Ensembl mobile app showing community feed and conversations

Ensembl Community Networking Platform

Q: How much does it cost to rescue and modernize a legacy mobile app?

The cost depends on the app's complexity, number of bugs, and required upgrades. Typical legacy app rescue projects range from $15,000 to $80,000+ depending on codebase size, framework upgrades needed, and feature additions. We provide free consultations to assess your app and provide accurate estimates. Our approach focuses on stabilization first, then incremental improvements.

Q: How long does a React Native upgrade take?

A major React Native upgrade (like 0.76 to 0.81) typically takes 3-6 weeks for a medium-sized app with 50+ screens. The timeline depends on custom native modules, third-party dependencies, and breaking changes between versions. We upgraded Ensembl from 0.76 to 0.81 in just 1 month, including Firebase SDK and Android SDK updates. Our systematic approach minimizes risks and ensures thorough testing.

Q: Can you take over an app built by another team?

Yes, we specialize in taking over existing codebases from other development teams or agencies. We start with a comprehensive code audit to understand the architecture, identify technical debt, and prioritize fixes. With Ensembl, we inherited a codebase with 200+ bugs and successfully stabilized it while adding new features. Our dedicated team approach ensures continuity and knowledge transfer.

Q: What's involved in rebuilding a chat system for a mobile app?

Rebuilding a chat system involves real-time messaging infrastructure (often using Socket.io or Firebase), message persistence, file/media sharing, read receipts, typing indicators, push notifications, and offline support. For Ensembl, we rebuilt the entire chat from scratch with document sharing, reactions, mentions, voice messages, and read/unread status. A complete chat rebuild typically takes 6-10 weeks depending on required features.

Q: How do you fix bugs without breaking existing features?

We use systematic bug tracking, comprehensive testing protocols, and gradual rollout strategies. Each fix is tested in isolation, then regression tested against existing features. For Ensembl's 200+ bugs, we prioritized critical issues first (crashes, data loss), then UI/UX problems, then minor improvements. We maintain detailed documentation and use feature flags to control rollouts safely.

Q: Do you provide ongoing support after app stabilization?

Yes, most clients opt for ongoing mobile app maintenance after initial rescue work. We offer flexible retainer arrangements for continued bug fixes, feature additions, OS updates, and performance optimization. Ensembl has been an ongoing partnership for 6+ months with regular sprints for new features and improvements.

Q: What if my app has 200+ bugs? Where do you even start?

We start with triage and prioritization. Critical bugs (crashes, data loss, security issues) are fixed first. Then we address user-facing bugs that impact experience. Finally, we tackle minor issues and technical debt. For Ensembl, we categorized all 200+ bugs by severity, fixed critical issues in the first month, then systematically worked through the backlog while adding new features in parallel.

Q: Can you upgrade React Native without rewriting the whole app?

Yes, in most cases major React Native upgrades can be done incrementally without full rewrites. We upgrade dependencies in stages, fix breaking changes methodically, and test thoroughly at each step. Complete rewrites are rarely necessary unless the codebase is beyond repair. For Ensembl, we upgraded from 0.76 to 0.81 without rewriting any core features — just systematic dependency updates and compatibility fixes.

Q: How do you handle Firebase migrations in React Native apps?

Firebase SDK updates often introduce breaking changes in authentication, Firestore queries, and storage APIs. We audit all Firebase usage, update to new API patterns, migrate deprecated methods, and test authentication flows thoroughly. For Ensembl, we updated Firebase SDK alongside the React Native upgrade, ensuring all real-time features (chat, notifications) continued working seamlessly.

Q: What's the difference between bug fixing and refactoring?

Bug fixing addresses specific broken functionality or unintended behavior. Refactoring improves code structure, readability, and maintainability without changing external behavior. For legacy apps, we often do both: fix immediate bugs to stabilize the app, then refactor problem areas to prevent future issues. With Ensembl, we fixed 200+ bugs while also refactoring the chat system architecture for better long-term maintenance.

We rescued and modernized this French community networking app — upgrading React Native, rebuilding the chat system, and fixing 200+ bugs across 50+ screens.

Social Networking

Mobile App Development

React Native Upgrade

Legacy App Rescue

About the Client

Ensembl

Ensembl is a French community networking mobile application that enables users to connect within neighborhoods, organizations, and interest-based groups. The app features real-time chat, content publishing, events management, and community administration tools.

Built for iOS and Android using React Native, Ensembl serves communities across France with features designed for local engagement, private group communication, and event coordination.

Results

50+

App screens stabilized

200+

Bugs fixed

1 month

React Native upgrade

6+ months

Ongoing partnership

Goal & Outcome

Goal

Ensembl had accumulated over 200 bugs across 2 years of development by a previous team. User complaints were rising, critical features were broken, and the outdated React Native 0.76 framework blocked new feature development and security updates.

The client needed a complete rescue: stabilize the app, upgrade the framework, rebuild the broken chat system, and add community administration tools — all while maintaining service for existing users.

Outcome

We took over the codebase using our mobile app development expertise and executed a systematic rescue: upgraded React Native from 0.76 to 0.81 in 1 month, fixed all 200+ bugs through rigorous testing, and rebuilt the chat system from scratch with modern real-time features.

Using our product development approach, we added 20+ new features including community administration, restricted groups, dark theme, and deep linking — transforming a broken app into a stable, modern platform.

Need a social app that actually connects people?

We've built friend-making platforms, professional networking apps, and niche community tools across industries. Get your cross-platform MVP to market in 2-3 months.

Before

Traditional Process

Outdated React Native 0.76

Old framework version blocked security updates and new features

200+ unresolved bugs

Critical issues, broken features, and poor user experience

Broken chat system

Unreliable messaging with missing features and frequent crashes

No admin tools

Community managers lacked moderation and member management capabilities

Technical debt accumulation

Outdated dependencies, poor code quality, hard to maintain

After

Digital Solution

Modern React Native 0.81

Latest framework with security patches and new capabilities

Stable, bug-free app

All critical bugs fixed, smooth user experience restored

Rebuilt real-time chat

Complete chat with file sharing, reactions, mentions, voice messages

Full admin panel

In-app moderation, user management, post control, join requests

Clean, maintainable codebase

Updated dependencies, TypeScript, ready for future development

Key Features:

Real-Time Chat

Complete chat system with document sharing, message reactions, mentions, voice messages, and read/unread indicators.

Restricted Communities

Gated access control with join requests, admin approval flow, and content protection for private groups.

Deep Linking

Universal links for both iOS and Android with environment-based configuration and proper redirection handling.

Push Notifications

Full notification system with permission flows, configurable notification levels, and unread badges.

Process Flow

Framework Upgrade

Upgraded React Native from 0.76 to 0.81 with Firebase and Android SDK updates, ensuring compatibility and stability with minimal user disruption.

Chat System Rebuild

Rebuilt real-time chat using Socket.io and Firebase with modern features like reactions, typing indicators, voice messages, and document sharing.

Bug Fixing & Stabilization

Resolved 200+ bugs across mobile and web platforms, including crashes, notification issues, UI problems, and data synchronization errors.

New Features & Admin Tools

Delivered 20+ new features including community admin tools, moderation controls, dark mode, events module, and improved app navigation.

🏆 Result

A stabilized, modern community networking app with upgraded framework, rebuilt chat system, comprehensive admin tools, and 200+ bug fixes — ready for continued growth and new features. The ongoing 6+ month partnership demonstrates the success of our systematic app rescue approach.

Under the Hood

Mobile & Frontend

Cross-platform mobile and frontend technologies used for building scalable, high-performance applications.

React Native

React

Type Safety & Development

Strongly typed development setup improving maintainability, scalability, and long-term code quality.

TypeScript

Backend & Real-time Services

Real-time backend infrastructure for authentication, messaging, and live data synchronization.

Firebase

FaQ

How much does it cost to rescue and modernize a legacy mobile app?

Legacy mobile app rescue projects typically range from $15,000 to $80,000+, depending on codebase size, bug volume, framework upgrades, and required feature improvements. We start with stabilization and then incrementally modernize the system.

How long does a React Native upgrade take?

A major React Native upgrade usually takes 3–6 weeks for a medium-sized app. It depends on native modules, dependencies, and breaking changes. Systematic upgrades ensure stability without disrupting production users.

Can you take over an app built by another team?

Yes, we specialize in inheriting and stabilizing existing codebases. We begin with a full audit, fix critical issues first, and gradually improve architecture and features without disrupting existing users.

What’s involved in rebuilding a chat system for a mobile app?

A modern chat system includes real-time messaging, media sharing, notifications, read receipts, typing indicators, and offline support. Rebuilding it typically takes 6–10 weeks depending on complexity.

How do you fix bugs without breaking existing features?

We prioritize bugs by severity, fix critical issues first, and use regression testing and isolated deployments to ensure existing features remain stable during updates.

Do you provide ongoing support after app stabilization?

Yes, we offer ongoing maintenance and development support including bug fixes, OS updates, performance optimization, and new feature development through flexible retainers.

What if my app has 200+ bugs? Where do you even start?

We start with structured triage: fixing crashes and critical issues first, then user-impacting bugs, and finally minor issues and technical debt while keeping the app stable throughout.

Can you upgrade React Native without rewriting the whole app?

Yes, most React Native upgrades can be done incrementally. We update dependencies step by step, fix breaking changes, and avoid full rewrites unless the codebase is fundamentally unstable.

How do you handle Firebase migrations in React Native apps?

We carefully migrate Firebase SDKs by updating APIs, fixing deprecated methods, and testing authentication, database, and real-time features to ensure uninterrupted functionality.

What’s the difference between bug fixing and refactoring?

Bug fixing resolves incorrect behavior, while refactoring improves code structure and maintainability. We often do both to stabilize the app and improve long-term scalability.

Risk-Free Start

Your Free Trial Sprint

Week 1

Meet your team

Slack channel, assigned developer, daily standups. First code committed to your GitHub.

Week 2

Working prototype delivered

Technical spike or prototype complete. Architecture + budget roadmap for the full build.

You keep everything. Zero cost. Zero commitment.

Oleg Kalyta

Founder & AI Lead

What happens next:

1.You submit—We review within 24 hours
2.15-minute scoping call—We align on trial goals
3.Developer assigned—Within 48 hours
4.Working code in your repo—By end of Week 1