Juan Pablo Castro

Castro Solutions

Freelance Software Engineer & Architect

Spain in remote

• • Freelance backend engineering and software architecture on AWS and TypeScript — from greenfield system design to hardening existing platforms.
• • Cloud-native architecture: ECS Fargate, SQS, API Gateway, Cognito, RDS, Terraform IaC and CI/CD — designed with reliability, security and observability baked in.
• • Hands-on delivery for migrations, refactors and platform improvements — pairing strategic decisions with code-level execution.
• • AI engineering as part of the workflow: spec-driven workflows and agentic harness design for teams that want to accelerate delivery with code agents.

TypeScript NestJS Node.js AWS Terraform PostgreSQL Docker Claude Code

Capgemini

Tech Lead & Software Architect

Valencia, Spain (Remote)

• • Assigned to the Digital Lab of PostNL (a leading postal and delivery company in the Netherlands), turning prototypes into highly scalable products.
• • Owned the high-level architecture and implementation for a checkout acceleration solution across major e-commerce platforms and payment providers.
• • Engaged directly with client stakeholders to align technical decisions with business needs. Led a team of 5: mentoring, roadmap, prioritization and quality gates.
• • Drove Terraform IaC, Azure DevOps CI/CD, AWS autoscaling and queue-based workflows; ensured end-to-end traceability, reliability, security and observability.
• • Hosted architecture talks as part of Capgemini's Architects department.

Terraform (AWS) Azure DevOps Docker NestJS Prisma ORM Next.js React Angular

Tecon (Ekiba)

Full-Stack Developer

Parque Industrial del Elche, Alicante, Spain

• • Full-stack design and development from scratch of GICA, the wildfire response management system for GEACAM (regional government of Castilla-La Mancha).
• • Built the back-office to manage extinction units, shift changes and approvals, and to generate the daily reports (worked hours, mileage, overtime) feeding payroll and operations.
• • Led requirements gathering and system design directly with the client.

Angular 2+ NestJS Express Node GitLab PLESK Bash Linux

Cognizant

Programmer Analyst / Software Developer

Parque Tecnológico de Boecillo, Valladolid, Spain

• • Functional analysis and development of web applications with a strong client focus.
• • Used modern DevOps practices with continuous integration, following the Scrum framework.

Angular 2+ TypeScript RxJS HTML5 SCSS Jasmine Spring (Java) Git Bitbucket JIRA

Cognizant

Junior Full-Stack Developer

Parque Tecnológico de Boecillo, Valladolid, Spain

• • Development and maintenance of web components (logic and styling) used across projects.
• • Unit testing with Karma and Jasmine.
• • Development of Python microservices with scikit-learn to make predictions.
• • Kanban methodology.

Angular 2+ JavaScript RxJS HTML5 SCSS Karma-Jasmine Spring (Java) Git Bitbucket JIRA

Salamanca, Spain

• • Study and integration of agile frameworks with the CMMI (Capability Maturity Model Integration) quality standard.
• • Development of internal web applications for Google Assistant using DialogFlow (NLP) through JavaScript.
• • Publication of articles on the ViewNEXT / USAL blog.
• • Collaboration in introductory workshops on agile frameworks.

Angular 2+ JavaScript RxJS HTML5 SCSS Karma-Jasmine Spring (Java) Git Bitbucket JIRA