🎯 Project Overview

SmartFinance is an enterprise-grade banking API platform designed for fintech companies and financial institutions. Built with Laravel 11 and powered by AWS DynamoDB, it provides secure, scalable financial services with real-time fraud detection and PCI DSS compliance.

🔒 Security-First Features

• PCI DSS Level 1 Compliance with end-to-end encryption
• Real-time fraud detection using machine learning algorithms
• Multi-factor authentication with biometric support
• Regulatory compliance (PSD2, GDPR, SOX)
• API rate limiting and DDoS protection
• Audit trail with immutable transaction logs
• KYC/AML automation with document verification

🛠️ Technical Architecture

API Layer (Laravel 11 + PHP 8.2)

// Secure Transaction Processing
class TransactionController extends Controller
{
    public function transfer(TransferRequest $request)
    {
        return DB::transaction(function () use ($request) {
            // Fraud detection check
            $riskScore = $this->fraudDetectionService
                ->analyze($request->validated());
                
            if ($riskScore > 0.8) {
                // Flag for manual review
                $this->flagTransactionForReview($request, $riskScore);
                throw new SuspiciousActivityException();
            }
            
            // Execute transfer with optimistic locking
            $fromAccount = Account::lockForUpdate()
                ->find($request->from_account_id);
                
            if ($fromAccount->balance < $request->amount) {
                throw new InsufficientFundsException();
            }
            
            // Atomic balance updates
            $fromAccount->decrement('balance', $request->amount);
            $toAccount = Account::find($request->to_account_id);
            $toAccount->increment('balance', $request->amount);
            
            // Create immutable transaction record
            $transaction = Transaction::create([
                'id' => Str::uuid(),
                'from_account_id' => $fromAccount->id,
                'to_account_id' => $toAccount->id,
                'amount' => $request->amount,
                'type' => 'transfer',
                'status' => 'completed',
                'reference' => $request->reference,
                'metadata' => $this->encryptMetadata($request->metadata),
                'risk_score' => $riskScore
            ]);
            
            // Real-time notification
            event(new TransactionCompleted($transaction));
            
            return new TransactionResource($transaction);
        });
    }
}

Database Schema (DynamoDB)

// Account Table Structure
{
  "TableName": "smartfinance-accounts",
  "KeySchema": [
    {
      "AttributeName": "account_id",
      "KeyType": "HASH"
    },
    {
      "AttributeName": "created_at",
      "KeyType": "RANGE"
    }
  ],
  "AttributeDefinitions": [
    {
      "AttributeName": "account_id",
      "AttributeType": "S"
    },
    {
      "AttributeName": "user_id",
      "AttributeType": "S"
    },
    {
      "AttributeName": "account_type",
      "AttributeType": "S"
    }
  ],
  "GlobalSecondaryIndexes": [
    {
      "IndexName": "UserAccountsIndex",
      "Keys": [
        {
          "AttributeName": "user_id",
          "KeyType": "HASH"
        }
      ]
    }
  ]
}

// Sample Account Record
{
  "account_id": "acc_1234567890",
  "user_id": "usr_abcdef1234",
  "account_type": "checking",
  "balance": {
    "N": "150000" // Stored in cents
  },
  "currency": "USD",
  "status": "active",
  "encryption_key_id": "arn:aws:kms:us-east-1:...",
  "created_at": "2024-10-10T10:00:00Z",
  "updated_at": "2024-10-10T15:30:00Z",
  "metadata": {
    "account_name": "Main Checking",
    "overdraft_limit": 50000,
    "interest_rate": 0.0125
  }
}

Fraud Detection Engine

// ML-powered Fraud Detection Service
class FraudDetectionService
{
    public function analyze(array $transactionData): float
    {
        $features = $this->extractFeatures($transactionData);
        
        // Real-time scoring using trained model
        $riskFactors = [
            'velocity_score' => $this->calculateVelocityRisk($features),
            'amount_score' => $this->calculateAmountRisk($features),
            'location_score' => $this->calculateLocationRisk($features),
            'device_score' => $this->calculateDeviceRisk($features),
            'behavior_score' => $this->calculateBehaviorRisk($features)
        ];
        
        // Weighted risk calculation
        $totalRisk = array_sum([
            $riskFactors['velocity_score'] * 0.3,
            $riskFactors['amount_score'] * 0.25,
            $riskFactors['location_score'] * 0.2,
            $riskFactors['device_score'] * 0.15,
            $riskFactors['behavior_score'] * 0.1
        ]);
        
        // Log for model training
        $this->logRiskAssessment($transactionData, $riskFactors, $totalRisk);
        
        return min($totalRisk, 1.0);
    }
    
    private function calculateVelocityRisk(array $features): float
    {
        // Check transaction frequency patterns
        $recentTransactions = $this->getRecentTransactions(
            $features['user_id'], 
            now()->subMinutes(30)
        );
        
        if (count($recentTransactions) > 10) {
            return 0.9; // High velocity risk
        }
        
        return count($recentTransactions) * 0.05;
    }
}

🔐 Security Implementation

Encryption & Key Management

// AWS KMS Integration for Data Encryption
class EncryptionService
{
    private $kmsClient;
    private $keyId;
    
    public function encryptSensitiveData(string $data): array
    {
        $result = $this->kmsClient->encrypt([
            'KeyId' => $this->keyId,
            'Plaintext' => $data,
            'EncryptionContext' => [
                'application' => 'smartfinance',
                'data_type' => 'pii',
                'timestamp' => now()->toISOString()
            ]
        ]);
        
        return [
            'encrypted_data' => base64_encode($result['CiphertextBlob']),
            'key_id' => $result['KeyId'],
            'encryption_algorithm' => 'AES-256-GCM'
        ];
    }
    
    public function decryptSensitiveData(string $encryptedData): string
    {
        $result = $this->kmsClient->decrypt([
            'CiphertextBlob' => base64_decode($encryptedData)
        ]);
        
        return $result['Plaintext'];
    }
}

API Security Middleware

// Rate limiting and API security
class BankingApiMiddleware
{
    public function handle(Request $request, Closure $next)
    {
        // API Key validation
        $apiKey = $request->header('X-API-Key');
        if (!$this->validateApiKey($apiKey)) {
            return response()->json(['error' => 'Invalid API key'], 401);
        }
        
        // Rate limiting by client
        $rateLimiter = RateLimiter::for('banking-api', function (Request $request) {
            return Limit::perMinute(100)->by($request->header('X-API-Key'));
        });
        
        if ($rateLimiter->tooManyAttempts()) {
            return response()->json(['error' => 'Rate limit exceeded'], 429);
        }
        
        // IP whitelist check for sensitive operations
        if ($this->isSensitiveOperation($request) && !$this->isWhitelistedIp($request->ip())) {
            $this->logSuspiciousActivity($request);
            return response()->json(['error' => 'Unauthorized IP'], 403);
        }
        
        return $next($request);
    }
}

📊 Performance & Scalability

Metrics

• API Response Time: 50ms average (P99: 150ms)
• Throughput: 10,000 transactions per second
• Availability: 99.99% uptime (4 9’s)
• Data Consistency: Strong consistency for financial data
• Fraud Detection: < 100ms real-time analysis

AWS Architecture

# Infrastructure as Code (CloudFormation)
Resources:
  SmartFinanceAPI:
    Type: AWS::ECS::Service
    Properties:
      Cluster: !Ref ECSCluster
      TaskDefinition: !Ref TaskDefinition
      DesiredCount: 10
      LoadBalancers:
        - ContainerName: smartfinance-api
          ContainerPort: 80
          TargetGroupArn: !Ref ALBTargetGroup
          
  DynamoDBTable:
    Type: AWS::DynamoDB::Table
    Properties:
      TableName: smartfinance-transactions
      BillingMode: ON_DEMAND
      PointInTimeRecoverySpecification:
        PointInTimeRecoveryEnabled: true
      SSESpecification:
        SSEEnabled: true
        KMSMasterKeyId: !Ref KMSKey

🚧 Compliance & Auditing

Regulatory Compliance

• PCI DSS Level 1: Credit card data handling
• SOX Compliance: Financial reporting controls
• GDPR: European data protection
• PSD2: Open banking standards
• AML/KYC: Anti-money laundering

Audit Trail

// Immutable audit logging
class AuditLogger
{
    public function logTransaction(Transaction $transaction, User $user)
    {
        $auditRecord = [
            'event_id' => Str::uuid(),
            'event_type' => 'transaction_created',
            'user_id' => $user->id,
            'transaction_id' => $transaction->id,
            'amount' => $transaction->amount,
            'timestamp' => now()->toISOString(),
            'ip_address' => request()->ip(),
            'user_agent' => request()->userAgent(),
            'checksum' => hash('sha256', json_encode($transaction->toArray()))
        ];
        
        // Store in immutable log
        DynamoDbClient::putItem([
            'TableName' => 'audit_logs',
            'Item' => $auditRecord
        ]);
        
        // Also send to CloudWatch for monitoring
        Log::channel('audit')->info('Transaction audit', $auditRecord);
    }
}

🔮 Future Enhancements

• Open Banking APIs (PSD2 compliance)
• Cryptocurrency support with regulatory compliance
• AI-powered financial insights and recommendations
• Biometric authentication integration
• Blockchain audit trail for enhanced transparency

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Technologies: Laravel 11, PHP 8.2, AWS DynamoDB, KMS, ECS, CloudWatch
Compliance: PCI DSS Level 1, SOX, GDPR, PSD2
Documentation: API Reference

SmartFinance showcases my expertise in building secure, compliant financial systems with enterprise-grade architecture and real-time fraud prevention.