Ismael Julià Reifs

• ● Led the integration and customization of Stripe Radar fraud signals by collaborating with Stripe data science team, designing services that combined AI outputs, internal ML signals, rule-based logic, and historical context, exposing decisions via APIs for React payment flows, resulting in a 35% reduction in fraud after the first MVP and 80% after the full release.

• ● Redesigned payment failure UX in React/TypeScript, turning declines into actionable feedback for the user; collaborating across product, design, and support teams, reducing churn by 15% and escalation tickets by 20%.

• ● Designed and implemented a service-oriented microservice to integrate a recently acquired company as an expense provider, unifying platform configurations and exposing APIs for client-facing expense data; deployed via canary releases with cron alerts to detect misconfigurations and enable rapid response from the team, reducing possible escalations.

• ● Built an internal automation platform from scratch, empowering IT team to define and run workflow-driven data processes; developed by using Django, Flask APIs and Vue.js with robust contracts, retries, and auditability, reducing manual work by 60% from the team, and implemented SCIM-based identity and access management to onboard new employees.

• ● Integrated ML-driven fraud detection signals into live payment authorization flows under strict latency and accuracy constraints, collaborating closely with the data science team.

• ● Delivered new PSD2-compliant bank integrations from scratch, maintaining seamless user experience and reducing team workload by automating bank transactions.