Solo dev shares architecture behind AI line art SaaS built with Next.js and Stripe

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An independent developer has launched ailineart.com, a bootstrapped AI-powered tool that converts photos and text prompts into line art styles such as sketch, pencil, and watercolor. The platform was built using Next.js for the frontend, a PostgreSQL-backed worker queue for handling long-running AI jobs, and Stripe for managing subscriptions and per-generation credit purchases. To avoid serverless timeout failures and accidental double-billing, the developer routed all AI generation tasks through a background worker process rather than handling them directly within web requests. A PostgreSQL jobs table with atomic row-locking via SELECT FOR UPDATE SKIP LOCKED ensures multiple workers can run concurrently without conflicts. The developer also implemented an automatic credit refund mechanism triggered whenever a generation job fails, ensuring users are never silently charged for unsuccessful outputs.

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