What was built
DESIGO® sells milk from indigenous Indian cows in returnable glass bottles. The promise is traceability — so the software has to answer, from a single bottle’s QR code, which farms’ milk is inside and in what proportion, and survive being audited on that answer.
DESIGO® Fleet — delivery. A rider app and admin console that replaced WhatsApp-and-Excel delivery operations.
- Foreground-service GPS duty tracking with a watchdog, and offline map tiles for routes.
- QR bottle custody with check-digit IDs, and an offline scan queue that replays on reconnect.
- Photo proof of delivery stored in Cloudflare R2 behind a Worker that holds no secret — callers authorise with their own Firebase token.
RTCOM® Operations — farm and plant. An Android field app that records collection, chilling, barrels, dispatch, plant receipt, batches and filling — a mass-balance traceability ledger rather than a CRUD app.
- Encrypted offline outbox (SQLCipher), verified on hardware.
- One shared Firebase project with Fleet, because the glass bottle is the same physical object in both apps; security rules are merged and tested so neither app can break the other.
- Composition and mass-balance kernels that compute what proportion of each farm’s milk ends up in each bottle.
RTCOM ERP — the business system of record. Farm collection, plant, inventory, customers, delivery, finance and workforce on one platform; it reads the field apps through a controlled integration layer and never writes to them.
- Business rules live in the database: row-level security for reads, command functions for writes.
- Exact quantities stored as integers (grams, units, paise); append-only ledgers with derived balances.
- Idempotency keys, a concurrency harness and fault injection for atomicity; an undecided policy refuses with a named reason instead of guessing.