# How On-Device AI Models Find Your Best Tinder Profile Photos

[Tinder](https://yomu.fyi/company/tinder) · Tinder · Apr 28, 2025

**Type:** Problem & solution

## Summary

Tinder developed an on-device AI Photo Selector to recommend compelling profile photos directly from a user's camera roll without exposing private assets. To establish a reference face, the system extracts facial landmarks via Apple's Vision framework and normalizes the crop using affine transformations. To prevent funnel drop-offs from mandatory selfies, the architecture includes a fallback mechanism that detects a single recognizable face in existing profile photos. Processing workflows execute concurrently across thousands of local assets while downloading and initializing TensorFlow Lite models in parallel using Combine. A dedicated analytics queue synchronizes operation counts with DispatchGroup to ensure accurate metric capture before the global rollout.

## Context

Manually sifting through camera rolls to select profile photos is overwhelming for users, often resulting in minimal effort, unengaging profiles, and negative impacts on engagement metrics. Additionally, requiring users to capture a live selfie to establish a reference face created user hesitation and significant funnel drop-offs.

## Approach / What changed

Tinder built an on-device AI Photo Selector utilizing Apple's Vision framework, CoreML, TensorFlow Lite, and Combine. The system captures a reference face from a selfie or existing profile photos via BasePhotoInference, applies affine transformations for normalized face crops, concurrently scans device assets, and tracks privacy-safe performance metrics using a dedicated analytics queue.

## Takeaways

- Normalized face cropping applies affine transformations and a least squares solution (Ax = B) onto a 112x112 grid to reliably align facial landmarks regardless of image angle.
- The BasePhotoInference fallback reduces funnel drop-offs by scanning existing profile photos for a single recognizable face instead of requiring a live selfie.
- Linearizing analytics through a dedicated DispatchQueue and DispatchGroup ensures synchronized and accurate metric reporting during concurrent on-device asset processing.

**Tags:** [iOS](https://yomu.fyi/topic/ios), [Machine Learning](https://yomu.fyi/topic/machine-learning), [Performance](https://yomu.fyi/topic/performance), [Privacy](https://yomu.fyi/topic/privacy)

[Read original post](https://medium.com/tinder/how-on-device-ai-models-find-your-best-tinder-profile-photos-a3eb0addb897)