Lumbung
- Origin
- Our own product
- Year
- 2026
- Category
- Consumer
- Status
- In active development
- Stack
- Flutter, Dart, Bloc, Melos, Go, Echo, PostgreSQL, River, Nuxt 4, Tailwind v4
A personal and shared finance app that works fully without a signal. Lumbung pairs the logging speed of a money manager with shared spaces for couples, families, housemates and groups. Our own product, in active development and currently taking waitlist sign-ups.
Visit product →№ 01 / The Challenge
The Challenge
Money is rarely managed alone. Couples split the household bills, families keep one budget, housemates chip in for electricity. Most trackers are built for one person, or need the internet before they can be shared. An entry written somewhere with no signal must not be lost either. And financial data is sensitive: people need to know it is encrypted and can be exported at any time.
№ 02 / What We Built
What We Built
Banua Coder is building Lumbung as an offline-first finance platform. The Flutter client writes every entry to a local database first, then syncs it per entry across devices when the signal returns. One Workspace concept holds both personal and shared ledgers, with roles (owner, admin, member, viewer), and every entry shows who added it. A Go backend handles sync, accounts and subscriptions, while the marketing site and admin console are built separately.
№ 03 / Impact & Results
Impact & Results
- 01 In active, open development: the site is live with a waitlist, the app is not released yet
- 02 Core work done so far: offline-first logging, cross-device sync, and shared spaces with roles
- 03 Features such as split bills, budgets and import from an old tracker are still on the roadmap and marked that way on the site
- 04 One product, three parts we build ourselves: the Flutter app, the Go backend and the marketing site
Video
Watch it in motion. Press play; nothing loads until you do.
Product promo · 9:16 · 72 s
Lumbung promo film
№ 05 / Project detail
Context
A lumbung is the Indonesian communal rice granary raised on stilts, where a household or village stores its harvest together. The name fits because the product is about storing together: one place for personal money, money shared by two, and each person’s share of it. It is a working name and not final.
This is our own product, not client work. It is in active development: the site is live and takes waitlist sign-ups, but the app cannot be downloaded yet. This page only describes what exists and marks what does not.
What we are building
- Flutter client: a Melos workspace with clean architecture and Bloc/Cubit. Every entry is written to an encrypted local database first, so the app stays fully usable with no network.
- Shared spaces: one Workspace concept for personal, couple, family, housemate, group trip and small business use. People are invited with a role, not by sharing a password.
- Sync: changes sync per entry across devices with automatic conflict merge, not as a single whole-file backup.
- Precise money: amounts are stored as minor units, a currency code and a scale, so rupiah, yen and Kuwaiti dinar are not forced into one two-decimal rule.
- Go backend: a modular monolith with Echo, pgx, River for background jobs, and PostgreSQL. It handles sync, accounts and billing.
- Marketing site and admin console: a bilingual site with a waitlist (Nuxt 4, Tailwind v4), plus an admin console and a status page.
Engineering notes
Offline-first here is not a fallback mode. The app writes to local storage first and the network only delivers the result. That means sync has to merge two devices that both changed data while disconnected, and that is where most of the backend work goes.
The other principles we hold: calm language, with no gamification and no guilt; data encrypted on the device; no scraping of users’ bank accounts; and data that can be exported at any time.
Where it stands
Lumbung is not released and has no users yet. That is why this page carries no user numbers, testimonials or app store links, and why the prices on the site are still plans. Follow progress on the Lumbung site.
Tech Stack
- Flutter
- Dart
- Bloc
- Melos
- Go
- Echo
- PostgreSQL
- River
- Nuxt 4
- Tailwind v4
Links
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