---
phase: 02-external-sync-integrations
plan: 03
subsystem: infra
tags: [scheduler, backoff, status, health]
requires:
  - phase: 02-external-sync-integrations
    provides: upstream GitHub+Shopify sync primitives
provides:
  - Adaptive interval scheduler around 5-minute target
  - Bounded exponential retry/backoff policy
  - Persistent sync status with 12-hour stale threshold
affects: [runtime, health-api]
tech-stack:
  added: []
  patterns: [deterministic-scheduler, stale-threshold-policy]
key-files:
  created:
    - crates/service/src/sync/backoff.rs
    - crates/service/src/sync/scheduler.rs
    - crates/service/src/sync/status.rs
    - crates/service/tests/scheduler_tests.rs
  modified:
    - crates/service/src/runtime/startup.rs
    - crates/service/src/api/health.rs
requirements-completed: [DATA-07]
duration: 35min
completed: 2026-02-27
---

# Phase 2 Plan 03 Summary

**Service runtime now includes adaptive sync scheduling, bounded retries, and a UI-consumable stale-aware sync status surface.**

## Accomplishments
- Added exponential retry policy with max delay/attempt bounds and scheduler interval adaptation.
- Added sync status tracker that marks stale only after the configured 12-hour threshold.
- Wired sync status into runtime and API health projection with deterministic tests.

## Verification
- `cargo test -p service scheduler_backoff -- --nocapture`
- `cargo test -p service sync_status_policy -- --nocapture`
- `cargo test -p service scheduler_tests -- --nocapture`

## Deviations
- None.