# Epic #65: Batch Processing & Workflows

**Priority**: High - Required for production business use
**Phase**: 2 (Automation & Scale)
**Epic Owner**: Requirements Engineering Agent
**Created**: 2025-10-02

## Epic Overview

Enable enterprise-scale document automation through comprehensive batch processing and workflow orchestration capabilities. Transform MarkiTect from single-document operations to production-ready business process automation supporting hundreds or thousands of documents.

## Business Value

- **Mass Generation**: Process customer databases to generate hundreds of invoices/reports
- **Automated Workflows**: Orchestrate complex document pipelines with validation steps
- **Enterprise Scale**: Support business operations requiring high-volume document processing
- **Process Automation**: Replace manual document generation with automated workflows

## Epic Acceptance Criteria

- [ ] Process 1000+ documents in single batch operation with progress tracking
- [ ] Generate invoices from customer database with error handling and reporting
- [ ] Orchestrate multi-step workflows (generate → validate → export → notify)
- [ ] Support multiple data source formats (CSV, JSON, Database, API)
- [ ] Provide comprehensive batch operation reporting and error management
- [ ] Scale to enterprise requirements with parallel processing

## Architecture Integration

### **Existing Integration Points**
- **Template Engine**: Use templates from Epic #64 for batch generation
- **CLI Commands**: Extend with batch-oriented commands
- **Database**: Store batch jobs, progress, and results
- **Quality Assurance**: Integrate batch validation with QA workflows
- **Error Handling**: Comprehensive error tracking and recovery

### **New Domain Models Required**
- `BatchJob`: Batch operation definition and tracking
- `WorkflowEngine`: Multi-step process orchestration
- `DataSource`: External data source abstraction
- `BatchProgress`: Progress tracking and reporting
- `BatchResult`: Operation results and error reporting

## Decomposed Issues

### **Issue #65.1: Batch Job Engine Foundation**
**Priority**: Critical | **Effort**: Large | **Dependencies**: Epic #64

**Description**: Implement core batch processing engine with job management and progress tracking

**Acceptance Criteria**:
- [ ] Define and execute batch jobs with progress tracking
- [ ] Support parallel processing with configurable worker threads
- [ ] Job queuing and scheduling capabilities
- [ ] Progress reporting with estimated completion times
- [ ] Error recovery and retry mechanisms
- [ ] CLI command: `markitect batch create --template invoice.md --data customers.csv`

**Technical Requirements**:
- Job queue management with persistence
- Worker thread pool for parallel processing
- Progress tracking with real-time updates
- Error handling with retry logic and fallback strategies

---

### **Issue #65.2: Multi-Source Data Integration**
**Priority**: Critical | **Effort**: Large | **Dependencies**: #65.1

**Description**: Support multiple data source formats and external system integration

**Acceptance Criteria**:
- [ ] CSV file processing with column mapping
- [ ] JSON data source support with nested object handling
- [ ] Database connectivity (SQLite, PostgreSQL, MySQL)
- [ ] REST API data source integration
- [ ] Data transformation and mapping capabilities
- [ ] Error handling for invalid or missing data

**Technical Requirements**:
- Data source adapter architecture with plugin system
- Schema validation and data type conversion
- Connection pooling and resource management
- Data transformation pipeline with filtering and mapping

---

### **Issue #65.3: Workflow Orchestration Engine**
**Priority**: High | **Effort**: Large | **Dependencies**: #65.1, #65.2

**Description**: Implement multi-step workflow orchestration for complex business processes

**Acceptance Criteria**:
- [ ] Define workflows with multiple steps and conditions
- [ ] Support workflow branching based on data or results
- [ ] Step-by-step execution with intermediate validation
- [ ] Workflow templates for common business processes
- [ ] Error handling and workflow recovery mechanisms
- [ ] Workflow visualization and monitoring

**Technical Requirements**:
- Workflow definition language (YAML/JSON)
- Step execution engine with context management
- Conditional execution and branching logic
- Workflow state persistence and recovery

---

### **Issue #65.4: Batch Validation & Quality Control**
**Priority**: High | **Effort**: Medium | **Dependencies**: #65.1, Epic #64

**Description**: Implement comprehensive validation and quality control for batch operations

**Acceptance Criteria**:
- [ ] Pre-batch validation of templates and data sources
- [ ] Real-time validation during batch processing
- [ ] Quality gates with configurable validation rules
- [ ] Integration with existing QA checklist system
- [ ] Validation reporting with detailed error descriptions
- [ ] Automatic retry for validation failures

**Technical Requirements**:
- Validation rule engine with configurable rules
- Integration with existing template and schema validation
- Quality metrics collection and reporting
- Error categorization and remediation suggestions

---

### **Issue #65.5: Batch Monitoring & Reporting**
**Priority**: Medium | **Effort**: Medium | **Dependencies**: #65.1

**Description**: Provide comprehensive monitoring and reporting for batch operations

**Acceptance Criteria**:
- [ ] Real-time batch progress monitoring with web dashboard
- [ ] Detailed batch operation reports with success/failure statistics
- [ ] Performance metrics and optimization recommendations
- [ ] Batch history with searchable logs
- [ ] Email/webhook notifications for batch completion/failure
- [ ] Export batch reports in multiple formats

**Technical Requirements**:
- Monitoring dashboard with real-time updates
- Comprehensive logging and audit trail
- Report generation with customizable formats
- Notification system with multiple delivery methods

---

### **Issue #65.6: Enterprise Integration & APIs**
**Priority**: Medium | **Effort**: Medium | **Dependencies**: #65.1, #65.2

**Description**: Provide enterprise integration capabilities and REST API access

**Acceptance Criteria**:
- [ ] REST API for batch job creation and monitoring
- [ ] Webhook integration for external system notifications
- [ ] Enterprise authentication and authorization
- [ ] API rate limiting and quota management
- [ ] Integration with existing enterprise systems (ERP, CRM)
- [ ] SDK/client libraries for common languages

**Technical Requirements**:
- RESTful API design with OpenAPI specification
- Authentication system with JWT/OAuth support
- Rate limiting and quota enforcement
- Client SDK generation and documentation

---

### **Issue #65.7: Performance Optimization & Scaling**
**Priority**: High | **Effort**: Medium | **Dependencies**: All above

**Description**: Optimize performance for enterprise-scale batch operations

**Acceptance Criteria**:
- [ ] Process 1000+ documents in under 5 minutes
- [ ] Memory optimization for large batch operations
- [ ] Horizontal scaling with multiple worker instances
- [ ] Caching strategies for improved performance
- [ ] Resource monitoring and automatic scaling
- [ ] Performance benchmarking and optimization tools

**Technical Requirements**:
- Performance profiling and optimization
- Caching layer with intelligent cache invalidation
- Horizontal scaling architecture
- Resource monitoring and alerting

## Epic Dependencies

### **External Dependencies**
- Epic #64 (Template & Calculation Engine) - Required for template-based batch generation
- Database systems for data source integration
- External APIs and systems for enterprise integration

### **Internal Dependencies**
- Existing CLI command architecture
- Current validation and QA systems
- Database and storage infrastructure
- Error handling and logging frameworks

## Success Metrics

### **Technical Metrics**
- Batch processing speed: 1000+ documents in <5 minutes
- Memory efficiency: Linear memory usage with batch size
- Error handling: <1% unrecoverable failures
- Concurrency: Support 10+ parallel batch jobs

### **Business Metrics**
- Enterprise adoption: Support for major business use cases
- Workflow automation: 5+ predefined business workflow templates
- Integration success: Connect to common enterprise systems
- User satisfaction: Comprehensive monitoring and error reporting

## Implementation Timeline

**Phase 1** (Issues #65.1, #65.2): Core batch engine and data integration (3-4 weeks)
**Phase 2** (Issues #65.3, #65.4): Workflow orchestration and validation (2-3 weeks)
**Phase 3** (Issues #65.5, #65.6, #65.7): Monitoring, APIs, and optimization (2-3 weeks)

**Total Epic Duration**: 7-10 weeks

## Risk Mitigation

- **Performance Risk**: Implement caching and optimization from the start
- **Scalability Risk**: Design for horizontal scaling from foundation
- **Integration Risk**: Start with common data sources, expand incrementally
- **Complexity Risk**: Begin with simple workflows, add advanced features iteratively