ASCAlejandro Saez CastellsSenior Backend & Smart Contract Engineer

About

Backend and smart contract engineering grounded in real-world systems.

I am a Backend & Smart Contract Engineer based in Valencia, Spain. I build production-oriented backend systems and Web3 integrations using Java/Spring Boot, TypeScript/Node.js, PostgreSQL, Keycloak, OpenAPI, Solidity/EVM, Foundry, and DeFi primitives.

Real-world systems thinking

Before moving deeper into backend and blockchain engineering, I worked for years in industrial automation, where reliability, actors, timing, failure modes, and operational constraints matter.

I now apply that same mindset to APIs, smart contracts, workflow systems, identity boundaries, and blockchain integrations: permissions, deadlines, state transitions, auditability, integrations, and failure paths.

Current technical focus

Systems where state, identity, and reliability are explicit.

Backend services with Java/Spring Boot, REST APIs, PostgreSQL, authentication, and CI/CD

Smart contracts with Solidity/EVM, Foundry, access control, state machines, and tokenized workflows

Web3 integrations involving wallets, contract interactions, APIs, and user-facing flows

Real-world workflow systems involving roles, permissions, deadlines, KPIs, and auditability

What I bring

Production engineering across multiple system layers.

Backend systems

Java/Spring Boot, REST APIs, authentication, PostgreSQL, OpenAPI, provider integrations, caching, and CI/CD for production-oriented services.

Smart contracts & Web3

Solidity/EVM, Foundry, wallet flows, contract integrations, DeFi primitives, tokenized workflows, and blockchain-backed state transitions.

Real-world workflow modeling

Operational processes translated into software systems with actors, permissions, deadlines, statuses, KPIs, certificates, and failure paths.

Reliability mindset

Industrial automation discipline applied to backend and smart contract architecture: safety, uptime, maintainability, edge cases, and operational constraints.

Engineering background

From industrial automation to production software.

Automation work across automotive and production environments shaped a practical approach to system boundaries, state transitions, operational safety, maintainability, and root-cause debugging.

2023 - Present

A3M Global Monitoring

Java Backend / Blockchain Developer

  • Developed scalable backend services with Java and Spring Boot, delivering secure REST APIs.
  • Implemented authentication and access-control patterns using Keycloak and documented APIs with OpenAPI/Swagger.
  • Built internal backend functionality including a translation API with provider integrations, caching, PostgreSQL statistics, and CI/CD workflows.
Recent project

AtlasOra

Full-Stack Developer

  • Contributed to a live vacation-rental marketplace focused on trusted listings, user verification, search experience, and guest/host interactions.
  • Implemented and improved KYC/user verification flows, marketplace search behavior, and Web2/Web3 integration points.
2022 - 2024

Defdone

Full-Stack & Web3 Developer

  • Built full-stack applications with React, Node.js, and TypeScript.
  • Implemented Web3 integrations, wallet flows, contract interactions, API layers, and Casper ecosystem tooling including Fondant.
2014 - 2023

Industrial automation: Ford, Gestamp, SEAT and others

Automation Engineer

  • Programmed and commissioned automated production systems across Europe under tight uptime and safety constraints.
  • Applied process modeling and root-cause analysis, transferable to designing robust on-chain and backend workflows.

Best-fit technical areas

Where this background creates the most value.

GitHub / public profile

Contribution rhythm

Education

Industrial Engineering

Automation & Industrial Electronics

Universidad Politecnica de Valencia

Languages

  • Spanish (Native)
  • English (Fluent)
  • German (Basic)