Architected a data pipeline processing 20+ transaction types (invoices, bank mutations, stock adjustments, journal entries) — queue-based execution, row-level validation, async error reporting. The platform's most critical system.

Shipped BCA + Mandiri + OCBC banking integration: migrated from scraping to BCA SNAP API with OAuth2. Automated daily mutation sync, duplicate detection, idle-account auto-deactivation.

Unified 6 marketplace platforms (Shopee, Tokopedia, Lazada, TikTok Shop, Bukalapak, Olsera) into one normalized import pipeline — per-platform discount, coin, voucher, and shipping logic.

Owned the Shopify Embedded App end-to-end — OAuth2 install flow, App Bridge compliance, webhook-driven sync via GraphQL Admin API, multi-step tenant claim flow. Passed Shopify app review.

Cut API response time 40% — bulk upserts replacing updateOrCreate, rewritten caching layers, targeted MySQL indexes on the highest-traffic endpoints.

Cut background processing 70% — per-tenant queue isolation with customizable queue names, priority-based routing, automatic retry on SQS.

Eliminated double-payment bugs with atomic locks on invoice, purchase, and expense flows. Zero race-condition incidents since deployment.

Built multi-currency engine — 3 automated rate crawlers (Bank Indonesia, Kurs Pajak, Fixer.io), historical backfill from 2018, auto-applied across all transaction types.

Cut CI/CD from 40 min to 15 min — concurrent test stages, PHP 8 Docker images, RAM-disk runners, optimized DB seeding.

Shipped Coretax XML + E-Faktur CSV exports for DJP tax compliance — DPP/PPN calculation, rounding edge cases, bulk upload. Thousands of businesses filing automatically.

Built WooCommerce sync plugin from scratch — orders, shipping, tax mapping, coupons, inventory sync. Retry logic on webhooks. Full test coverage.

Led PHP 7.4 → 8.x migration across the entire codebase. Updated Docker images, CI configs, resolved breaking changes.

Deployed centralized observability — tenant-aware Sentry tagging, structured job logs with daily rotation, Kibana dashboards for production debugging.