Designing an adaptable listening experience using biofeedback

Spotify Sync is a new feature that allows listeners to connect their wearable devices and unlock playlists that adapt in real time to match their mood and activities. Sync opens the door to a new way of discovering and curating audio, one that fits the many facets of you.


Exploring the future of audio discovery and curation

Listeners have come to trust and rely on Spotify's recommendation algorithm to serve up songs based on their listening history. But there remains a lag between Spotify's data-driven picture of a user and the user's changing preferences. It cannot yet adapt to changes in the moment.

There is also a recency bias in the content that Spotify suggests. This can limit exploration of new music and present options that do not match the listener’s current mood or activity level.

Our team explored ways to integrate new technology to provide better discovery experiences. The end result was Spotify Sync — a new feature that allows users to connect their wearable devices and access playlists that adapt to their activities in the moment.

I led the interaction design for this project, with a focus on the wearable device experience. It was my first experience designing across platforms and I enjoyed the challenge of developing intuitive interaction patterns for multiple devices.


There is often a gap between Spotify’s suggested playlists and what listeners are seeking in the moment.

User focus groups and secondary research showed that people are using Spotify for large portions of their day. During that time, they are constantly switching activities and adjusting the music to match the moment. The discovery feature often doesn’t adapt fast enough or present the right options, which leads to excessive scrolling and decision fatigue.

Thought Starter

How might we improve Spotify’s ability to understand the listener's context and intentions?

Target Audience

Adopters of wearable technology are primed to explore new features that personalize experiences.

Wearable technology is one of the fastest growing segments in consumer electronics.
Current shifts in the market have repositioned wearable technology as a tool for everyday life and health monitoring, rather a specialized use case for health and exercise aficionados.

It’s becoming easier and easier for people to track their health metrics. The next step is to integrate that data with other sensory inputs to create optimal experiences.


Spotify can leverage integrated technologies to create new feedback loops that improve the listening experience.

There is a rising demand for audio content and a growing preference of users for listening while multitasking during commutes, work, exercise, or household chores. Biometric data creates a new feedback loop which allows Spotify to understand context: when certain types of music are most appealing to the listener.

Introducing Spotify Sync

Spotify Sync allows users to connect their wearable devices and unlock playlists that adapt to their activities in the moment. This opens the door to discovering and curating new music that fits the many facets of you.

01. How it works

Users with wearable devices, such as an Apple Watch, are prompted to integrate Sync with health data.
A new persistent playlist appears on the home screen.
Users can choose and modify their activity state using their phone or wearable device.
Liking a song during an activity session tags it and creates a new filter in the Liked Songs playlist.
interactive wearable Prototype

Users can choose their intended activity using the phone or wearable. During a Sync session, the playlist modulates based on how the listener’s biometrics change over the course of the session.

Leveraging Spotify Audio Features

The app will use machine learning to cross-analyze the listener’s biofeedback and their reaction to audio choices based on the audio features tracked by Spotify. (Source) This creates a new feedback loop by which to generate insights about the user experience.

02. Biofeedback Deep Dive

The EKG sensor in the wearable device monitors the listener's biometrics. Spotify can then read that data and adjust the playlist selections based to keep listeners at their desired activity level. In this use case, the primary metric monitored will be heart rate variability.

Heart rate variability (HRV) measures the rate of change of the heart beat over time. Essentially, it indicates stress levels and the balance between an person's parasympathetic (relaxed) and sympathetic (fight-or-flight) nervous systems. It is a reliable, non-invasive biometric of stress. (Source)

activity States


STress: Low
Promotes recovery and mindfulness


STress: Moderate
Promotes awareness and focus


STress: High
Promotes adaptation and growth

Using the Taptic Engine on the Apple Watch, Spotify listeners can feel pulsing vibrations at the start of each Sync session.

Exposure to vibration has been shown to acutely affect people's heart rate variability. Sync takes advantage of Apple's Taptic Engine to deliver science-based vibration patterns at the start of a listening session. This feature helps Sync create a multi-sensory bridge to the chosen activity state. (Source)

03. Reflection and Sharing

sync with friends

Sync can be a tool for social connection

Sync offers a way to enhance connection between people on the app. Listener's can now see when a friend is in a Sync session and listen alongside them, deepening the social dimension of music discovery on the platform.

Sync Stats

Creating moments for reflection

By offering stats from Sync sessions on the profile screen, listeners can track their listening over time. This adds a reflective utility to the rarely-used profile page.

04. Data Privacy and Opting Out

Throughout this project, we recognized that data privacy is an important issue and a concern for many people, especially when it comes to biometric data. We established following guidelines for the use of Sync data to address some of the most pressing concerns.

  • All Sync health integrations are opt-in
  • Health data sourced from wearables and other devices will be read-only
  • Spotify will store no data after the sessions end (aside from songs liked during the activity)
Measuring Success

Exploring the intersection of business and design

Sync is not a shipped feature, so I do not have real-world outcomes to discuss. That said, we wanted to explore a few metrics against which Spotify might gauge the impact of this work.

Business objective

  • Increase conversion and retention rates for Spotify premium subscriptions

Potential performance metrics

  • Increased daily usage rates
  • Conversions to premium subscription by listeners using Sync
  • Number of users that opt in for Sync feature
  • Percentage of "Liked Song" interactions during Sync session
  • Time spent listening to friend Sync sessions


By integrating biometric data into its existing recommendation engine, Spotify can better adapt to listener needs, create a more personalized experience, and promote increased interaction on the platform. This deepens the relationship between the user’s daily life and the soundtrack provided by Spotify, ultimately supporting the business goal of increased customer conversion and retention rates.