A learning platform that survives results day

1 The problem

Solstice served 240 institutions on a platform that fell over predictably twice a year: enrolment week and results day. In the previous year it had been unreachable for six hours while 40,000 students refreshed the same page. The architecture assumed steady traffic and had no caching layer worth the name.

2 Our approach

We rebuilt the read path around aggressive caching and pre-computed result sets, moved file delivery to a CDN, and separated the write-heavy examination engine onto its own infrastructure so a results surge could not starve everyday coursework. Then we load-tested to three times the worst historical peak, six weeks before the date.

3 What we built

• Multi-tenant architecture with per-institution data isolation
• Pre-computed result publication with cache warming ahead of release
• Examination engine on isolated infrastructure with its own autoscaling
• CDN delivery for all course media
• Queue-based grade processing with backpressure handling
• Load testing at 3× peak, run monthly thereafter

4 Technology