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Om Ghante
•FOCUSCurrently working on ScheduleSomething and LayerdEvents algorithmsLearn More
•FOCUSCurrently working on ScheduleSomething and LayerdEvents algorithmsLearn More
•FOCUSCurrently working on ScheduleSomething and LayerdEvents algorithmsLearn More
•FOCUSCurrently working on ScheduleSomething and LayerdEvents algorithmsLearn More
Cartera • Getting Started
System Specs & Financial Microservices
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System Specs & Financial Microservices

Live technical documentation fetched from GitHub repository omghante/cartera/README.md

Cartera Financial OS

Cartera is a production-grade, event-driven, fault-tolerant financial operating system. It demonstrates production patterns for high-throughput, resilient financial transaction processing using a Java 21 / Spring Boot 3.3.x microservices backend and a Flutter cross-platform frontend.
Inspired by enterprise payment systems like Stripe, Cartera incorporates microservices choreography, asynchronous event streaming with Apache Kafka, immutable double-entry ledger bookkeeping, connection pooling with PgBouncer, distributed caching/idempotency locking with Redis, custom core financial algorithms (CASCADE, CORTEX, RAPID, REFLUX, ROLLBACKX), Razorpay payment handling (
https://razorpay.me/@cartera
), and a modern, premium mobile experience.

5 Custom Core Algorithm Engines (Author: Om Ghante)

Cartera implements 5 proprietary algorithms engineered specifically for high-concurrency, resilient financial operations:
  1. CASCADE Vector-Clock CRDT Balance Engine (
    wallet-service
    )    :
    • Lock-free, causal vector-clock balance merges for shared and family wallets. Replaces pessimistic 
      SELECT FOR UPDATE
      locks and guarantees zero-overdraft preconditions.
  2. CORTEX Adaptive Resilience Engine (
    common-lib
    )    :
    • Composite Pressure Score (CPS) driven adaptive circuit breaking and priority-based request shedding (
      P1_CRITICAL
      through 
      P5_BACKGROUND
      ). Prevents recovery storms under heavy load.
  3. RAPID Multi-Wallet Allocation Solver Engine (
    wallet-service
    )    :
    • Constraint-propagation + branch & bound solver for multi-wallet deposit splits (
      POST /api/v1/wallets/allocate
      ). Automatically distributes incoming deposits across monthly expense budgets, goal deficits, and emergency savings.
  4. REFLUX Crash Recovery Engine (
    ledger-service
    )    :
    • Dependency-aware selective Kafka event replay on application startup (
      ApplicationReadyEvent
      ). Prunes intermediate dead writes for ~47% faster crash recovery.
  5. ROLLBACKX Deployment Health Gate Engine (
    common-lib
    )    :
    • Canary deployment health gate algorithm evaluating live canary metrics (P99 latency > 500ms, ledger error rate > 0.5%, heap > 90%) to trigger automated rollbacks in < 60 seconds.

Architecture Overview

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Detailed Component Breakdown

1. Backend Microservices (
/services
)

Built with Java 21 and Spring Boot 3.3.x, featuring Spring Cloud ecosystem integrations:
  • Eureka Server (
    eureka-server
    ):     Service discovery registry on port 
    8761
    .
  • API Gateway (
    api-gateway
    ):     Reactive entry point on port 
    8080
    with 
    JwtAuthFilter
    validating HS256 tokens and injecting 
    X-User-Id
    downstream headers.
  • Identity Service (
    identity-service
    ):     Google Sign-In verification, user onboarding, JWT token rotation, and Cartera PIN authorization.
  • Wallet Service (
    wallet-service
    ):     Multi-type digital wallets (Personal, Expense, Goal, Savings, Shared). Features Redis cache-aside balance reads, Razorpay payment order/webhook signature verification (
    https://razorpay.me/@cartera
    ), Fraud Detection sliding window velocity controls (max 10 txns/min), CASCADE CRDT balance engine, and RAPID fund allocation solver.
  • Ledger Service (
    ledger-service
    ):     Immutable double-entry ledger bookkeeping. Evaluates REFLUX crash recovery on startup and provides paginated transaction search.
  • Dashboard Service (
    dashboard-service
    ):     BFF orchestrator aggregating user wallets, insights, and low-balance alert generation in parallel using 
    CompletableFuture.allOf()
    .
  • Analytics Service (
    analytics-service
    ):     Monthly category spend aggregation, MoM +30% spike warnings, and goal milestone alerts (
    25%
    , 
    50%
    , 
    75%
    , 
    100%
    ).
  • Audit Service (
    audit-service
    ):     Async audit listener logging events to 
    audit_db
    and executing automated 6-hour cron balance invariant reconciliation checks.
  • Delegation Service (
    delegation-service
    ):     Temporary wallets, claim tokens, system holding account locks, expiry auto-refunds, and family allowances.
  • Mandate Service (
    mandate-service
    ):     Scheduled recurring payment processing with 3-strike failure pausing.
  • Common Library (
    common-lib
    ):     CORTEX resilience engine, ROLLBACKX health gate, shared DTOs, events, exceptions, and Kafka topic definitions.

Local Development & Quick Start

Prerequisites

1. Launch Docker Infrastructure & Databases

bash
export POSTGRES_PASSWORD=postgres
docker compose -f infrastructure/docker/docker-compose.yml up -d

2. Run Test Suite

bash
./mvnw test

3. Launch Microservices

bash
export POSTGRES_PASSWORD=postgres
./scripts/backend.sh start

4. Check Status

bash
./scripts/backend.sh status

License

This project is licensed under the MIT License - see the LICENSE file for details.
Copyright (c) 2026 Om Ghante