Icons/clock square DEC 2020 - MAR 2021
Icons/leader speech TECHNICAL LEAD
Icons/department 3 ENGINEERS

Payment Processing System

Build a secure, reliable payment processing system that handles multiple payment methods, ensures regulatory compliance, and provides seamless donation experience while preventing fraud

99.9%
SUCCESS RATE

Transaction completion

0.1%
FRAUD RATE

Below industry average

500ms
PROCESSING TIME

Average transaction speed

100%
COMPLIANCE

PCI DSS standards met

Icons/tools TECHNOLOGIES
Ruby on Rails Stripe PostgreSQL Redis Sidekiq AWS KMS Elasticsearch NewRelic
APPROACH & PROCESS

Strategic Implementation

The Payment Processing System was developed with a focus on security and reliability:

1. Security Implementation
- Implemented PCI DSS compliance
- Developed encryption system
- Created access controls
- Built audit logging
- Designed security monitoring

2. Payment Processing
- Implemented Stripe integration
- Developed payment methods
- Created retry logic
- Built reconciliation system
- Designed refund handling

3. Fraud Prevention
- Implemented risk scoring
- Developed fraud detection
- Created validation rules
- Built monitoring system
- Designed manual review tools

4. Reconciliation System
- Implemented automated matching
- Developed error handling
- Created reporting system
- Built notification system
- Designed investigation tools

IMPLEMENTATION

Solution Design

The implementation focused on creating a secure and efficient payment system:

1. Core Features
- Payment Processing
* Multiple payment methods
* Recurring donations
* Payment validation
* Error handling
* Receipt generation
* Refund processing
* Dispute management

- Security Measures
* Data encryption
* Token management
* Access control
* Audit logging
* Compliance monitoring
* Sensitive data handling
* Security alerts

- Fraud Prevention
* Risk assessment
* Pattern detection
* Validation rules
* Manual review
* Block management
* Investigation tools
* Report generation

2. Technical Implementation
- Transaction Pipeline
* Payment validation
* Processing logic
* Error handling
* Status tracking
* Notification system
* Receipt generation
* Reconciliation

- Monitoring System
* Transaction monitoring
* Performance tracking
* Error detection
* Security alerts
* Compliance checking
* System health
* Resource usage

CHALLENGES & SOLUTIONS

Problem Solving

Key challenges in developing the payment system included:

1. PCI Compliance
Challenge: Meeting strict PCI DSS requirements.
Solution:
- Implemented tokenization
- Developed secure infrastructure
- Created audit system
- Built compliance monitoring
- Designed security controls

2. Fraud Prevention
Challenge: Detecting and preventing fraudulent transactions.
Solution:
- Implemented risk scoring
- Developed pattern detection
- Created validation rules
- Built monitoring system
- Designed review process

3. System Reliability
Challenge: Ensuring consistent payment processing.
Solution:
- Implemented retry logic
- Developed fallback systems
- Created monitoring tools
- Built redundancy
- Designed recovery procedures

4. Reconciliation
Challenge: Automating payment reconciliation.
Solution:
- Implemented matching algorithms
- Developed error detection
- Created investigation tools
- Built reporting system
- Designed manual controls

IMPACT & RESULTS

Business Value

The Payment Processing System achieved significant results:

1. Transaction Success
- 99.9% successful processing
- 0.1% fraud rate
- 500ms average processing time
- 100% PCI compliance
- Zero security incidents

2. System Performance
- Real-time processing
- Automated reconciliation
- Efficient error handling
- Comprehensive monitoring
- Reliable operations

3. Business Impact
- Increased donor confidence
- Reduced operational costs
- Improved fraud prevention
- Enhanced reporting
- Better compliance

4. Operational Efficiency
- Automated processes
- Reduced manual review
- Faster reconciliation
- Better error handling
- Improved monitoring

VISUAL DOCUMENTATION

System Overview

PA

Secure payment processing workflow and components

SF

Security measures and compliance controls

FP

Risk assessment and fraud detection system

RF

Payment reconciliation and reporting process

MS

Transaction and security monitoring