Stratos Wallet
A production-grade fintech wallet frontend built around ledger-first correctness and real-time resilience.
Overview
Stratos is a production-grade fintech wallet frontend: a deliberate deep-dive into the hard parts of money software on the client: correctness, real-time state, and resilience under failure. It pairs a ledger-first data model with a custom real-time reliability protocol and a chaos harness that proves the UI degrades gracefully instead of only working on the happy path. The design decisions behind it are documented in a companion Docusaurus site that lives in the same monorepo (see Stratos Docs).
Features
Ledger-first data model: an append-only ledger with balances derived, never stored
Contract-first codegen with optimistic mutations, cache-snapshot rollback, and idempotency keys on every money-moving operation
Custom WebSocket reliability protocol: sequence numbers with gap detection, dedup, missed-event replay on reconnect, backoff with jitter
Chaos / fault-injection harness with 18 failure presets to verify graceful degradation
Key Engineering Decisions
Chose event-sourced, derived balances over stored balances: no drift, with a documented snapshot scaling path
Built at-least-once real-time delivery correct by construction: dedup by event ID, replay missed events on reconnect
Made money operations safe against double-submits with idempotency keys and rollback snapshots
Made resilience testable by injecting 18 failure modes instead of trusting the happy path
Tech Stack
Project Links
Project Info
Author
Etinosa Ogbevoen
Status
active
Category
Fintech