E-Commerce Peak Checkout Load Test Generator

Role: Senior Quality Engineering Specialist with 12+ years of expertise in retail e-commerce scalability and performance stress testing.

Context

• Target Platform Architecture: {{ecommerce_platform}}
• Target Concurrency Volume: {{target_concurrency}}
• Critical Checkout Route: {{checkout_endpoint}}
• Active Test Stock Keeping Units: {{inventory_skus}}
• Payment Simulation Provider: {{payment_gateway_mock}}
• Latency SLA Threshold: {{p95_latency_threshold}}

Task

Author a fully executable k6 load test automation script that simulates realistic customer checkout funnels, validates concurrent stock reservations, and isolates latency bottlenecks across the {{ecommerce_platform}} infrastructure to ensure platform stability under {{target_concurrency}}.

Method

1. Define stage-based load ramp-up, steady-state peak, and ramp-down execution profiles aligned with {{target_concurrency}}.
2. Configure explicit threshold assertions enforcing {{p95_latency_threshold}} for HTTP response times and a sub-1% transaction error rate.
3. Implement parameterized user persona data pools utilizing {{inventory_skus}} to simulate dynamic cart addition and SKU contention.
4. Script multi-step transaction flows spanning catalogue search, cart addition, stock lock acquisition, and checkout payload dispatch to {{checkout_endpoint}}.
5. Integrate mock header authentication and payload payload verification targeting {{payment_gateway_mock}} without triggering production billing loops.
6. Embed custom metric counters and trend tracking for stock collision errors, session drops, and payment gateway round-trip latency.
7. Implement intelligent retry mechanics with exponential backoff on transient network failures while logging unrecoverable server errors.
8. Structure modular tear-down logic to release dangling inventory reservations created during execution.

Constraints

• Scripts MUST be written in syntactically valid modern JavaScript for k6 runtime execution.
• Scripts MUST NOT hardcode plaintext payment tokens, private keys, or static customer sessions.
• Handlers MUST explicitly verify HTTP 200/201 response status codes before proceeding through multi-step checkout gates.
• Custom metrics MUST track distinct tag boundaries for inventory lock versus payment settlement phases.

Output format

Executable k6 JavaScript test script formatted inside a single code block, followed by:

• Environment variable configuration guide (table of key, type, default, purpose)
• Scenario breakdown detailing virtual user ramp-up schedules and duration
• Error handling table listing caught status codes and alert conditions Total response length must remain between 450 and 850 lines of combined code and technical documentation.

Self-review

• Confirm all 6 context variables ({{ecommerce_platform}}, {{target_concurrency}}, {{checkout_endpoint}}, {{inventory_skus}}, {{payment_gateway_mock}}, {{p95_latency_threshold}}) are actively referenced in script logic.
• Verify syntax avoids non-k6-compatible Node.js standard library imports.
• Check that threshold boundaries strictly reflect {{p95_latency_threshold}}.