Live tutoring platform: 5K concurrent video sessions

The situation

• Two ex-teachers shipped a tutoring MVP in a Cursor weekend. They got lucky on TikTok and 14,000 students signed up in 9 days.
• The product worked beautifully for 1-on-1 sessions, until 80 simultaneous rooms ran on the same Node WebRTC server. Audio dropped, video froze, tutors lost trust within a single class.
• Worse, a London school district had agreed to a 3-week paid pilot covering 1,200 students at peak. If the platform died on day one of the pilot, the deal, and the runway, was gone.

What we did

• LiveKit Cloud integration with role-based room permissions
• Composite session recordings on Cloudflare Stream with parent replay links
• Tutor dashboard with one-click join and attendance
• School district workspace with bulk rostering and outcomes export
• Inngest pipeline for transcripts, attendance, parent summaries
• Chaos test suite, region failover verified under 6 seconds

The result

• The pilot converted into a 14-school multi-year contract within 6 weeks.
• Concurrent traffic now peaks at 3,800 participants on weeknight evenings with zero incidents. The founders raised a £900K seed round on the back of the school deal, citing the platform's reliability as the key signal investors wanted.