Mark Park

Promoted to backend lead on the recommendation of senior architects and management; led a team of up to 5 engineers rebuilding a heavily criticized legacy client-facing platform from POC to MVP to production, serving 500–1,000 daily active users.

• Architected the platform's two core microservices along clear domain boundaries: a Drools-based rules engine governing all UI field behavior, and a secure persistence service acting as the sole authorized gateway to internal systems.
• Led the Java 17→21 migration ahead of the MVP release with minimal disruption to the delivery timeline.
• Sole backend engineer on-call during live-market hours, monitoring and maintaining services in real time while developing upcoming features.
• Automated over 60% of previously manual onboarding and KYC logic and improved responsiveness by 60–80% over the legacy platform.
• Built a generic recursive Cosmos DB save utility on the Patch API supporting arbitrary object structures at 5–10 ms response times, working around a known SDK limitation.
• Mentored a summer intern new to enterprise Java through shipping several production APIs.

Hand-picked by the lead architect to build a standalone Drools rules-engine microservice; cut processing time for 500+ business rules from several seconds to 50–100 ms using fact injection, agenda groups, and salience-based prioritization. Delivered the base architecture and MVP in 3 months before handoff; later extended to power a second production application.

Mentored by a 20-year architect on a 3-person team; became a primary contributor on core transaction-processing design across an 18-month POC-to-MVP build and 2 years of enhancements. Became the team's primary production maintainer, personally overseeing live market-hours processing of transactions worth tens of millions of dollars daily.

• Owned the end-to-end financial processing lifecycle for $10M+ in daily transactions ($106B+ lifetime): bank confirmations, OFAC compliance scans, and government audit-trail processing.
• Eliminated production deadlock failures — from 2–5 incidents per day to zero — via optimistic concurrency control, retryable services, and custom thread pool executors.
• Designed an event-driven architecture on Azure Event Grid powering 20+ heavy scheduled jobs, several on 5-minute cycles, including OFAC scanning and bank posting.
• Implemented SAGA choreography over RabbitMQ for cross-service transactions, later migrating messaging to Azure Service Bus.
• Assisted the team's Java 8→21 upgrade and drove post-MVP enhancements, including FIS Global Plus posting integration and Azure-based check-reading AI.
• Led technical design discussions across cross-functional groups of 20–30 with product owners and business analysts.