Disney+ crashed on launch day as 10 million sign-ups outgrew its architecture

On Disney+'s first day, November 12, 2019, its initial 10 million subscribers were hit with a series of outages. The company attributed the failures to high demand and the way engineers had 'architected the app' — an admission that the platform's design, not third parties, was the problem.

Confidence going in was high. Michael Paull, head of Disney Streaming Services, had told The Verge in August that years of handling big streams — Game of Thrones premieres and finales — prepared the team for a launch of this size. It didn't. New subscribers couldn't log in, and those who got in found streaming nearly impossible. When rumours blamed Amazon or third-party platforms, Kevin Mayer, head of Disney's direct-to-consumer division, shut them down: 'It had to do with the way we architected the app... It was not Amazon.'

Disney+ ran on BAMTech technology — the platform that powered MLB's digital services and saved HBO Now's launch — but Mayer said BAMTech had never seen the traffic Disney+ brought in: 'We've never had demand like we saw that day and what we're continuing to see... There were some limits to the architecture that we had in place [that] were made apparent to us that weren't before.' A coding issue also broke where movies resumed in continue-watching; fixes were promised within weeks.

Launch-day outages across the service: users couldn't log in, streaming was nearly impossible, and the continue-watching feature broke.

The team sized its confidence to BAMTech's biggest previous streams, not to a day when millions would sign up and stream at once.

10 million day-one subscribers was a traffic profile no one at BAMTech had ever served, and the architecture's limits only became apparent under it.

Blaming outside platforms was ruled out early — Mayer publicly confirmed the fault was internal app architecture.

A separate coding defect in continue-watching showed the client software also wasn't ready for its first real audience.

Past peak-load wins don't certify an architecture for the next order of magnitude: a record launch has to be load-tested at record scale, not at the last record.

Client updates to fix the app, including the continue-watching defect, were expected to roll out within weeks. Mayer acknowledged Disney was new to this ballgame — 'having now gone through this launch, I see how difficult it is' — and said he hoped within a couple of years Disney+ would be 'knocking on that door' of Netflix, which served 160 million customers with very few outage problems.