Languages06
Java (8 → 21)TypeScriptJavaScriptGoPythonSQL
Backend & Architecture08
Spring Boot 3HibernateJPAREST / SOAPNode.jsFastAPIHexagonal ArchitectureMicroservices
Frontend07
ReactNext.jsTailwind CSSshadcn/uiBootstrapJSP · PrimeFacesWordPress
Data12
Oracle · PL/SQLDB2PostgreSQLMySQLSupabaseNeonRedis · UpstashBackblaze B2CassandraHadoop · HDFS · YARNSpark · MapReduceS3
Cloud & DevOps16
DockerKubernetesOpenShift (OCP4)VPS propio · DockerVercelGoogle Cloud RunCloud BuildGitHub ActionsBrevoTwilioServerlessJenkinsCI/CDKeycloakOAuth2Azure
AI & Automation12
Claude · Claude APIClaude CodeCodexChatGPTGeminiGemini Code AssistAntigravity IDEOrcaSDD · spec-kitMCP workflowsVercel AI SDKAI agents
Practice07
Spec-driven development for scoped product changesTyped contracts and validation at trust boundariesAutomated checks and deployment workflows where the product needs themVitest, strict TypeScript and production builds across my own projectsReference architecture designTechnical vendor managementScrum (SMPC certified)
04 — AI in product

Useful AI, bounded by engineering

Evidence · limits · fallback

  1. 01

    Closed source of truth

    This portfolio assistant receives a closed public dossier and is instructed to state when a detail is missing instead of filling the gap.

  2. 02

    Validated contracts

    AI inputs and outputs cross typed boundaries and runtime validation, including strict JSON contracts where structured extraction is used.

  3. 03

    Limits and fallback

    Rate limits and a global daily cap bound usage; important flows retain a manual path when AI is unavailable or uncertain.

  4. 04

    Deterministic where it matters

    Corte1D keeps optimization in a deterministic engine, while PRONOQ uses AI to explain results rather than decide predictions.

  5. 05

    AI behind automated gates

    SpecForge treats the AI as a supervised junior: it asks instead of inventing, its tests must fail before implementation and cannot be touched afterwards, every legacy source it cites is checked, and code only moves forward once it passes the tests, the gates and your review.

05 — Projects

Selected projects

8 projects · product · backend · AI

  • Other Tales

    In development · Private

    All-in-one platform for writers: Flutter app with offline writing and a Java 21 / Spring Boot 3.5 backend in hexagonal architecture, dockerized and migrating to a self-hosted VPS.

    Offline-first app: Riverpod, GoRouter and a local Drift/SQLite store with sync.

    FlutterRiverpodJava 21Spring Boot 3PostgreSQLDocker
    View details

  • Transolido

    Live · Publictransolido.com

    VERI*FACTU-compliant invoicing: a modular Java 21 / Spring Boot monolith with JWT authentication, Redis events on Upstash, PostgreSQL on Neon, a React frontend, and AI-assisted data extraction.

    VERI*FACTU regulatory compliance with full traceability.

    Java 21Spring Boot 3NeonUpstash RedisClaude APIVERI*FACTUCloud RunVercel
    View details

  • PRONOQ

    Live · Publicpronoq.jefmonjor.dev

    Football prediction pool with friends: mobile-first PWA for LaLiga and Champions with live scores, automatic standings and AI result analysis. In Spanish, English and Catalan.

    Live score tracking and automatic standings.

    Next.jsPostgreSQLPWADockerVPS propioES · EN · CA
    View details

  • Corte1D

    Live · Publiccorte1d.jefmonjor.dev

    Workshop SaaS: imports cut lists from Excel/CSV, optimizes 1D cutting with a deterministic engine and tracks stock. PWA with PDF export.

    Pure, deterministic cutting engine with canonical units.

    Next.jsNeonPWAExcelJSPDFKitBackblaze B2AI agents
    View details

  • Ilnami

    Live · Publicilnami.com

    Private gastronomy memory: log what you tried, where, and whether you'd go back. AI-powered OCR for instant capture, Mapbox maps and a Stripe-powered Plus tier.

    Supabase: Auth, PostgreSQL + PostGIS, Storage and RLS.

    Next.js 16SupabasePostGISStripeMapboxAI OCR
    View details

  • SpecForge

    Live · Publicgithub.com

    Go CLI that puts Claude Code or Gemini CLI on an assembly line that verifies every step: a spec interviewed and sealed, a reviewed plan, Red → Green → Refactor with your review and one commit per scenario. Version 5 adds verified legacy rewrites (Java 6 → 21) and ready-made Java, React, Python and Go projects.

    The AI asks instead of inventing: every agent answer ends with a JSON contract (done, question or blocked), and open questions reach the developer and are recorded.

    GoCobraHexagonal ArchitectureClaude CodeGemini CLIchromedpTDD · BDDLegacy → Java 21
    View details

  • Contact QR

    Live · Publiccontactqr.jefmonjor.dev

    Digital contact card: a QR code that adds your details (vCard) straight to the phone's contacts.

    Instant vCard via QR code.

    AstroQR · vCard
    View details
  • This portfolio01 / 03

    This portfolio

    Live · Publicjefmonjor.dev

    The site you are reading: a type-safe Next.js + tRPC + Zod stack with trilingual routing, an interactive terminal, a command palette, and a PDF CV generated from the same profile data.

    Type-safe Next.js + tRPC + Zod stack with English, Spanish and Catalan routing.

    Next.jsTypeScripttRPCZodTailwind CSSshadcn/uinext-intlMotion
    View details
Infra · Where I deploy
Self-hosted VPS · netcupDocker + GitHub Actions on my own server. PRONOQ in production (web + worker) and Other Tales migrating from Cloud Run.
VercelIlnami, the Transolido frontend and this portfolio — with automatic previews on every PR.
Google CloudCloud Run + Cloud Build for the Transolido backend, with a staging environment and automated health checks.

Services · Supabase · Neon · Upstash Redis · Backblaze B2 · Brevo · Stripe · Sentry

06 — Education & Languages

Education and languages

  1. 01

    Scrum Master Professional Certified (SMPC)

    SCRUMstudy

    2023

  2. 02

    Software Engineering (coursework)

    Universidad de Sevilla

    2014 — 2018

Languages
  • SpanishNative
  • EnglishB1 · professional
07 — Contact

The fastest way to reach me

Selectively open to relevant opportunities

Email
•••••••@•••••••

Project, role, or question: send a short message with the context and I will reply within two business days.

Send emailOpen LinkedIn
Based in
Andorra la Vella, Andorra
Status
Selectively open to relevant opportunitiesAndorra · Spain · Remote across European time zones
Timezone
CET / CEST
Jefferson Montesdeoca/Product Engineer focused on AI & backend
Designed and built from scratch · Next.js/Last updated · 2026-10-04