From a phone app to a cluster

Ivy Wallet+ started as an open-source money manager for Android but faced the owner's decision to archive it. The author forked it, adding features like photo and audio attachments, transaction location, balance at day, SMS auto-fill, and a reports filter. The data captured by the phone app inspired the idea of creating a read-only desktop dashboard to analyze the backups stored on Google Drive.

The first blueprint for the dashboard was ambitious, incorporating features like a Kotlin sync client, Go sync API, Postgres database, Redis cache, Istio service mesh, GitOps, canaries, and an observability stack. However, a critique from Claude Code revealed that the proposal would take about 18 months to build and had several flaws, such as using Redis as both cache and queue, breaking read-your-writes with read replicas, and lacking an identity layer.

The author then made significant changes, cutting the project down to three stateless TypeScript services, Kubernetes for delivery, and five architecture decision records (ADRs) outlining the decisions made. These decisions included using stateless services, removing the database, limiting Google Drive access, ensuring Kubernetes is the only delivery path, and using ECB exchange rates as the default source.

The goal was to build, secure, test, and deliver the product like a production software, with the personal dashboard being the final point. The series of posts will cover the dashboard's features and the transition from a local k3d cluster to three machines at home, with each issue addressing the challenges faced during the process.