A real-time risk control engine for cryptocurrency trading platforms that detects suspicious trading patterns, monitors compliance, and prevents financial losses using Apache Flink CEP (Complex Event Processing).
The Crypto Risk Engine is a sophisticated real-time monitoring system that analyzes cryptocurrency trading activity across multiple exchanges. It combines real-time risk scoring for every trade with complex pattern detection to identify market manipulation, compliance violations, and abnormal trading behavior.
- Real-time Risk Analysis: Comprehensive risk scoring for every trade within milliseconds
- Complex Pattern Detection: CEP-based detection of wash trading, spoofing, volume spikes, and flash crashes
- Multi-exchange Monitoring: Unified risk monitoring across Binance, Coinbase, Kraken, and other exchanges
- Compliance Enforcement: Automated regulatory compliance checks and reporting
- Scalable Architecture: Built on Apache Flink for high-throughput, low-latency processing
- Schema Evolution: Avro-based data contracts for type safety and backward compatibility
- RocksDB State Backend: High-performance state management with Minio checkpoint storage
- Elasticsearch Integration: Real-time analytics and dashboarding capabilities
graph TB
subgraph DataGeneration [Data Generation Layer]
A[Spring Boot Trade Producer] --> B[Kafka Cluster]
A --> C[H2 Database]
end
subgraph Processing [Real-time Processing Layer]
B --> D[Flink CEP Risk Engine]
D --> E[Risk Analyzed Trades]
D --> F[Risk Alerts]
subgraph FlinkInfra [Flink Infrastructure]
G[RocksDB State Backend] --> D
H[Minio Checkpoint Storage] --> D
end
end
subgraph Storage [Storage & Analytics]
E --> I[Risk Analyzed Trades Topic]
F --> J[Risk Alerts Topic]
I --> K[Elasticsearch Sink Connector]
K --> L[Elasticsearch Cluster]
J --> M[Spring Boot Reporting Service]
L --> M
M --> N[Web Dashboard]
M --> O[Mobile Platform]
C --> P[Trade Audit Trail]
end
subgraph Infrastructure [Infrastructure]
Q[Schema Registry] --> B
Q --> D
R[Monitoring] --> D
end
style A fill:#e1f5fe
style D fill:#f3e5f5
style E fill:#e8f5e8
style F fill:#ffebee
style G fill:#fff3e0
style H fill:#fff3e0
style L fill:#fce4ec
style M fill:#e8f5e8
sequenceDiagram
participant TP as Trade Producer
participant K as Kafka
participant FE as Flink Engine
participant CEP as CEP Patterns
participant RA as Risk Analyzer
participant SINK as Kafka Sinks
participant ES as Elasticsearch
participant RS as Reporting Service
participant UI as Web/Mobile UI
TP->>K: CryptoTrade (Avro)
K->>FE: Stream Trades
FE->>RA: Real-time Risk Analysis
RA->>SINK: RiskAnalyzedTrade
FE->>CEP: Pattern Detection
CEP->>SINK: RiskAlert
SINK->>K: RiskAnalyzedTrade Topic
SINK->>K: RiskAlert Topic
K->>ES: Elasticsearch Sink Connector
ES->>RS: Risk Data Query
K->>RS: Real-time Alerts
RS->>UI: Dashboard Updates
For demonstration purposes, the system includes a Spring Boot Trade Producer Service that simulates realistic trading activity:
- Multiple Users: Generates trades from different user accounts with varying risk profiles
- Multiple Exchanges: Simulates trading across Binance, Coinbase, Kraken, FTX, and KuCoin
- Realistic Patterns: Includes normal trading, wash trading, spoofing, and volume spikes
- Configurable Rates: Adjustable trade generation frequency for testing
POST /api/trades/produce
Content-Type: application/json
{
"userId": "USER_001",
"customerId": "CUST_1001",
"symbol": "BTC/USDT",
"side": "BUY",
"quantity": 0.5,
"price": 45000.0,
"orderType": "LIMIT",
"exchange": "BINANCE"
}POST /api/admin/mock-trading/start- Apache Flink 1.17.1: Stream processing engine with CEP
- Apache Kafka 3.4.0: Message bus for event streaming
- Apache Avro 1.11.4: Data serialization and schema registry
- Spring Boot 3.1.5: Trade producer and reporting service
- Elasticsearch 8.0+: Real-time analytics and search
- RocksDB: High-performance state backend for Flink
- Minio: S3-compatible checkpoint storage
- H2 Database: In-memory storage for trade audit
graph LR
A[Avro Schemas] --> B[Code Generation]
B --> C[Java Classes]
C --> D[Trade Producer]
C --> E[Risk Engine]
C --> F[Schema Registry]
style A fill:#fff3e0
style C fill:#e8f5e8
- Java 11+
- Apache Kafka 3.4+
- Docker & Docker Compose
- Maven 3.6+
git clone https://github.com/codedstreams/crypto-risk-engine.git
cd crypto-risk-engine
# Build data contracts first
cd data-contracts
mvn clean install
# Build trade producer
cd ../trade-producer
mvn clean package
# Build risk engine
cd ../risk-engine
mvn clean packagedocker-compose up -d
# Create Kafka topics
kafka-topics.sh --create --topic crypto-trades --bootstrap-server localhost:9092 --partitions 3 --replication-factor 1
kafka-topics.sh --create --topic risk-alerts --bootstrap-server localhost:9092 --partitions 3 --replication-factor 1
kafka-topics.sh --create --topic risk-analyzed-trades --bootstrap-server localhost:9092 --partitions 3 --replication-factor 1{
"name": "risk-analyzed-trades-es-sink",
"config": {
"connector.class": "io.confluent.connect.elasticsearch.ElasticsearchSinkConnector",
"tasks.max": "1",
"topics": "risk-analyzed-trades",
"connection.url": "http://elasticsearch:9200",
"type.name": "_doc",
"key.ignore": "true",
"schema.ignore": "true",
"value.converter": "io.confluent.connect.avro.AvroConverter",
"value.converter.schema.registry.url": "http://schema-registry:8081"
}
}# Start Trade Producer (Terminal 1)
cd trade-producer
mvn spring-boot:run
# Start Risk Engine (Terminal 2)
cd risk-engine
flink run target/risk-engine-1.0.0.jar \
--kafka.bootstrap.servers localhost:9092 \
--schema.registry.url http://localhost:8081 \
--minio.endpoint http://localhost:9000 \
--state.backend.rocksdb true
# Start Reporting Service (Terminal 3)
cd reporting-service
mvn spring-boot:run# Start mock trading
curl -X POST http://localhost:8080/api/admin/mock-trading/start
# Check producer stats
curl http://localhost:8080/api/admin/stats
# Access dashboard
open http://localhost:8082/dashboardgraph LR
A[Trade 1: $1K] --> B[Trade 2: $2.5K]
B --> C[Trade 3: $6K]
C --> D[π¨ VOLUME_SPIKE Alert]
style D fill:#ff6b6b
Pattern: 3+ trades with increasing notional values (>150% growth) within 2 minutes
graph TB
A[BUY 1000 ADA] --> B[SELL 950 ADA]
B --> C[BUY 1050 ADA]
C --> D[π¨ WASH_TRADING Alert]
style D fill:#ff6b6b
Pattern: BUY β SELL β BUY with similar quantities within 1 minute
graph LR
A[Single Trade] --> B{Check Thresholds}
B -->|BTC > $500K| C[π¨ LARGE_ORDER]
B -->|ETH > $250K| C
B -->|SOL > $100K| C
style C fill:#ff6b6b
graph LR
A[SELL] --> B[SELL]
B --> C[SELL]
C --> D[10+ SELLs in 5min]
D --> E[π¨ FLASH_CRASH]
style E fill:#ff6b6b
Every trade undergoes comprehensive real-time risk analysis:
graph TB
A[Original Trade] --> B[Volume Analysis]
A --> C[Behavioral Analysis]
A --> D[Market Impact Analysis]
A --> E[Compliance Check]
B --> F[Risk Score Calculation]
C --> F
D --> F
E --> F
F --> G[Risk Level Assignment]
G --> H[RiskAnalyzedTrade]
style H fill:#c8e6c9
- Volume Analysis: Spike detection, percentile ranking, Z-scores
- Behavioral Analysis: Wash trading, spoofing, front-running patterns
- Market Impact: Liquidity consumption, price slippage, large orders
- Compliance: Sanctions, AML, KYC, geographic restrictions
- Trade Producer Dashboard:
http://localhost:8080/h2-console - Flink Web UI:
http://localhost:8081 - Risk Reporting Dashboard:
http://localhost:8082/dashboard - Elasticsearch Kibana:
http://localhost:5601
# Monitor risk alerts
kafka-console-consumer.sh --topic risk-alerts --bootstrap-server localhost:9092
# Monitor analyzed trades
kafka-console-consumer.sh --topic risk-analyzed-trades --bootstrap-server localhost:9092
# Check Elasticsearch data
curl http://localhost:9200/risk-analyzed-trades/_search?pretty
# Check Flink job status
curl http://localhost:8081/jobs# RocksDB State Backend
state.backend: rocksdb
state.backend.rocksdb: true
state.checkpoints.dir: s3://flink-checkpoints/risk-engine
state.backend.rocksdb.localdir: /tmp/flink/rocksdb
# Minio Checkpoint Configuration
s3.endpoint: http://minio:9000
s3.path.style.access: true
s3.credentials.provider: basic
s3.access.key: minioadmin
s3.secret.key: minioadmin# Kafka Configuration
kafka.bootstrap.servers=localhost:9092
kafka.topic.trades=crypto-trades
kafka.topic.alerts=risk-alerts
kafka.topic.analyzed.trades=risk-analyzed-trades
# Pattern Detection
volume.spike.window.minutes=2
volume.spike.threshold=1.5
wash.trading.window.minutes=1
wash.trading.quantity.tolerance=0.1
# Risk Thresholds
threshold.btc=500000.0
threshold.eth=250000.0
threshold.sol=100000.0producer:
mock:
enabled: true
rate-ms: 500
users: ["USER_001", "USER_002", "USER_003"]
symbols: ["BTC/USDT", "ETH/USDT", "SOL/USDT"]
exchanges: ["BINANCE", "COINBASE", "KRAKEN"]{
"tradeId": "unique-id",
"userId": "USER_001",
"symbol": "BTC/USDT",
"side": "BUY",
"quantity": 0.5,
"price": 45000.0,
"notional": 22500.0,
"timestamp": 1672531200000,
"exchange": "BINANCE",
"riskLevel": "LOW"
}{
"originalTrade": {...},
"riskScore": 0.75,
"finalRiskLevel": "HIGH",
"triggeredPatterns": ["VOLUME_SPIKE", "LARGE_ORDER"],
"volumeAnalysis": {...},
"behavioralAnalysis": {...},
"complianceFlags": ["TAX_REPORTING_REQUIRED"],
"riskMitigationActions": ["MANUAL_REVIEW_REQUIRED"]
}{
"alertId": "alert-123",
"patternType": "VOLUME_SPIKE",
"userId": "USER_001",
"severity": "HIGH",
"description": "User exhibited abnormal trading volume spike within short period",
"recommendedAction": "Temporarily limit user's trading limits and require manual review"
}{
"alertId": "alert-456",
"patternType": "WASH_TRADING",
"userId": "USER_002",
"severity": "CRITICAL",
"description": "Potential wash trading detected with rapid buy-sell cycles",
"recommendedAction": "Freeze account for investigation and report to compliance"
}apiVersion: apps/v1
kind: Deployment
metadata:
name: risk-engine
spec:
replicas: 3
template:
spec:
containers:
- name: risk-engine
image: crypto-risk-engine:1.0.0
env:
- name: KAFKA_BOOTSTRAP_SERVERS
value: "kafka-cluster:9092"
- name: SCHEMA_REGISTRY_URL
value: "http://schema-registry:8081"
- name: STATE_BACKEND_ROCKSDB
value: "true"
- name: MINIO_ENDPOINT
value: "http://minio:9000"- Flink Checkpointing: Minio S3 storage for state recovery with RocksDB backend
- Kafka Partitioning: Horizontal scaling across partitions
- Schema Registry: Avro schema evolution and compatibility
- Elasticsearch Cluster: Distributed search and analytics
# Run all tests
mvn test
# Run specific test suite
mvn test -Dtest=TradeRiskAnalyzerTest# Start test environment
docker-compose -f docker-compose.test.yml up
# Run integration tests
mvn verify -Pintegration-test# Generate high load
curl -X POST http://localhost:8080/api/admin/mock-trading/start?rateMs=100
# Monitor performance
curl http://localhost:8081/jobs/metrics
# Check Elasticsearch performance
curl http://localhost:9200/_cluster/health?pretty- Fork the repository
- Create feature branch:
git checkout -b feature/new-pattern - Commit changes:
git commit -am 'Add new risk pattern' - Push to branch:
git push origin feature/new-pattern - Submit pull request
- Follow Avro schema evolution best practices
- Include comprehensive unit tests
- Update documentation for new features
- Use descriptive commit messages
- Apache Flink Documentation
- Apache Kafka Documentation
- Avro Schema Evolution
- Complex Event Processing Patterns
- RocksDB State Backend
- Elasticsearch Kafka Connector
- Issues: GitHub Issues
- Documentation: Project Wiki
- Email: support@codedstreams.com
Nestor A. A.
Senior Software & Data Streaming Engineer
- π§ Email: nestorabiawuh@gmail.com
- πΌ LinkedIn: Nestor Abiangang
- π’ Role: Lead Developer - Crypto Risk Engine
- π§ Specialties: Backend Engineering, Real-time Stream Processing, Risk Management Systems, Distributed Systems
Built with β€οΈ by CodedStreams Engineering
Last Updated: October 2025