Technology Stack

Technical Stack Recommendations

1. Architecture Overview

Principles

1. Microservices Architecture - Modular, independently deployable
2. Cloud-Native Design - Containerized, elastic scaling
3. Security by Design - Zero-trust, encryption everywhere

2. Backend Technology

Primary: Java/Spring Boot

• Built-in Spring Security, OAuth2
• ACID compliance for transactions
• Proven in regulated industries
• Spring Boot 3.x, Spring Cloud

Secondary: Node.js

• WebSocket connections
• Push notifications
• Real-time updates

Hybrid Approach

• Java: Auth, Accounts, Payments, Cards, Ledger, KYC/AML
• Node.js: WebSocket, Notifications, Real-time
• Python: Fraud ML, Risk Scoring, Analytics

3. Mobile Development

Recommendation: Flutter

Criteria	Flutter	React Native	Native
Performance	Near-native	Good	Best
Code Sharing	95%+	85-90%	0%
Market Share	46%	35%	-

Why Flutter:

• Same UI across iOS/Android
• Single codebase
• No JS bridge
• Used by major banks

Stack: Bloc, GoRouter, Dio, Hive, local_auth

4. Database & Storage

• Primary: PostgreSQL 16
• Cache: Redis 7
• Queue: Kafka/RabbitMQ
• Documents: S3
• Search: Elasticsearch

5. Infrastructure

Cloud: AWS or GCP

Components:

• Kubernetes (EKS/GKE)
• Terraform
• GitHub Actions + ArgoCD
• Prometheus + Grafana
• CloudFlare (WAF)

6. Security

OWASP MASVS

• AES-256, TLS 1.3
• Biometric auth, 2FA
• Certificate pinning
• Code obfuscation

7. MVP Stack

• Backend: Java 21 + Spring Boot 3.2, Node.js 20
• Mobile: Flutter 3.x
• Data: PostgreSQL, Redis, Kafka
• Infra: AWS/GCP, K8s, Terraform
• Third-Party: Swan (BaaS), Stripe Issuing, Sumsub (KYC)