Who is SebasTZ: The Systems Engineer Behind Small Business Software

Behind every system that helps a business grow is a person who understood the real-world problem before writing a single line of code. That is the philosophy I build software with.

I'm Juan Sebastian Trujillo Zevallos, Systems Engineer graduated from Universidad Nacional Hermilio Valdizán in Huánuco, Peru. I build practical software for real businesses: car washes, beauty salons, billiard halls, and companies that need to digitalize their operations without friction.

Why I Started Building Software for Small Businesses

Throughout my engineering training and work in both public and private sectors, I consistently noticed the same pattern: businesses managing operations using paper notebooks, unorganized Excel spreadsheets, or pure memory. Not due to a lack of effort, but because available market solutions were overpriced, overly complex, or simply not built for their daily realities.

That is how the idea was born: build accessible, high-performance software focused on real operational results, with flexible options that don't choke business cash flows.

Products & Solutions I've Engineered

GlowApp — Beauty Salon & Spa Management

A full-stack SaaS platform built with Laravel, Vue 3, and Inertia.js. It solves the chaos of booking appointments over WhatsApp: smart calendar, automated schedule conflict validation, staff commission tracking, real-time KPI dashboards, and public booking APIs.

KoFin — Personal Finance Platform

A Web SaaS platform for personal financial tracking, engineered using Spring Boot, React, and TypeScript. Features transaction logging, visual savings goal tracking, customized analytics, and Excel/PDF data export with JWT authentication.

BilliardPOS — Pool & Billiards Hall Management

Specialized management software for pool halls and snooker rooms. Automates time-based table billing, manages bar/snooker tab orders per table, displays live table statuses, and generates shift financial reports. Built with Laravel, Livewire, and PostgreSQL.

Carwash POS — Car Wash & Auto Detailing POS

A point-of-sale and management system engineered specifically for car washes and auto detailing centers. Logs service tiers, calculates washer commissions, monitors product inventory, and produces daily sales reconciliations.

My Engineering Tech Stack

I don't use a single stack for everything; I select the right tool based on performance, scalability, and maintainability:

Frontend:

• React & Next.js for high-performance web applications

• Vue 3 with Inertia.js for seamless single-page application SaaS interfaces

• Tailwind CSS for modern, responsive UI design

Backend:

• Laravel for robust, structured web platforms

• Spring Boot for enterprise-grade Java REST APIs

• NestJS for scalable Node.js microservices

Data & Analytics:

• PostgreSQL & MySQL for core relational databases

• Python for data processing, cleaning, and predictive modeling

• Power BI for executive dashboards and visual business analytics

Core Principles

• One-Time Purchase & Lifetime Options: Clear pricing with no forced monthly lock-ins.

• Included Training: Hands-on onboarding for staff to ensure immediate operational efficiency.

• Direct Technical Support: Real support directly from the developer via WhatsApp & Email.

• Modern & Maintainable Architecture: Built with modern, battle-tested technology standards.

Get in Touch

If you run a business and want to discover how software can streamline your operations, let's talk.

Feel free to write to me directly on WhatsApp at +51 933317879 or via email at SebasTZcontacto@gmail.com.