Cristoval Martinez
Enterprise Payments & Software Architecture
I'm a full-stack software engineer and Stripe expert who helps businesses design, build, and scale the systems that move money. From custom SaaS billing platforms to API integrations and cloud infrastructure — I build the backend that keeps revenue flowing.
Featured Work
Healthcare AI · SaaS
Remexis
Turned a Single-User Tool into a Revenue-Generating SaaS
Remexis had the product — but no payment infrastructure to monetize it at scale. We built the billing system that let them go from one user to multi-tenant enterprise contracts.
Before this project, Remexis had no way to charge organizations, manage seats, or track AI usage per team. We built their entire payment presence from scratch: a branded billing experience, tiered pricing, automated invoicing, and a Stripe webhook pipeline that keeps everything in sync — so the business runs without manual intervention.
Key Outcomes
- Unlocked B2B revenue with seat-based billing
- Self-service upgrade & downgrade for clients
- Automated invoicing removes manual follow-up
- Audit-ready billing dashboard for compliance
SaaS · Construction
UpmarkPDF
Built the Payment System That Launched Their Web Presence
UpmarkPDF needed a professional, scalable way to charge contractors online — across three tiers, with enterprise pricing. We built it all, from checkout to customer portal.
Fitness · Web & Payments
War House Gyms
Gave a Gym Chain an Online Payment Presence
War House Gyms had no way to collect payments or manage memberships online. We built the web system that put them in control — and let members self-serve without staff.
Currently helping businesses in the Central Valley & SF Bay Area scale their payment infrastructure and engineering teams.