Stranger Things × Doritos: How LiveKit and Casper Studios Powered an Interactive Telethon for 400,000 Fans
When Netflix and Doritos set out to promote the final season of Stranger Things, they envisioned an experience where fans could step directly into the world of the show. The vision was a fully interactive experience that felt authentic to the show's '80s roots, an old-school telethon where fans could call a phone number, leave messages of hope for the town of Hawkins, and interact with iconic voices from the era.
The hybrid voice solution
The experience begins with a call to the number printed on a "special-edition" Doritos bag, opening the door to an interactive adventure in Hawkins. On the other end, AI-powered agents bring '80s icons like David Hasselhoff, Paula Abdul, and ALF to life, guiding callers through a playful, choose-your-own-adventure conversation.
A look at the special edition Doritos bags.
Under the hood, the system blends voice AI with controlled creative guardrails. While the initial concept explored fully generative dialogue, the creators of Stranger Things, the Duffer Brothers, wanted a more human touch. The result is a hybrid approach where an LLM interprets what callers say and intelligently routes the conversation. Then, responses are served from a robust library of pre-recorded celebrity voiceovers that are processed and "de-aged".
Why Casper Studios chose LiveKit
Casper evaluated multiple approaches, including more traditional telephony stacks, but quickly ran into creative and technical limits.
For instance, a traditional IVR (Interactive Voice Response) system is an automated phone system that lets callers interact using keypad inputs or simple voice commands, usually to navigate menus or complete basic tasks. They usually follow a linear call flow like "press 1 for X, press 2 for Y".
In this case, each call in this experience needed to operate as a live session with its own state and progression, since there was no predefined script. The agent needed to track what a caller had already heard and dynamically decide what should happen next, similar to a game engine.
Using agents deployed on LiveKit Cloud, Casper built a multi-agent system where different agents could hand off control at key points in the conversation. LiveKit handled realtime audio transport, session management, and scaling, while the agents focused on interpreting speech, managing conversational state, and selecting the next audio response or story path.
"We were building something that could go from zero to hundreds of thousands of calls with almost no warning. Not having to manage infrastructure, scaling, or concurrency limits ourselves was huge. LiveKit Cloud made that possible."
Jay Singh, CEO and Founder of Casper Studios
LiveKit sits at the center of a broader voice stack, providing native SIP connectivity and integrating with providers like AssemblyAI for speech-to-text and ElevenLabs for voice processing. All of the realtime logic like the conversation state, routing decisions, and media orchestration runs on LiveKit.
"The brains of the experience live in LiveKit. That flexibility lets us evolve the creative logic late in the process, add new branches and behaviors, and still confidently handle traffic at scale."
Derek Gibbs, COO and Partner of Casper Studios
From concept to real impact
Even before the official campaign launch, the response was immediate. With minimal promotion, the hotline was already receiving thousands of calls per day, driven purely by organic discovery in stores.
Once deployed, with LiveKit Cloud powering the experience, Casper was able to handle hundreds of concurrent callers. Over the course of the campaign, including the teaser period and post-launch activity, the hotline received over 400,000 interactive call sessions running through LiveKit.
A blueprint for the future of voice-driven marketing campaigns
Omnicom and its creative partners are already exploring similar voice-first experiences for other major brands, anticipating growing demand in the years ahead.
As brands look for new ways to engage audiences, the Stranger Things × Doritos telethon campaign demonstrates what's possible when realtime voice, creative storytelling, and scalable infrastructure come together to deliver a memorable, interactive experience.