Repo layout

Bun workspaces monorepo. Apps split into two top-level categories.

`apps/`

api — tRPC API on Elysia; BullMQ producer; per-user credentialed integrations (exchanges, brokerages) live here so creds don’t cross the tenant boundary.
worker — BullMQ consumer; runs every scheduled + user-initiated job in one binary. Repeatable schedules live in packages/infra/queue/src/queue-names.ts:REPEATABLE_SCHEDULES; the worker registers them with BullMQ at boot.
data-provider — tRPC service that centralizes outbound third-party calls (CoinGecko, Finnhub, DeFiLlama, ExchangeRate-API, Google Sheets, OpenAI, Perplexity, DeepSeek). The same binary serves all three deployment tiers.

Organized by role into four category folders.

Things that change when the product changes.

domain — Services, repositories, use cases (the bulk of business logic).
jobs — Async-job catalog: per-job descriptors (payload schemas, retry policies, jobId strategies, summarizers), repeatable schedules, and the @scani/queue mirror/lock impls. Apps import descriptors from here; processor classes live in apps/backend/worker.
shared — Frontend-safe contract: zod DTOs (the tRPC wire) + the project-configured Decimal.js instance + UI helpers (formatCurrency, formatRelative, emailSchema, …). Strict rule: no Node-only APIs reachable from the barrel.

No business knowledge; reusable in any TypeScript backend.

db — Drizzle schema, migrations, postgres.js connection, BaseRepository.
queue — Async-coordination framework on BullMQ. Abstract bases (UserJobProcessor, ScheduledJobProcessor, EnqueueService, JobLock, ResourceLock, LifecyclePublisher) + concrete @Service() impls. Domain-free.
email — Email sending (Fastmail JMAP / SMTP).
logging — Structured logging (pino).
security — Secret-handling: AES-256-GCM credential encryption with scrypt-derived keys.
storage — Object storage abstraction (any S3-compatible store).
realtime — Realtime / SSE pub-sub via Redis.
rate-limiter — Resilience primitives for upstream calls: rate limiting (Redis-backed in prod, in-memory fallback in tests), per-provider circuit breakers, retry-with-backoff.
config — Env-validation primitives (requiredInProd, httpsUrlInProduction, …) consumed by every app’s startup schema.

Same dependency direction (business → clients → external world).

providers — Unified 3rd-party integration package: pricing, balances, transactions, AI inference, token-identity. Capability-based interfaces, one directory per provider. Single source of truth for every external service.
cloud-client — Typed tRPC client for the data-provider service.

ui (@scani/ui) — Design system + shared client plumbing for the SPA. Ships the Tailwind preset + CSS tokens, the full shadcn primitive set, ThemeContext, ErrorBoundary, UpdateBanner, MagicCodeInput, the useAppUpdate hook, PWA helpers, and the createScaniAuthClient / createTrpcProvider factories.

What	Where
tRPC routers	`apps/backend/api/src/presentation/routers/`
Queue names + enqueue helpers	`packages/infra/queue/src/{queue-names,enqueue}.ts`
Worker processors	`apps/backend/worker/src/processors/`
Repeatable schedules registry	`packages/business/jobs/src/scheduled-jobs/`
Domain services / repositories / use cases	`packages/business/domain/src/`
DB schema	`packages/infra/db/src/schema/`
Drizzle migrations	`packages/infra/db/src/migrations/`
Provider registry	`packages/clients/providers/src/`
Data-provider tRPC routers	`apps/backend/data-provider/src/presentation/`
Test preload	`packages/business/domain/test-preload.ts`