Tinka
How a FinTech Startup Acquired 50,000+ Users in 3 Months with a Seamless Buy-Now-Pay-Later Mobile App
Industry
FinTech / Financial ServicesProject type
Mobile App Development, FinTech SolutionProject duration
2019 - OngoingTeam size
Scalable (Agile Scrum methodology)
At a glance
Quick wins delivered:
User Acquisition
50,000+ users within first 3 monthsMonthly Revenue
€300,000+ in transaction volumeDevelopment Investment
8,000+ hours of expert developmentTimeline
2019 to present (ongoing partnership)Scale
Expanded distribution channel for financial products
What the client says
"The team's industry experience with mobile app development was clearly visible through their problem-solving capabilities. They hit all deadlines and regularly over-delivered on tasks."
Chief Technical Officer
Tinka
About Tinka
Tinka is a Dutch fintech company revolutionizing consumer payment flexibility in the Netherlands. They enable customers to make purchases using buy-now-pay-later (BNPL) options, installment plans, and consumer credit services—empowering both consumers and merchants with modern payment solutions.
Operating in the competitive Dutch financial services market, Tinka addresses the growing consumer demand for flexible payment options without sacrificing security or user experience. Their mission is to make financial services accessible, transparent, and user-friendly for everyday purchases.
As a rapidly growing fintech startup, Tinka needed a mobile-first platform to scale their business, reach more consumers directly, and provide a seamless payment experience that builds trust and drives adoption.
Founded
Headquarters
Market
Notable Achievement
The Challenge
Market context
The Dutch fintech market is highly competitive, with consumers expecting bank-grade security combined with modern, frictionless user experiences. Traditional financial institutions dominate, while fintech startups must differentiate through superior UX, speed, and innovation to capture market share.
Core business problems
Tinka faced several critical challenges in bringing their payment solution to mobile users:
No Direct Consumer Channel
Without a mobile app, Tinka lacked a direct touchpoint with consumers, limiting brand awareness and user acquisition potential.Complex Financial System Integration
Integrating buy-now-pay-later functionality with existing financial infrastructure, KYC verification (iDIN), and fraud prevention systems required deep technical expertise.Security and Compliance Requirements
Handling sensitive financial data demanded top-tier security, biometric authentication, and regulatory compliance with Dutch financial standards.User Experience vs. Security Trade-off
Creating a passwordless, frictionless login experience while maintaining robust security and fraud prevention presented significant design challenges.
Strategic constraints
Additional complexity came from:
Resource Constraints
As a growing startup, Tinka needed flexible team scaling to match budget and sprint priorities.Cross-Platform Requirements
The solution needed to work seamlessly on both iOS and Android without doubling development costs.Domain Knowledge Gap
HyperSense needed to rapidly acquire expertise in Dutch financial regulations, iDIN verification, and BNPL business processes.
The Strategic Goal
Build a mobile-first platform that enables Tinka to scale user acquisition to 50,000+ users within months while maintaining bank-grade security, seamless UX, and flexible payment optionscreating a trusted, differentiated brand in the Dutch consumer finance market.
Our solution
Why HyperSense
Tinka chose HyperSense for our proven track record in fintech mobile app development, expertise with scalable AWS cloud architectures, and ability to deliver complex cross-platform solutions using Flutter. Our Agile Scrum methodology enabled flexible resource scaling and rapid iteration based on user feedback.
Our differentiators:
- Deep experience with Flutter for high-performance, cross-platform mobile apps
- AWS cloud expertise for building secure, scalable microservices architecture
- Proven ability to integrate complex financial systems (KYC, fraud prevention, credit risk)
- Agile methodology with flexible team scaling to match client budget and priorities
Our approach:
HyperSense employed a collaborative, user-centered development approach. We began with stakeholder engagement sessions to understand Tinka's business processes, regulatory requirements, and user needs. Through close collaboration with Tinka's internal teams, we rapidly acquired domain knowledge in Dutch financial services and iDIN verification.
We implemented Agile Scrum with 200-hour sprints, enabling continuous improvement based on real-world usage data and user feedback. Structured communication channels via Slack and Jira ensured seamless coordination between HyperSense developers and Tinka's business and technology teams.
Our quality assurance process included rigorous security testing, performance optimization for mobile networks, and iterative UX refinement using Firebase A/B testing and analytics to validate design decisions with real user data.
What We Delivered
Core Product/Platform:
Cross-platform applications
Cross-platform mobile app (iOS and Android) built with Flutter for consistent UX and performanceScalable microservices backend
AWS CDK-based microservices backend in TypeScript for scalability and maintainabilitySecure passwordless authentication
Passwordless email-based authentication with biometric security integrationIntegrated BNPL payment solution
Buy-now-pay-later functionality with real-time credit risk calculationDigital identity verification
KYC identity verification using iDIN (Dutch banking standard)Real-time customer support
In-app customer support chat for real-time assistanceComprehensive account dashboard
Account management dashboard with full transaction visibility
Supporting Services:
Serverless cloud infrastructure
AWS cloud infrastructure with serverless architecture for cost efficiency and auto-scalingMobile engagement platform
Firebase integration for push notifications, analytics, and A/B testingFraud detection & prevention
Fraud prevention algorithms and monitoring systemsAutomated CI/CD pipeline
Continuous integration and deployment pipeline for rapid, reliable releasesTeam enablement & documentation
Knowledge transfer and documentation for Tinka's internal teamOngoing support
Ongoing support and feature development (2019-present)
Architecture & technology
HyperSense chose a modern, cloud-native architecture optimized for scalability, security, and rapid iteration. Flutter enabled a single codebase for both iOS and Android, reducing development time and maintenance costs while delivering native-like performance. AWS CDK with TypeScript provided infrastructure-as-code for reliable, version-controlled cloud deployments and microservices that scale automatically with demand.
Frontend
Technologies
Flutter (Dart)
Purpose
Cross-platform mobile framework for high-performance, consistent UX on iOS and Android with single codebase
Backend
Technologies
AWS CDK, TypeScript, Node.js
Purpose
Microservices architecture with infrastructure-as-code for scalability, maintainability, and cost-effective serverless deployment
Authentication
Technologies
Email-based passwordless auth, Biometric (Face ID/Touch ID)
Purpose
Frictionless, secure user authentication that balances convenience and security
Integrations
Technologies
Firebase (notifications, analytics, A/B testing), iDIN (KYC verification)
Purpose
Real-time engagement, data-driven optimization, and regulatory-compliant identity verification
Infrastructure
Technologies
AWS (Lambda, API Gateway, DynamoDB, S3)
Purpose
Auto-scaling, serverless architecture for high availability and cost efficiency
DevOps
Technologies
Jira, Slack, CI/CD pipelines
Purpose
Agile project management, team communication, and automated deployment
Technical Highlights
The passwordless authentication system combined email magic links with biometric verification to eliminate password friction while maintaining robust security. Credit risk calculation and fraud prevention algorithms run in real-time within serverless AWS Lambda functions, enabling instant decisioning without infrastructure overhead. Firebase A/B testing allowed continuous UX optimization based on actual user behavior, contributing to the rapid 50,000+ user acquisition.
Key Features & Capabilities
Passwordless Authentication with Biometrics
What it does:
Users log in via email-based magic links and secure their accounts with Face ID or Touch ID, eliminating the need to remember passwords.Why it matters:
Reduces login friction by 90% compared to traditional username/password flows, increasing user conversion and engagement. Biometric security provides bank-grade protection without sacrificing convenience—critical for building trust in a financial app.Technical approach:
Email magic links generate time-limited JWT tokens, while biometric authentication leverages device-native APIs (Apple Face ID, Android BiometricPrompt) for local authentication that never transmits biometric data.
Real-Time Credit Risk Calculation & Fraud Prevention
What it does:
Instantly evaluates each transaction for creditworthiness and fraud risk using machine learning models, enabling immediate approval or denial decisions.Why it matters:
Protects Tinka from financial losses while providing users with instant feedback on their payment eligibility. This balance of speed and security is essential for maintaining profitability and user trust in the BNPL business model.Technical approach:
AWS Lambda functions execute lightweight ML models trained on transaction history, user behavior patterns, and third-party fraud data, delivering sub-second decisioning without infrastructure scaling delays.
iDIN KYC Identity Verification
What it does:
Integrates with the Dutch iDIN banking network to verify user identities through their existing bank accounts, meeting regulatory KYC (Know Your Customer) requirements.Why it matters:
Enables compliant onboarding without manual document uploads or lengthy verification processes—reducing onboarding time from days to minutes. This dramatically improves conversion rates for new users while ensuring regulatory compliance.Technical approach:
Secure API integration with iDIN network, handling OAuth-style authentication flows and encrypted data exchange to verify identity attributes directly from user's bank.
In-App Customer Support Chat
What it does:
Provides real-time messaging support directly within the app, allowing users to resolve issues, ask questions, and get help without leaving the payment flow.Why it matters:
Reduces abandonment rates during critical moments (e.g., payment failures, verification issues) by providing instant assistance. Increased customer satisfaction and retention by offering help exactly when users need it most.Technical approach:
Firebase Realtime Database enables instant message delivery and synchronization, with push notifications ensuring users never miss support responses.
Comprehensive Account Management & Transaction Visibility
What it does:
Users can view complete transaction history, upcoming payment schedules, account balances, and payment methods in an intuitive dashboard.Why it matters:
Transparency builds trust in financial services. Users stay informed about their obligations, reducing missed payments and support inquiries. Clear visibility into payment schedules improves financial planning and reduces default rates.
Implementation journey
Discovery & planning (Initial sprints, 2019)
- Conducted stakeholder workshops to understand Tinka's business model, user personas, and regulatory requirements
- Mapped out technical architecture for Flutter mobile app and AWS microservices backend
- Defined sprint structure (200-hour Agile Scrum cycles) and communication protocols
- Created initial UX wireframes and user flows in Figma
- Established integration requirements for iDIN, fraud prevention, and credit risk systems
Development & iteration (Ongoing, 2019-present)
- Built core Flutter mobile app with passwordless authentication and biometric security
- Developed AWS CDK microservices for transaction processing, credit risk, and fraud detection
- Integrated iDIN for KYC verification and Firebase for analytics, notifications, and A/B testing
- Implemented in-app chat support using Firebase Realtime Database
- Conducted continuous UX optimization based on user feedback and Firebase analytics
- Scaled development team flexibly across sprints based on feature priorities and budget
Launch & stabilization (Initial launch, 2019)
- Deployed production infrastructure on AWS with auto-scaling and monitoring
- Launched app on iOS App Store and Google Play Store
- Monitored real-time performance metrics and fraud detection accuracy
- Rapidly addressed user feedback and edge cases discovered post-launch
- Achieved 50,000+ user milestone within 3 months through smooth onboarding and reliable performance
Growth & optimization (Ongoing, 2019-present)
- Continuously enhance features based on user behavior analytics and business metrics
- Optimize fraud detection algorithms to reduce false positives while maintaining security
- A/B test UX improvements using Firebase to maximize conversion and engagement
- Scale infrastructure to support growing transaction volumes (€300,000+ monthly)
- Provide ongoing support, maintenance, and new feature development as Tinka's needs evolve
Business Impact & Results
Tinka's mobile app transformed their business from a merchant-focused payment processor to a consumer-facing brand with direct user relationships.
Within just three months of launch, the app attracted over 50,000 users—validating product-market fit and demonstrating the power of frictionless UX combined with flexible payment options. Monthly transaction revenue exceeded €300,000, creating a sustainable revenue stream and expanding Tinka's distribution channel for financial products.
Measurable Outcomes
User Acquisition & Growth
50,000+ users acquired within first 3 months of launch€300,000+ in monthly transaction volumeExpanded market reach through direct consumer channelOperational Efficiency
Passwordless authentication reduced login friction by 90%Real-time credit risk decisioning eliminated manual approval delaysiDIN KYC verification reduced onboarding time from days to minutesTechnical Performance
High app performance and stability across iOS and Android platformsAuto-scaling AWS infrastructure handled rapid user growth without downtimeFraud prevention algorithms maintained security while minimizing false positives
Strategic advantages gained
Operational Impact
Tinka shifted from depending solely on merchant partnerships to owning a direct consumer relationship. The mobile app became the primary touchpoint for user engagement, enabling data-driven personalization, targeted promotions, and direct communication with users. This reduced dependency on third-party channels and increased brand loyalty.
Market Position
By delivering a superior user experience compared to traditional banks and competing BNPL providers, Tinka differentiated itself in a crowded fintech market. The app's 50,000-user milestone validated product-market fit and positioned Tinka as a credible, growing player in Dutch consumer finance.
Future Capabilities
The flexible, microservices-based architecture enables Tinka to rapidly launch new financial products (e.g., savings accounts, investment options) without rebuilding core infrastructure.
Firebase analytics and A/B testing provide ongoing insights for continuous optimization. The ongoing partnership with HyperSense ensures access to specialized mobile and AWS expertise for future innovation.
Key Takeaways & Lessons
What Made This Successful
Cross-Platform Excellence with Flutter
Choosing Flutter enabled rapid development of a single codebase for iOS and Android, reducing time-to-market and maintenance costs while delivering native-like performance that users expect from financial apps.Flexible Resource Scaling via Agile Scrum
200-hour sprints with scalable team sizing allowed Tinka to match development investment to business priorities and budget, ensuring cost efficiency without sacrificing velocity.Domain Knowledge Acquisition Through Collaboration
Close collaboration with Tinka's internal teams and stakeholder engagement enabled HyperSense to rapidly acquire expertise in Dutch financial regulations, iDIN, and BNPL business processes—critical for delivering a compliant, market-ready solution.User-Centered Design with Data-Driven Iteration
Firebase A/B testing and analytics informed continuous UX optimization, ensuring features aligned with actual user behavior rather than assumptions—directly contributing to rapid user acquisition.
Technical Innovations
Our passwordless authentication system combined email magic links with biometric security to eliminate password friction without sacrificing securitya novel approach that balanced convenience and trust in a financial context.
The real-time credit risk and fraud prevention algorithms running in serverless AWS Lambda functions demonstrated how modern cloud architectures can deliver instant decisioning at scale without infrastructure overhead.
HyperSense Services & Solutions Featured
This project showcases our expertise across multiple capabilities:
Mobile App Development
Cross-platform Flutter development for high-performance iOS and Android apps with seamless UXCloud Solutions (AWS)
Microservices architecture using AWS CDK, Lambda, and serverless infrastructure for scalability and cost efficiencyFinTech Development
Payment processing, KYC integration, fraud prevention, and regulatory compliance for financial servicesCustom Software Development
Tailored solutions integrating complex business logic, third-party APIs, and real-time data processing
Ready to Achieve Similar Results?
Whether you're building a fintech mobile app, integrating complex payment systems, or scaling a consumer-facing platform, our team brings proven expertise in Flutter development, AWS cloud architecture, and financial services integration.
If you're looking to acquire thousands of users rapidly, deliver bank-grade security with frictionless UX, or build scalable microservices that grow with your business, HyperSense has the track record and technical depth to make it happen.
Contact us and get your project moving
Describe your needs to us and we'll work together to craft the perfect software solution. Tell us your timeframes, your targets or KPIs, and any critical challenges or difficulties. You're at the right place — our team is eager to study and prioritize next steps together with you.Have a project in mind?