Mauricio S. Callahan · Software engineer

Welcome to
my portfolio.

Explore a player-built pricing tool and my experience in payments engineering.

01 / Selected project

A little clarity
in a player-run market.

Riven Market Pricing Tool

I built a full-stack pricing tool for Warframe’s player-run market. It compares live auction listings and validated bids to estimate a price range with a confidence rating.

  • React
  • TypeScript
  • TanStack Query
  • Python
  • Flask
Explore Riven Market

  1. Live auctions

    Start with current listings for the selected weapon.

  2. Comparable rolls

    Compare attributes, rerolls, and listing age.

  3. Validated bids

    Check bidding evidence and filter outlier asking prices.

  4. Price range

    Turn comparable market data into an estimated range.

  5. Confidence

    Show how much evidence supports the estimate.

02 / Industry experience

Building in payments.
Learning together.

JPMorgan Chase

Software Engineering Intern, Payments
Columbus, OH · June–August 2026

My contribution

I built a Spring Boot bulk ACH cancellation API so onboarding clients could cancel test transactions together, and designed a PostgreSQL workflow for atomic batch cancellation.

Read my JPMorgan experience
Three people standing in front of the JPMorgan Chase & Co. reception wall