John Engleman

I’m a senior software engineer who specializes in high-volume API integrations and distributed web platforms. I’ve delivered production integrations at high velocity (1–3/week) across partner ecosystems in remote, asynchronous teams supporting millions of users.

At NerdWallet, I’ve onboarded 30+ external partners by implementing Ping-Post and Multimatch routing integrations to ensure reliable lead delivery and maximize conversion revenue. I also built a CDK-managed AWS secrets service with lazy loading and short-TTL Redis caching, then migrated 100+ partner API secrets off Vercel after hitting its storage cap.

I focus on correctness and security while moving fast: I translate complex external API schemas into strict TypeScript definitions with runtime validation using Zod, and I’ve implemented secure data transmission workflows using JWT/JWE and mTLS for sensitive PII. I also architected and delivered a partner embeddable widget platform in ~8 weeks, including a lightweight script loader, runtime styling configuration, and cross-domain data fetching.

As a solo founder, I recently shipped a native-integrated React Native/Swift iOS app to the App Store end to end, including Apple Screen Time enforcement, system shields, widgets, Live Activities, and on-device photo-proof verification (Vision/VisionKit). I engineered an offline-first persistence layer and backend services using Cloudflare Workers and RevenueCat webhook processing, then AI-accelerated development with Claude/Cursor while verifying all AI-generated implementation.