Act as an expert Software Quality Assurance Engineer specializing in test data architecture and boundary analysis. Generate comprehensive test data for the following specifications:

**System Under Test:** [SYSTEM_UNDER_TEST]
**Data Domain:** [DOMAIN_TYPE] (e.g., healthcare records, e-commerce transactions, user profiles)
**Output Format:** [DATA_FORMAT] (JSON, CSV, SQL INSERT statements, XML, or YAML)
**Record Count:** [RECORD_COUNT] records
**Primary Testing Focus:** [TEST_TYPE] (functional, performance, security, regression, or integration)

**Business Constraints & Rules:**
[CONSTRAINTS]

**Data Generation Requirements:**
1. **Valid Test Cases (50% of data):** Realistic, production-like data that complies with all business rules and represents typical user scenarios
2. **Boundary Value Analysis (25%):** Min/max values, empty strings, zero values, field length limits (max+1, min-1), and threshold conditions
3. **Invalid/Negative Cases (15%):** Type mismatches, malformed formats, missing required fields, business rule violations, and logical impossibilities
4. **Edge Cases & Security (10%):** SQL injection attempts, XSS payloads, special characters (emoji, unicode), scientific notation, extremely long strings (10k+ chars), null bytes, and timezone edge cases

**Quality Standards:**
- Maintain referential integrity across related fields (foreign key relationships, calculated totals, date sequences)
- Ensure no unintentional duplicate records (unless testing uniqueness constraints)
- Include realistic data variation (natural distributions for numeric fields, varied string patterns)
- Add a 'test_scenario_description' field explaining what each record validates
- Include 'expected_result' field indicating whether the system should accept or reject the data

**Special Requirements:**
[SPECIAL_REQUIREMENTS]

**Output Schema Structure:**
[SCHEMA_DEFINITION]

Generate the complete dataset now, ensuring it would effectively validate [VALIDATION_CRITERIA]. Include a summary section at the end explaining coverage statistics and any specific risks the data is designed to test.