Why hire me
Ruben Isaac Lopez Peña
FullStack Software EngineerJavaReactNodeIAM
Building secure, event-driven systems that scale to millions.

Principal Engineer
Biography
I am a Principal Fullstack Engineer with Technical Lead capabilities—over 10+ years designing and delivering secure, high-scale systems end to end. I move comfortably across the stack, balancing JVM and service-oriented work in Java and Node.js with product-grade interfaces in React and TypeScript, keeping architecture, performance, and operability aligned.
In identity and access management, I have shipped OIDC-backed integrations and large-scale migrations—systems trusted at 40M+ Users scale—while favoring Clean Architecture, explicit domain boundaries, and implementations that can evolve when requirements or scale shift.
Leadership, for me, is hands-on: mentoring engineers, raising the bar on code review and design, and streamlining delivery by pairing strong engineering discipline with AI-assisted workflows (Cursor, Claude) so teams ship faster without cutting corners on quality or security.
Impact at a glance
40M+ Users
Large-scale migrations using Spring Batch.
40+ Clients
Successfully delivered IAM (OIDC/SAML) solutions.
30% Performance Gain
API optimization using Node.js / NestJS.
10+ Years
Full SDLC leadership from design to deployment.
Professional experience
Detailed roles with Technical Lead delivery, key contributions, and stack depth—expand each position for the full picture.
Trusted by Enterprise Partners
Platforms, cloud, and regulated sectors where I have delivered identity programs and full-stack systems at enterprise scale.
- Auth0Platform
- OktaPlatform
- AWSPlatform
- FintechSector
- Digital BankingSector
IAM & federation depth
Representative patterns from enterprise identity work — data-backed domain model, ready to plug into a real backend.
- OIDC
Enterprise OIDC Federation
Authorization Code + PKCE flows with enterprise IdP trust boundaries.
- SAML
SAML SSO Bridges
SP-initiated SSO with attribute mapping and session hardening.
- SCIM
SCIM User Lifecycle
Automated provisioning/deprovisioning aligned with HR and security policies.