Build new or move forward.

Production-grade software, engineered end to end — architecture, code, and delivery for new products and the systems already running.

Sergio Peña Bayona

From the database to the screen

I handle software at every layer — from modeling the data and background services to polishing the user interface, applying the same engineering standards to every step.

6+
Years engineering
100%
Remote delivery
8+
Production projects

From problem to solution

Production software shipped — from real-time IoT platforms to ERP systems, SaaS products, and client sites — across front end, back end, and the infrastructure between, adapting to whatever each project demanded.

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Landing page for a creative brand studio

Vrandalismo · Creative Studio · Freelance

Built the marketing site for Vrandalismo, a creative studio, with Astro for fast static delivery and Tailwind for a tightly controlled design system. Wired up Sanity CMS so the team can edit services and case studies on their own, no developer in the loop.

AstroTailwind CSSSanity CMS

How I view development

P.01

The problem drives the tool

I choose technology based on project requirements, not personal hype. Languages and frameworks are tools: I adapt to whatever is needed to be productive from day one.

P.02

Code you can prove

Tests and CI aren't an afterthought for the end of the project; they are my safety net to iterate fast and without fear. If breaking things in production has a real cost, testing is mandatory.

P.03

Write for the next maintainer

I optimize code so the team inheriting it can understand it seamlessly, not to feel like the smartest developer in the room today. Clear contracts, clean architecture, and straightforward decisions.

Architecture and reliable integration of AI

AI changes how fast we write code, not the responsibility to do it right. The real value isn't in knowing how to write a prompt — it's in the software architecture that allows a model to interact with a complex codebase safely and predictably.

Skills

I package business logic and workflows into reusable skills. This ensures AI agents follow standardized processes instead of improvising on every run.

Harnesses

I design the runtime environment and boundaries around the model — including custom tools, validation layers, and sandboxing — to guarantee predictable, production-ready outputs, moving past toy demos.

Structured context

I write code and documentation optimized for LLM comprehension: strict typing, explicit contracts, and semantic architecture. Conveniently, what makes life easier for the model also makes it easier for your developers.