How a Leading Bank Migrated 50 Million Users and Reclaimed Ownership of Its Digital Experience
Note: Certain customer details have been anonymized to respect confidentiality agreements and enterprise security policies while preserving the accuracy and integrity of the outcomes described.
At a Glance
Industry: Banking and Financial Services
Region: Asia-Pacific
Scale: 50M+ app downloads · 13M+ monthly active users
Challenge: Break vendor lock-in, regain frontend ownership, and modernize a large-scale consumer banking app without disrupting millions of users
Solution: FlutterFlow Enterprise as the standardized foundation for in-house frontend modernization
Results:
- Migrated high-impact user journeys from a legacy vendor platform
- Reclaimed ownership of frontend UI and release cycles
- Accelerated feature delivery from weeks to days
- Supported 50M+ downloads with consumer-grade performance
- Established a scalable in-house frontend engineering capability
Background & Overview
This leading Indian private sector bank operates one of the largest consumer banking applications in the country, with more than 50 million downloads and over 13 million monthly active users.
Its digital strategy is anchored in a customer-first philosophy focused on intuitive, always-available, personalized banking experiences. At this scale, even minor technical changes carry significant operational and reputational risk.
For years, the bank relied on a vendor-based digital banking platform to power its mobile frontend. While stable in early phases of digitization, the model constrained agility as digital expectations evolved and competitive pressure intensified.
The Challenge
As digital ambitions expanded, structural limitations became clear:
Vendor Dependency
Frontend changes required formal change requests through an external provider, slowing iteration and tying innovation cycles to contractual processes.
Limited Frontend Ownership
The engineering team had restricted visibility into the underlying UI code, reducing control over optimization, experimentation, and long-term architectural direction.
Performance Constraints
Legacy hybrid wrappers introduced performance ceilings that made it difficult to match the fluid responsiveness of leading consumer applications.
Scale and Risk Exposure
With tens of millions of users, a full application rewrite carried unacceptable risk. Modernization needed to occur incrementally without affecting availability or customer trust.
Success Criteria
Leadership aligned on a strategic mandate:
- Reclaim ownership of the frontend experience
- Reduce dependency on vendor-controlled release cycles
- Maintain security and performance at national scale
- Modernize high-impact journeys without disrupting platform stability
- Establish an in-house engineering model capable of long-term innovation
The Solution
To modernize the mobile experience while maintaining stability at scale, the bank adopted FlutterFlow Enterprise as the standardized foundation for frontend migration and new journey development.
The initiative focused on accelerating delivery, enforcing architectural discipline, and embedding modernization expertise alongside the internal engineering team.
Accelerated Journey Modernization
Visual development and reusable components enabled rapid rebuilding of high-impact user journeys. Internal engineers focused on business logic, security integration, and backend microservices while frontend construction progressed in parallel.
Enforced Architectural Control
The bank regained full ownership of its UI code. Generated output adhered to clean architecture principles and remained readable, extensible, and compatible with the bank’s microservices-based backend environment. Performance improvements followed the transition to a fully native Flutter implementation.
Engineering Partnership and Scale
A dedicated internal team with a builder-oriented mindset partnered closely with FlutterFlow Enterprise during the migration. Complex integrations, UI reconstruction, and deployment strategy were executed collaboratively, allowing the bank to move critical journeys in phases. This approach expanded internal capability while reducing reliance on vendor-managed infrastructure.
The Rollout
Phase 1: Critical Journeys First
The bank identified high-impact customer journeys and prioritized their migration. These journeys were rebuilt using FlutterFlow and integrated into the existing application framework.
Phase 2: Incremental Coexistence
Modernized components were deployed alongside legacy systems, allowing performance and stability to be validated at scale. This phased approach reduced migration risk while maintaining platform continuity.
Phase 3: Progressive Transition
Over time, core experiences shifted to the new architecture, reducing dependency on the legacy vendor stack and increasing internal control over release cycles and feature delivery.
The Outcomes
Reclaimed Frontend Ownership
The bank now controls its UI codebase and release cadence without external change request cycles.
Accelerated Innovation
Feature iterations that previously required extended vendor coordination now move through internal engineering workflows in days.
Enterprise-Scale Performance
The application continues to support more than 50 million downloads and maintains strong consumer ratings, demonstrating performance at national scale.
Future-Ready Engineering Model
The migration established an internal frontend capability aligned with the bank’s microservices architecture and long-term digital roadmap.
What It Means for Engineering Leaders
At enterprise scale, digital experience ownership directly influences innovation speed, architectural flexibility, and competitive differentiation.
By internalizing frontend development with FlutterFlow Enterprise, this bank transitioned from vendor dependency to structured in-house control while maintaining performance and stability across tens of millions of users.
The result is a scalable engineering model that supports continuous modernization without compromising customer trust.
Looking for a partner, not just a platform?
Book a consultation to explore how FlutterFlow Enterprise can support your modernization strategy.