EduSpark LMS – Video Streaming Glitch & Quiz Scoring Debug
Debugged asynchronous grading engine & eliminated video buffering glitches on LMS
Visit live project →ClientEduSpark Learning Systems
IndustryEducation & eLearning
Year2026
Duration2 weeks
Challenge & Solution
The Challenge
Students encountered freezing video lectures on iOS browsers and intermittent grading calculation errors upon quiz submission.
Our Solution
Fixed HLS video buffer headers, resolved asynchronous state race conditions in the grading engine, and deployed automated regression tests.
Bug Fixing Details
SeverityHigh
Issues fixed6
Time to resolveFixed in 24 hours
Issue types
Root cause
Race conditions in client-side Web Workers corrupted quiz scoring state, while misconfigured video stream CORS headers stalled playback.
Fix steps
- Debugged Web Worker thread synchronization and replaced mutable states with Redux store
- Reconfigured Cloudflare CDN caching and HLS video streaming buffer chunks
- Patched asynchronous scoring payload validation endpoints on the backend
- Added comprehensive automated Cypress regression testing suites
Our Process
1
Bug Triage
Captured network trace logs across diverse mobile devices and OS versions
2
HLS Stream Audit
Corrected MIME types and CDN edge caching headers
3
State Management Fix
Refactored quiz answer submission event loop
4
Automated QA
Deployed end-to-end regression tests to prevent future regressions
Results
100%Flawless quiz scoring accuracy
0Video buffering complaints reported
99.98%LMS platform uptime
Tools & Technologies
“Our student support tickets dropped to zero within 48 hours of deploying these fixes. Highly recommended debugging experts!”Rachel Nguyen, Director of Operations - EduSpark