Braulio De Leon
Staff Frontend Engineer · Payments, Auth & Checkout · React · TypeScript
📍 Montevideo, Uruguay · Remote (US time zones)
15+ years building enterprise frontends for US companies, including American Express and Toyota. Most recently owned the frontend of 3D Secure card authentication for the Amex travel platform.
About Me
I'm a frontend engineer with 15+ years on enterprise platforms for US companies, including American Express and Toyota. Most recently I owned the frontend of 3D Secure card authentication for the Amex travel platform, which became the shared foundation for all three of its lines of business.
I work in React and TypeScript today, with a long Angular background. My focus is on the flows where mistakes are expensive: payments, authentication and checkout, shipped incrementally behind feature flags with safe rollback.
I was Head of Engineering at Arionkoder (hiring, team leads, internal tooling). Now I'm focused on hands-on, staff-level individual contributor work, building with AI agents as part of my daily workflow.
Skills
- Frontend
- React, Next.js, TypeScript, Angular, Nx monorepos, accessibility (a11y), i18n
- Payments & Auth
- 3D Secure, OAuth with mTLS, JWE, feature-flagged rollouts
- AI & Tooling
- Agentic development with Claude Code, PRD-driven agent workflows, Node.js, PostgreSQL / Supabase, Prisma, CI/CD
Experience
iSeatz, American Express Travel Platform
Apr 2024 – Oct 2026
Senior Frontend Engineer · via Arionkoder
React · Next.js · TypeScript · Nx monorepo · OAuth / mTLS · JWE · Contentful · Feature flags
- Owned the frontend of 3D Secure card authentication with American Express, a payments-compliance requirement for the Canadian market, delivered end to end with Amex, infrastructure and business analysts. It became the shared foundation for all three lines of business on the platform.
- Became the go-to engineer for Amex authentication issues across teams, and made the flow safe for every team to build and test against without weakening production compliance.
- Part of the Cars team, the first to ship to production on the re-engineered platform; then supported the other lines of business through their own production rollouts.
- Owned critical checkout flows in a high-traffic transactional product, shipping incrementally behind feature flags with safe rollback.
Arionkoder
Mar 2025 – Oct 2026
Head of Engineering · alongside client delivery
- Built Engineering Map from scratch, an internal staffing and assignment platform (Next.js, TypeScript, Prisma, AWS) that gave the engineering area visibility into who works where across teams and clients.
- Designed the frontend technical hiring process, used for about 50 candidates: assessment kits with seeded bugs scaled by seniority, a live conversational format, 1–4 rubrics and interviewer guides.
- Advised the product lead of Sokuvo, the company's AI delivery-layer product, on how an AI-agent software lifecycle works in practice.
Pariveda, Toyota Enterprise Platform
Oct 2021 – Apr 2024
Senior Frontend Engineer / Team Lead · via Arionkoder
Angular · TypeScript
- Stabilized a large, long-lived Angular codebase, bringing production error rates to an all-time low; recognized by product leadership as a key project success.
- Led frontend work in a distributed team across 4 time zones, setting the conventions, coding standards and review process the team adopted.
Overactive, XPO Logistics
Jan 2019 – Oct 2021
Senior Frontend Engineer
Angular · AG-Grid · Internal tooling
- Built data-intensive operations tools for the LTL freight business: pickup and delivery management and route optimization, with large data grids synced to a live map.
- Contributed to the shared design system used by multiple teams; reviews, documentation and mentoring of junior engineers.
Earlier: Full Stack Engineer at BROS (2017–2018) and EDU Editorial (2014–2016); independent developer (2009–2014).
Side project
Agent-driven development workflow
Next.js · Supabase / PostgreSQL · WhatsApp Business API · Claude Code
A small project to test an end-to-end AI-agent workflow on a real use case: I wrote the PRDs and architecture and reviewed the output; Claude Code agents implemented it. The result is a simple WhatsApp reminder system (confirm or reschedule) used by a local clinic.
github.com/bradelev/vaig-schedulingRecent Writing
Thoughts on software engineering, leadership, and technology
Building a Personal Brand with AI-Powered Automation: From One Prompt to Production
How I rebuilt my entire personal website in hours using Claude Code, with automated Jira project management, GitHub integration, and Vercel deployment—all from a single initial prompt.
Reflections on CES 2025: Innovation, Gaps, and Shared Responsibility
My observations from CES 2025 on technological innovation, market accessibility, labor reconversion, and the responsibility of both industry and emerging regions.
Teamwork Unlocks New Goals
A personal reflection on how shifting focus from individual achievement to team collaboration transformed both my cycling performance and professional mindset.
Let's Work Together
I'm looking for a staff-level, hands-on frontend role with a remote US team. If that sounds like your team, I'd like to hear from you.
Prefer the full picture? Download my CV (PDF).