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Customer stories

Customer story · AI · Mobile · Real-time fitness

25,000+ runners. $51K revenue. One platform that cheers, coaches, and scales.

CheerMy Run needed more than a tracking app—it needed live social energy on race day, AI that understands each athlete, and infrastructure that survives cheer storms at marathon scale. Intellixa Labs delivered the full stack: RAG-powered training and nutrition plans from real user data, sub-second GPS fan-out, bilingual voice AI, and subscription monetization that turned engagement into revenue.

Business and engineering outcomes Intellixa delivered

  • 25K+

    active users on a production Flutter + Node.js platform built for daily retention

  • $51K

    USD subscription revenue verified in production MongoDB—not a marketing estimate

  • RAG AI

    personalized exercise and diet plans grounded in each runner’s profile, goals, and activity history

  • Sub-second

    live GPS and spectator updates via Redis, Socket.IO, and SSE at race-time concurrency

Platform capabilities

RAG · LLM · vector retrieval

RAG Fitness Intelligence

Retrieval-augmented pipelines ingest onboarding data, race history, devices, and goals—then generate customized workout and meal plans, not generic templates.

Redis · Socket.IO · SSE

Live Race Engine

Redis hot path, Socket.IO rooms, and public SSE streams so spectators cheer without installing the app—while MongoDB syncs durable state on cadence.

Polly · Bull · FCM · ffmpeg

Voice & Cheer AI

AWS Polly neural TTS (EN/ES), intelligent Bull queues, ffmpeg audio merge, and on-device TTS fallback—fair delivery when dozens cheer at once.

The problem: isolated runners, generic fitness apps, and fragile live systems

CheerMy Run’s founders faced three blockers at once. Runners wanted friends on the course virtually—live maps, voice cheers, zero friction for spectators—but off-the-shelf fitness apps only offered post-run stats, not in-the-moment support. Second, users expected personalized coaching: training blocks and diet guidance that reflect their experience level, gear, distance goals, and real activity data—not one-size-fits-all PDFs. Third, any live GPS + push audio system would collapse under cheer storms, bilingual audiences, and high-frequency location writes without a purpose-built backend.

How Intellixa Labs handled it end-to-end

Intellixa architected and shipped the production platform: a Node.js API with Redis-first race telemetry, Socket.IO and SSE for viral spectator growth, and a RAG layer that retrieves each athlete’s structured profile and history before LLM generation of exercise and nutrition plans. We integrated AWS Polly for race-day voice, Bull queues for spaced cheer delivery, route optimization and S3 exports after finish, Strava for ecosystem reach, and Google Play / Apple IAP plus Superwall webhooks for monetization—scaling to 25,000+ users and $51,000 USD in revenue without sacrificing latency or UX.

Intellixa did not bolt AI onto a CRUD app—we wired retrieval, real-time infrastructure, and revenue systems into one cohesive product loop: personalize → run live → cheer → sync → subscribe.

Signal path

One GPS tick, thousands of eyes—without touching MongoDB

  1. 1Runner GPSREST / Socket
  2. 2RedisHot path + pub/sub
  3. 3SpectatorsSSE · Socket.IO
  4. 4Cheer queueBull → FCM

Stack in production

Products & services engineered

Mobile · AI · Fitness
  • RAG recommendation engine

    Vector retrieval + LLM generation for custom training and diet plans from user data

  • LLM orchestration

    Prompt pipelines, context windows, and guardrails for safe fitness outputs

  • Redis + pub/sub

    Live race state, location channels, cheer broadcasts, rate limits

  • Socket.IO + SSE

    Runner sockets; zero-login spectator streams

  • Bull + FCM

    Intelligent cheer spacing, retries, push to runner devices

  • AWS Polly + S3

    Neural bilingual TTS, audio assets, GeoJSON route exports

  • MongoDB + embeddings store

    Users, races, subscriptions, and retrieval context for AI personalization

  • Strava · Superwall · IAP

    Activity sync, paywall webhooks, Apple and Google verification

Node.jsExpressFlutterMongoDBRedisVector DB / EmbeddingsRAGLLM APIsSocket.IOServer-Sent EventsBullFirebase Auth & FCMAWS PollyAWS S3ffmpegStrava APISuperwallGoogle Play IAPApple IAPTwilio / MessageCentralMapbox PolylineHelmet · Winston

Executive summary

CheerMy Run is an AI-native social running platform: live race sharing for spectators, intelligent voice cheers, and retrieval-augmented fitness coaching that customizes exercise and diet plans from each user’s onboarding profile, goals, device, and history. Intellixa Labs partnered as the engineering studio behind the production backend and AI systems—scaling the product past 25,000 users and approximately $51,000 USD in revenue.

The engagement combined product thinking with hard systems work: real-time infrastructure for race day, RAG for daily retention, and monetization hooks that convert engaged runners into subscribers.

The problem—and how Intellixa solved it

Problem 1 — Emotional gap on race day: Friends could not be at the course, and existing apps did not stream live encouragement. Intellixa built shareable race codes, public spectator APIs (cheer, snapshot, SSE stream) without accounts, Redis-backed GPS fan-out, and a Bull-managed cheer queue so audio never stacks destructively during marathons.

Problem 2 — Generic coaching: Users needed plans that respect experience level, favorite distances, running device, units, and club context. Intellixa implemented a RAG pipeline: embed and retrieve relevant user and activity context, augment LLM prompts, and output structured exercise and nutrition recommendations that update as new races and preferences arrive—not static content.

Problem 3 — Scale and revenue: Live features and AI must run profitably. Intellixa delivered OTP + Firebase auth, subscription verification (Google Play, Apple, Superwall webhooks), cron hygiene for races and entitlements, and observability-ready Node.js services—supporting 25K+ users and $51K USD revenue on a stack built to grow.

  • Intellixa scope: backend, real-time layer, AI/RAG fitness, voice, payments, Strava
  • Outcome: 25,000+ users, $51,190 USD revenue (production MongoDB), production-grade race + AI UX
  • Differentiator: user-data-driven plans + live social layer in one product

RAG-based fitness recommendations

CheerMy Run’s coaching layer uses retrieval-augmented generation—not a single prompt to a chatbot. At onboarding and over time, the platform collects structured runner context: demographics, experience, running device, shoe and gear preferences, distance goals, units (km/miles), audio preferences, and run-club affiliation. Race history, cheer engagement, and Strava-linked activity enrich the retrieval corpus.

When a user requests training guidance or diet planning, the system retrieves the most relevant slices of their profile and history from a vector index, composes an augmented prompt, and generates customized exercise blocks and meal guidance via LLM orchestration—with guardrails so outputs stay fitness-safe and on-brand. Plans evolve as new data arrives; the model does not hallucinate a generic marathon schedule for a 5K beginner.

  • Inputs: profile, goals, devices, past races, optional Strava activity
  • Pipeline: chunk → embed → retrieve → augment → generate → persist recommendations
  • User benefit: personalized exercise + diet plans, not template PDFs
  • Business benefit: higher retention and subscription conversion after personalized value

System architecture & tech stack

Clients include a Flutter mobile app for runners and a lightweight spectator web experience via deep link. The API layer is Express (/v1) with Socket.IO per race, SSE for public streams, and Bull workers for cheers and async AI jobs.

Data plane: MongoDB for durable users, races, notifications, subscriptions, and recommendation artifacts; Redis for live telemetry, pub/sub, OTP rate limits, and queue backing; vector storage for RAG retrieval; AWS S3 for audio, TTS, and GeoJSON routes. AI plane: embedding models, vector search, LLM APIs, AWS Polly SSML, and ffmpeg for voice-merge pipelines.

During active races, Redis is source of truth for GPS; MongoDB syncs on schedule and on endRace. AI workloads stay off the hot path—recommendations generate asynchronously while live races stay sub-second.

  • Runtime: Node.js, Express, Flutter
  • Data: MongoDB, Redis, vector DB / embeddings index, AWS S3
  • Real-time: Socket.IO, SSE, Bull, Firebase FCM
  • AI: RAG, LLMs, AWS Polly, route optimization algorithms
  • Integrations: Strava OAuth, Twilio/MessageCentral OTP, Superwall, Google Play, Apple IAP
  • Ops: Helmet, Winston, node-cron, horizontal-ready stateless API

Real-time race engine

When a runner updates location—REST progress or runner_location_update sockets—the backend validates the race is started, writes race_data:{code} in Redis, appends route segments with dynamic caps, and publishes to race:{code}:location. Spectators receive pace, distance, and map position without hammering MongoDB.

Cheer events broadcast on Redis timelines for spectator UI parity; FCM delivery follows queue spacing (default 10s per runner, 5s minimum gap, backpressure beyond five pending jobs). The result: marathon-scale cheer storms without stacked audio or push throttling meltdowns.

AI voice, audio pipelines & route intelligence

Beyond RAG coaching, CheerMy Run ships multiple AI layers for race day. AWS Polly (Joanna en-US, Mia es-MX) renders SSML-tuned cheers for outdoor audio; FCM payloads can trigger on-device TTS for instant text cheers. ffmpeg normalizes and concatenates multi-clip spectator voice notes into single MP3s on S3.

Post-race, RouteOptimizer denoises GPS, compresses polylines, and exports GeoJSON for sharing and Strava upload—clean maps and smaller payloads at scale.

Growth, Strava & monetization to $51K revenue

Strava integration complements live cheering: OAuth with encrypted tokens, post-race activity upload with optimized polylines, and social proof in the athlete’s permanent feed. Zero-login spectator endpoints drove viral race sharing; personalized AI coaching drove return visits; Superwall plus native IAP converted engaged users.

Intellixa wired subscription state to MongoDB, daily expiry cron, and optional assertActiveSubscription gates—aligning product loops with verified revenue across 25,000+ users.

Subscription revenue (production DB)

$51,190

Verified via MongoDB Compass · usersubscriptions collection

MongoDB Compass · Aggregations

MongoDB Compass aggregation showing $51,190 total subscription revenue from the CheerMy Run production database

Our production database doesn't lie.

Live aggregation on the same UserSubscription collection that powers entitlements and renewals—no slide-deck math.

Scaling a platform for CheerMy Run? Intellixa Labs ships production architecture, data platforms, and AI systems with the same discipline we brought to CheerMy Run—measurable outcomes and SEO-ready launch quality.

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