Most freelancers deliver files. I deliver results.

You are here because something in your business is broken — maybe you are tracking sales on paper, maybe your website looks like it was built in 2015, maybe you are paying $200/month for software that a single spreadsheet could replace. I fix that.

WHO I AM:
I am the founder of GTS (Gontijo Technology Science) and the creator of business systems used by companies who refuse to waste money on overpriced software. I have built spreadsheet engines with over 37,000 formulas and zero errors. I have designed websites that load in under 2 seconds and convert visitors into buyers. I do not guess — I build, I test, I deliver.

WHAT I DO BETTER THAN ANYONE:

Advanced Spreadsheet Systems — I do not make "nice spreadsheets." I build complete business operating systems inside Excel and Google Sheets. Sales tracking, inventory with automatic alerts, financial dashboards with real-time P&L, client CRM, invoicing, cash flow forecasting, break-even analysis — all connected, all automated, all in one file. My flagship system has 22 integrated modules and 3 dynamic dashboards. Clients open it and their entire business is running.

Websites and Online Stores That Convert — I build modern, fast, mobile-first websites and Shopify stores designed to do one thing: make you money. Clean design, smooth checkout, optimized for every screen. No bloated templates, no slow pages, no amateur hour. Every site I deliver looks like it belongs to a company 10x your size.

WHAT MAKES ME DIFFERENT:

I test every formula before delivery — 37,000 of them, one by one. I do not use generic templates. Everything is custom-built for your business. I respond within 2 hours and deliver on deadline, every single time. I include 7 days of free support after every project. I speak business, not just code. I understand margins, cash flow, and ROI because I build the tools that track them.

MY SERVICES:
- Complete business management systems in Excel and Google Sheets
- Financial dashboards with automated KPIs and reporting
- Inventory tracking with low-stock alerts and reorder points
- Shopify store creation, setup, and customization
- WordPress and WooCommerce development
- High-converting landing pages and sales pages
- Data visualization and business intelligence tools
- Custom automation and workflow optimization

PROOF:
My live portfolio is at chdatatools.com — real products, real systems, built and running in production. I also publish on Amazon KDP with the Words of Joy Puzzle Books series, proving I can create, ship, and sell digital products at scale.

THE NEXT STEP:
Tell me what your business needs. I will reply within 2 hours with a clear plan, a realistic timeline, and a fair price. No fluff, no upsells, no surprises — just the solution you have been looking for.