marioaslau

• Improved React Native mobile application performance, reducing MetaMask Mobile cold startup time by 75% (20s → 5s) by profiling startup execution and resolving critical performance bottlenecks. • Led technical direction for the MetaMask Predictions Performance Initiative, owning the end-to-end performance audit, engineering priorities, system improvement roadmap, and coordination of 3 engineers in partnership with Product. • Built MetaMask Mobile’s application performance observability platform, instrumenting 6 critical user journeys with custom tracing and Sentry dashboards used across the Mobile organization; introduced PR-level regression detection to identify performance degradation before release and pinpoint the affected flow during debugging. • Led a cross-functional reliability engineering initiative that reduced Vault corruption and recovery issues by 50%, driving improvements across observability, persistence, migrations, and platform architecture. • Architected and delivered a custom file-system-based persistence layer,improving mobile state management and application performance and reducing warm startup time by approximately 5s on iOS and 10s on Android. • Consolidated 4 independent geolocation implementations into a shared controller powering Rewards, Ramp, Card, and Perps, eliminating 2–4 redundant geolocation API calls per app launch while centralising caching, error handling, and location configuration. • Delivered 3 core improvements to MetaMask Predictions: a new homepage entry point, reusable Bottom Sheet infrastructure, and Polymarket betting-flow enhancements, simplifying access to prediction markets and supporting increased prediction-market activity during major sporting events, including the 2025/26 UEFA Champions League. • Introduced AI-assisted engineering workflows across ticket scoping, implementation planning, coding, and PR review, sharing Cursor-based practices and structured context techniques with a 9-person engineering team. Increased my own weekly delivery throughput by approximately 3×, from 2–3 to 8–9 PRs on comparable work.

• Architected and delivered a reliable, scalable serverless AWS transactional email service powering order confirmations for 100% of online orders placed globally through LEGO.com, supporting peak volumes of 35 orders per second during major product launches. • Developed an enterprise React Native order-management application used by 2,000+ retail employees across 12+ countries, enabling assisted ecommerce purchases and converting an estimated 10–20% of out-of-stock enquiries into completed sales. • Built and shipped React.js ecommerce applications across LEGO.com, including its global footer, on a digital platform serving 250M+ visits annually. • Acted as Team Captain, owning the team’s delivery cadence, facilitating stand-ups and retrospectives, coordinating priorities between the Product Manager and Tech Lead, and removing delivery blockers; also led 3 cohorts of LEGO’s BrickCamp engineering bootcamp, supporting approximately 36 junior developers alongside 6 senior engineering speakers and mentors.

Developed and enhanced WalkUp’s Restaurant Management System, giving partner restaurants real-time visibility into table availability, customer queues, wait times, and turnover; combined with operational training, the platform helped partners achieve approximately 30% higher revenue through faster table utilisation and reduced idle capacity.