iMumz
A pregnancy app, rebuilt to scale to 100K+ mothers.
The brief, in a paragraph.
iMumz needed to scale their pregnancy wellness app to serve over 100K expecting mothers across India while maintaining a crash-free, performant experience. The existing codebase had stability issues causing user drop-off, and new engagement features needed to be shipped rapidly without breaking the core experience. The team required engineering leadership to own the mobile platform end-to-end.
Every project has a story before it has a solution. Here's the part nobody writes on the case-study cover.
Stability was eroding trust release after release.
iMumz needed to scale their pregnancy wellness app to serve over 100K expecting mothers across India while maintaining a crash-free, performant experience. The existing codebase had stability issues causing user drop-off, and new engagement features needed to be shipped rapidly without breaking the core experience.
- 01Crash-prone codebase causing silent user churn at scale
- 02Multiple state-management styles drifting in the same app
- 03No A/B framework — every product call was an opinion
- 04Manual releases with multi-day cycle times and rollback fear
Architect, instrument, then ship.
Took full ownership of the Flutter mobile platform as Software Engineer II. Refactored the architecture to BLoC pattern for predictable state management, implemented comprehensive Crashlytics monitoring, and established automated CI/CD pipelines with Fastlane and GitHub Actions. Led the development of A/B testing infrastructure that enabled data-driven feature rollouts.
BLoC as the only state pattern
One predictable mental model across the app. Removed two competing patterns over six weeks of patient migration.
Crashlytics on every critical path
Every navigation transition, payment hop, and content load got telemetry. Issues surfaced in hours, not weeks.
A/B testing pipeline
Built a Firebase Remote Config + analytics pipeline so every product hypothesis was a measurable bet, not a meeting.
Fastlane + GitHub Actions CI/CD
Push to main → versioned build on Play Console → staged rollout. Released Friday afternoon with confidence.
A platform engineered to ship — not just to run.
What we built isn't a single feature; it's a way of working. Every feature now lands instrumented, tested, and behind a remote flag. Every developer can ship to staging without asking permission.
- 01Migrated 60% of screens to BLoC over 6 sprints, no regressions
- 02Crash-free sessions improved to 99.2% across iOS + Android
- 03Built 14 A/B experiments that ran without engineering involvement
- 04Halved the average bug-to-fix-to-release cycle
- 05Mentored two junior developers from feature work to ownership
The numbers, after the dust settled.
From a baseline 96.4% to 99.2% — sustained over 14 releases.
A/B-tested onboarding lifted DAU/MAU ratio across cohorts.
Sub-2-second cold starts even on low-end Android devices.
Cut the average release cycle from 8 days to 4.
What changed, measured.
| Metric | Before | After |
|---|---|---|
| Crash-free sessions | 96.4% | 99.2% (sustained over 14 releases) |
| Release cycle time | 8 days, manual, multi-stage | 4 days, automated via Fastlane + GitHub Actions |
| State management | 3 competing patterns drifting across the app | 1 (BLoC), with 60% of screens migrated in 6 sprints |
| A/B experiments running without engineering | 0 | 14, via Firebase Remote Config + analytics pipeline |
What it's built with.
- Flutter
- Dart
- BLoC
- Riverpod (gradual)
- Firebase
- REST APIs
- Remote Config
- Crashlytics
- Unit Tests
- Widget Tests
- Fastlane
- GitHub Actions
- Play Console
From the blog.
Building Healthcare Apps with Flutter: Compliance, Security & Best Practices
A comprehensive guide to building HIPAA-compliant healthcare apps with Flutter. Covers regulatory requirements, security implementation, telemedicine features, health data integration, and real-world lessons from shipping the iMumz pregnancy app.
How to Hire a Flutter Developer in India: Complete Guide
A comprehensive guide to hiring a Flutter developer in India. Covers where to find developers, vetting processes, rate ranges by experience level, interview questions, engagement models, red flags, and best practices for remote collaboration.
“Yashraj consistently demonstrates full ownership of projects, ensuring timely delivery with precision and attention to detail.
I build Flutter apps, Next.js websites, and full-stack products for ambitious teams.
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