Hi, I’m Eugene Ostanko. I build useful, reliable web products.

EdTech · Remote

Building educator-facing assignment, grading and analytics workflows for a large learning platform.

• Reduced assignment creation time from 18.4 to 11.9 minutes by redesigning the editor, adding templates and automatic saving; completion increased by 16% and abandoned drafts fell by 22%.
• Reduced severe WCAG violations from 28 to 5 and increased successful task completion for keyboard and screen-reader users from 72% to 96%.
• Reduced failed requests in assignment and grading flows from 1.80% to 0.62%, preventing approximately 150,000 errors across 12.7 million requests and reducing support enquiries by 19%.
• Reduced flaky editor tests from 9.8% to 2.9%, shortened release validation by 23 minutes and enabled 28% more frequent product updates.
• Reduced invalid analytics events from 7.4% to 1.6% with standardized data contracts and automated validation, cutting manual corrections by 43%.

CRM & Commerce · Remote

Developed merchant order-management and checkout workflows with an emphasis on speed, operational safety and reliability.

• Reduced median bulk-order processing time from 14.6 to 9.8 minutes, saving 4.8 minutes per operational session and increasing completion by 13%.
• Improved checkout responsiveness by reducing Interaction to Next Paint from 286 to 198 milliseconds; checkout abandonment decreased by 6.7% and completion for extension-based flows increased by 4.2%.
• Reduced the time needed to contain a problematic release from 46 to 19 minutes through staged rollouts and automatic rollback; affected merchants per incident fell by 68%.
• Reduced failed requests in order management from 1.24% to 0.54% during peak sales, preventing approximately 154,000 failed operations across 22 million requests and reducing support workload by 17%.

Composable commerce · Remote

Worked on storefront catalog, cart and shared UI capabilities for multi-market commerce experiences.

• Increased the share of users continuing through the catalog after initial load by 14% by reducing LCP from 4.1 to 2.8 seconds across 620,000 sessions.
• Reduced catalog data transferred during browsing from 1.90 MB to 1.18 MB, improving slower-network performance and lowering data-transfer costs by 24%.
• Reduced average shopping-cart operation time by 32% through better storefront and commerce API integration, decreasing abandoned sessions by 11%.
• Accelerated development of standard interfaces by 27%, reduced duplicate UI components from 74 to 29, increased shared-library adoption from 48% to 86% and cut visual inconsistencies by 61%.