What problem does it solve? Scaling a Kailash application from a single-process SQLite setup to a multi-worker PostgreSQL or MySQL deployment normally requires rewriting persistence, queueing, and concurrency logic. This Skill encodes the progressive infrastructure model so the same workflow code runs at Level 0 (SQLite), Level 1 (shared database), and Level 2 (multi-worker with task queue) using only environment variables. ## Core Features & Use Cases - Progressive Infrastructure Model: Scale from Level 0 to Level 2 via KAILASH_DATABASE_URL and KAILASH_QUEUE_URL, with StoreFactory auto-detecting the correct store backends. - Dialect-Portable SQL: Write queries once with canonical ? placeholders and let QueryDialect translate them for PostgreSQL, MySQL 8.0+, and SQLite, including upsert, insert-ignore, and JSON extraction. - Task Queue and Worker Registry: Distribute work with SQLTaskQueue using FOR UPDATE SKIP LOCKED, monitor workers via heartbeats, and reap dead workers with automatic task requeue. - Idempotent Execution: Guarantee exactly-once workflow execution with IdempotentExecutor using the atomic claim-execute-store pattern and TTL expiry. - Use Case: A team running ETL workflows locally on SQLite needs to move to production PostgreSQL with multiple workers. They set two environment variables, and StoreFactory, SQLTaskQueue, and IdempotentExecutor handle shared state, distributed dequeue, and duplicate-execution prevention without code changes. ## Quick Start Ask the AI to configure the Kailash StoreFactory with KAILASH_DATABASE_URL pointing to your PostgreSQL database and show how to enqueue and dequeue tasks with SQLTaskQueue.