MISSION_LOG — J. TORGBE-COFIEpayload dossier · filed from the archive · return for other payloads

● DOSSIER 03 — OPENED

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PAYLOAD 03 — FERNHEALTH → REALIZEDCARE → XRHEALTH · HEALTHFILED DIGITAL THERAPEUTIC · CHRONIC PAIN

FernHealth

ROLE: SENIOR FRONTEND ENGINEERCLASS: DIGITAL THERAPEUTICSTATUS: UNIFIED → NOW PART OF XRHEALTH

React Native migration unifying iOS, Android and web for a chronic-pain digital therapeutic — one codebase, three platforms, wearable integration, and personalized care plans. The product has since evolved into what is now XRHealth.

MISSION OBJECTIVE — why this payload flew

FernHealth was running separate native codebases for iOS and Android — duplicated features, duplicated bugs, and release cycles that had to be coordinated across two teams. The product was a digital therapeutic for chronic pain, built in partnership with pain physicians at Massachusetts General Hospital. The tech stack was getting in the way of the mission.

I was brought in to unify the codebase to React Native. That meant more than just rewriting screens — it meant rethinking the architecture, prepping docs for code structure and onboarding, integrating custom SSO for WebMD, and building the onboarding flow from scratch. I built wearable integration features that pulled activity data from Fitbit, feeding it into personalized care plans for members. I also set up LaunchDarkly for feature flags so we could roll out changes safely instead of big-bang releases. Along the way, I mentored two junior engineers through their first production deployments. Like teaching someone to find their first object through an eyepiece — you don't hand them the coordinates, you show them how to look.

One codebase, three platforms, one team that ships.

telemetry — counters, no invented KPIs

3PLATFORMS UNIFIED ios · android · web

8WEEK COACHED PROGRAM structured path to better outcomes

1CODEBASE down from two native codebases

2JUNIOR ENGINEERS MENTORED through first production deployments

SYSTEMS BREAKDOWN — what I built, module by module

SYS.01 – 06

SYS.01Unified React Native codebaseThe core migration — taking two separate native codebases and unifying them into a single React Native app. Shared components, shared navigation, shared state. One codebase that ships to iOS, Android, and web. Like multi-wavelength astronomy, which combines radio, optical, and infrared into a single view — one frame, one truth.FOUNDATION

SYS.02Onboarding flowBuilt the onboarding experience from scratch — guiding new users through account setup, initial assessment, and program placement. First light: the moment a new user sees the product clearly for the first time. First impressions matter, especially for people in pain.JOURNEY

SYS.03Custom SSO integrationIntegrated WebMD SSO so employees could sign in with their existing credentials. Fewer passwords, fewer barriers to getting help.ACCESS

SYS.04Coached program deliveryThe 8-week program is the heart of the product — daily content, exercises, and check-ins delivered through Contentful. Like a structured observation campaign: a defined period, daily check-ins, building toward a clear result. Structured so users can follow along without stopping their daily lives.CONTENT

SYS.05Feature flags & safe rolloutsLaunchDarkly integration for phased rollouts and A/B testing. Like observation planning — what to roll out, when, and to whom. No more big-bang releases: features ship to a subset of users, get validated, then roll out fully.CONTROL

SYS.06Wearable integration (Fitbit)Built features to track member activity via Fitbit, pulling health data into the platform. Activity data fed into personalized care plans, giving coaches and members a fuller picture of progress. Like photometry — measuring the light to understand the source.DATA

instrument rack — carried on this flight

React Nativecross-platform airframe

AWS Cognitoauth

AWS DynamoDBdata

AWS AppSync · GraphQLapi layer

AWS Kinesisdata streams

Contentfulcontent delivery

LaunchDarklyfeature flags

Fitbit APIwearable data