Phantoms — AI Content Automation Engine
A queue-driven NestJS backend that takes short-form video from script to multi-platform publish — hardened with circuit breakers, retries, and dead-letter handling.
The problem
Short-form video has a long tail of steps — generate a script, render it, get it approved, reformat and publish it across platforms, then read back the performance. Done by hand it's slow; done naively in code it's fragile, because every step depends on an external service (an LLM, a render API, a social platform) that will eventually rate-limit, time out, or fail.
The brief was a backend that runs this pipeline end-to-end and stays up when its dependencies don't.
The architecture
A NestJS service models the pipeline as a set of BullMQ queues over Redis, with PostgreSQL holding state for every asset as it moves through the stages.
Failure handling is the feature
Each external call sits behind a circuit breaker — when a provider starts failing, the breaker trips and the pipeline stops hammering it instead of burning retries. Jobs that exhaust their retries land in a dead-letter queue for inspection rather than vanishing, so nothing is silently lost and a single bad asset never stalls the whole run.
Stage isolation
Every stage is its own queue with its own concurrency and rate limits. Rendering (slow, quota-limited) can't starve publishing; a spike in script generation can't overrun the render API. State in PostgreSQL means a worker can crash mid-pipeline and the asset resumes from its last completed stage.
The model call is a few lines. The engineering is everything around it — idempotent stage transitions, breakers on every integration, and a dead-letter path that turns "it broke at 3am" into a queue you can drain in the morning.
Outcomes
What this taught me
When a backend orchestrates other people's APIs, resilience is the product. Breakers, retries, and a dead-letter queue were what made an automation people could actually leave running unattended.
Building something similar?
Send a quick note — happy to compare notes on the architecture.