# ADR 0001: Synchronous External Calls For MVP

## Status

Accepted

## Context

The MVP relies on OTP delivery, booking notifications, and payment gateway calls. Introducing a task queue (Celery/RQ) would add infrastructure (Redis, workers, retries) and operational complexity that is not required for the early launch.

## Decision

For the MVP, OTP sends, booking notifications, and payment gateway calls run synchronously in the request/response path with strict timeouts. A task queue will be revisited when traffic grows or operational needs change.

## Consequences

- Faster initial delivery with fewer moving parts.
- Increased latency risk on endpoints that call external providers.
- Failures are immediately visible to clients and logged for support.

## Alternatives Considered

- Celery + Redis for all external calls: rejected for MVP due to infra overhead.
- Hybrid async for notifications only: rejected to keep the execution model consistent.

## Related

- `docs/architecture.md`