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SAIL
Healthcare practice
MGB

Engagement · Cadence

Cadence.

Hardened mobile data collection, high-speed ingestion, and an Auto-ML baseline. Production-grade infrastructure for behavioral signal at scale.

Sector Digital Health
Partner Mass General Brigham
First outcome Wk 4 · SDKs
MVP live Wk 13

The problem

Built to answer a paper. Not to run at scale.

The existing digital phenotyping stack was built in academic labs to answer a single paper. It buckles when you push past prototype. We aren't iterating on it. We're rebuilding underneath it.

What exists

Beiwe. Aware. RAPIDS. Open-source tools that grew up in academic labs to answer a paper, not run at scale. Brittle SDKs, lossy collection, no clean path from raw signal to a usable feature.

What production demands

Hardened mobile capture across iOS and Android. Lossless ingestion at scale. Features that modellers can actually work with. A provenance chain everyone in the loop will trust.

What this engagement does

A native-mobile, AI-native infrastructure for digital phenotyping. Built to a 13-week clock, with each milestone a working surface the team can run against.

The pipeline

Phone to feature. Four stages.

Native capture, lossless ingestion, modellable features, AutoML baseline. One pipeline. One source of truth. One handoff.

Fig · Pipeline · CadenceStreaming
Stage 01SDKsiOS · AndroidNative collection
Stage 02IngestPipelineHigh-speed cleansing
Stage 03FeaturesEngineeringBehavioral signals
Stage 04AutoMLBaselinePattern discovery
Signals/sec10k+
LosslessYes
Pilot-readyWk 13

Milestone deep dive

Four milestones. Each one a deploy.

M1 WK 01–04 Native mobile SDKs Hardened by default.

Swift and Kotlin SDKs written the idiomatic way, not auto-generated. Battery-aware sampling, lossless local buffering, structured retry. The collection layer survives airline mode, low-power mode, and OS upgrades.

Deliverables
Swift SDK · iOS Kotlin SDK · Android Sampling kernel Reference docs
M2 WK 05–07 Ingestion & cleansing High-speed by default.

Backend pipeline tuned for thousands of signals per second per participant. Schema-enforced at ingest. Cleansing rules versioned with the spec. Throughput tested at full-cohort scale before sign-off.

Deliverables
Ingestion service Schema registry Cleansing pipeline Throughput tests
M3 WK 08–10 Features & demo Modellable by default.

Feature engineering pipeline that turns raw signal into the columns the modellers actually want. Flutter demo app for live participant inspection. Operations dashboard an operator can run unattended.

Deliverables
Feature pipeline Flutter demo app Operations dashboard Sample features
M4 WK 11–13 AutoML & validation Production-ready by default.

Auto-ML baseline that flags initial behavioral patterns in the sample. End-to-end test of the full pipeline. Documentation the team uses to operate the platform without us in the room.

Deliverables
AutoML baseline End-to-end tests Operator runbook Handoff package

Timeline

Thirteen weeks. No detours.

Fig · 04MVP milestonesRev 1.0 — 2026·Q1
WK 04live
SDKs live
iOS · Android
WK 07
Ingestion engine
lossless · governed
WK 10
Features + demo
participant-ready
WK 13
Production-ready
AutoML · handoff
Drafted in-labMGB · CADENCE · 001

Foundations

Why this, and why now.

I.

The instrument.
Built for the load.

Digital phenotyping is the next instrument for measuring how people actually behave. The signal is rich, but the existing tools were never built for the load. The platform dies on infrastructure, not on the science.

II.

The moment.
Sensors finally arrived.

Sensor coverage on consumer phones is finally high enough to drive real pattern discovery. The bottleneck is no longer the device — it's the pipeline between the device and the modeller.