Nick Rossi

I build and operate the Online Check-In (OLCI) platform end to end across a Flutter mobile app, a TypeScript and NestJS middleware layer, and a React web client, the system more than 1,800 Sport Clips franchise locations use to run their real-time customer lineups. My work centers on middleware architecture, mobile performance, and the CI/CD that ships all three clients. I was rated Exceeds Expectations across every category in my most recent review.

• Cut mobile app cold-start time by 76% (roughly 7.5s to 1.8s) with six client-side fixes and no backend changes. The largest was a viewport bug sending screen pixels instead of geographic degrees, which had been forcing the store API to scan thousands of locations on every launch.
• Diagnosed and resolved a production bug that left map pins untappable on the store locator, tracing nine distinct root causes spanning Flutter, native iOS, and native Android in a single, fully documented pull request.
• Re-architected stylist wait times from a single shared model into accurate per-client times, collapsing two endpoints into one consolidated API and fixing five follow-on regressions across web and mobile after launch.
• Drove a middleware-first refactor of stylist display logic across all three clients, extracting it into a shared library to eliminate long-standing platform inconsistencies.
• Led the Map Pin project end to end: fixed a high-visibility map-render flicker bug in production and shipped real-time, context-aware store status indicators (Closing Soon, Opens Soon, lineup full).
• Rebuilt the Azure DevOps pipelines around parallelism and change detection, cutting mobile build time 43% and release time 46%, and web and middleware runtime 31%, with no added infrastructure cost.
• Designed a feature-flagged store-name normalization service validated against the full 1,800+ store footprint, and authored the cross-cutting spec and 25 user stories for a new Twilio-based notification capability.
• One of the team's highest-volume contributors, with 70 merged pull requests and 92 peer reviews over six months.

Built and shipped Solidity smart contracts and Python tooling for Crypto Unicorns, a web3 game, and led its migration onto a purpose-built gaming chain.

• Led the migration of dozens of smart contracts from Polygon to Xai, an Arbitrum-based L3 chain designed for web3 games.
• Built a cross-chain asset bridge holding over $12M in total value locked. The migration drove a 90% increase in daily active users and over 900k transactions.
• Created Python-based deployment and scripting tooling that streamlined the contract development and release process.

Founding engineer at an early-stage blockchain developer-tools startup, building StealthTest, an end-to-end platform for spinning up and testing applications in virtual chain environments. The product was later acquired by Hashlock.

• Built the full-stack application on Node.js, Express, and React, backed by microservices on GCP.
• Built a Next.js dashboard for managing Kubernetes-based virtual chain environments, and owned deployment and hosting end to end.
• Developed and deployed Solidity smart contracts on EVM chains as in-platform demo applications.

Full-stack engineer on the Node.js and React microservices behind att.com, serving millions of users daily on an agile team distributed across time zones.

• Shipped features across the wireless buyflow, product catalog, and marketing pages, the highest-traffic surfaces of att.com.
• Built the California Consumer Privacy Act (CCPA) compliance portal, supporting a legally mandated customer privacy workflow.

Summer C# development on defense GPS and cryptographic-key projects with a focus on security hardening.

• Wrote C# for GPS and crypto-key systems with an emphasis on security hardening. Held a Secret-level clearance.