--- title: Tiny Solutions description: Early Intervention case management section: craft tags: [project, production-healthcare] genre: reference stability: stable lastUpdated: 2026-04-19 url: https://fardiniqbal.com/docs/craft/projects/tiny-solutions --- Multi-tenant case management for NY Early Intervention agencies. A Rails 8.1 monolith that runs the intake, clinical, and billing pipeline for pediatric therapy agencies coordinating developmental services for children ages 0–3. Row-level tenant isolation, immutable audit trail, Packwerk-enforced domain boundaries, 158 migrations under version control. ## What it is [#what-it-is] Agencies receiving Early Intervention referrals from NY municipalities need to move a child from referral to evaluation to ongoing service delivery to insurance claim inside a single system that keeps a clean HIPAA audit trail. This app is that system. The codebase is organized as concept-driven Rails — `app/concepts/{ai, audit, billing, claim, client, compliance, evaluation, export, lock, note, role, search, sharing, tenant}` — each with its own `package.yml` Packwerk boundary. Every tenant-scoped query is scoped by `agency_id` via `acts_as_tenant`. Every clinical write is versioned by PaperTrail with field-level diffs. A Next.js rewrite of the same domain is in progress in `tiny-solution-next`; this page covers the Rails system that is the authoritative implementation today. ## By the numbers [#by-the-numbers] | Metric | Value | | --------------------- | --------------------------------------- | | Rails version | 8.1 | | Ruby version | 3.4 | | Database migrations | 158 | | Packwerk domain packs | 14 | | Multi-tenancy | Row-level via `acts_as_tenant` | | Audit trail | PaperTrail 17.x (immutable, per-tenant) | | EDI formats | X12 837P (claim) + 835 (remittance) | | Accessibility bar | WCAG 2.1 AA (axe-core in system tests) | | Test framework | Minitest + Capybara + Cuprite | | CI | Sharded across parallel runners | ## Architecture [#architecture] ``` Browser (Turbo + Stimulus + ViewComponent) | Rails 8.1 monolith | app/concepts/ ai/ AI-assisted clinical note quality (AWS Bedrock) audit/ PaperTrail wiring, audit read models billing/ Rate tables, fee schedules claim/ EDI 837P generation, 835 remittance reconciliation client/ Child, guardian, sibling, demographics compliance/ Consent, state-mandated forms, expirations evaluation/ Initial / ongoing evaluation workflows export/ Report generation (xlsx, PDF) lock/ Record locking, edit coordination note/ Session notes, AASM state machine role/ Custom roles, per-user permission overrides search/ OmniSearch: PostgreSQL full-text across tenants sharing/ Cross-agency data sharing contracts tenant/ Agency context, multi-agency switching | Packwerk check (boundary enforcement in CI) | PostgreSQL (Neon, us-east-1) — single data plane | Solid Queue / Solid Cache / Solid Cable on Postgres (no Redis dependency) ``` Each pack declares its boundary in `package.yml`. Cross-pack calls go through public APIs. `packwerk check` runs in CI. PaperTrail records immutable versions with field-level `object_changes` on every clinical mutation, scoped per-tenant, never deleted. ## Key features [#key-features] * **Kanban intake pipeline** — referral staging with drag-through workflow from initial intake to active case. * **Child records with ICD-10 codes** — structured demographics, diagnoses, and sibling linking across families. * **Auto-save on blur** — clinical forms persist field-by-field, no explicit submit. * **OmniSearch full-text** — PostgreSQL `tsvector` indexes across child, guardian, and note records, scoped per tenant. * **State-mandated form generation** — Active Storage for consent documents with `hexapdf` AcroForm fill for NY DOH PDFs. * **EDI 837P / 835** — X12 837P medical claim generation and 835 remittance parsing via `stupidedi`. * **HIPAA-compliant audit trails** — PaperTrail immutable versions satisfying 45 CFR 164.312(b), scoped per tenant. * **AASM state machines** — workflow models (e.g. `DemographicEditRequest`) with typed transitions. * **Packwerk domain boundaries** — 14 concept packs with explicit public APIs and dependency declarations, enforced in CI. * **Pundit authorization** — plain-Ruby policies per concept, no DSL. * **Soft-delete** — `discard` gem; no destructive deletes on clinical tables. * **Strong migrations** — dangerous migrations caught at dev time before they reach production. * **Cross-agency sharing contracts** — explicit sharing concept governs what data a referring agency can expose to a receiving one. * **Record locking** — dedicated `lock/` pack coordinates concurrent edits on clinical records. * **AI-assisted note quality** — AWS Bedrock checks clinical notes for completeness before they advance in the state machine. * **OCR pipeline** — `rtesseract` + `ruby-vips` for extracting text from uploaded consent scans. ## What makes it stand out [#what-makes-it-stand-out] * **Concept-driven Rails.** 14 Packwerk packs with declared public APIs — the monolith reads like a well-bounded modular system, not a Rails-ball-of-mud. * **Row-level tenant isolation at the model layer.** Every clinical table scopes by `agency_id` through `acts_as_tenant`; isolation is not a controller concern. * **Single-Postgres data plane.** Solid Queue, Solid Cache, and Solid Cable all run on the same Neon instance — jobs, cache, and WebSockets with zero Redis. * **Audit-first by construction.** PaperTrail records immutable, field-level diffs on every clinical mutation, scoped per tenant and never deleted — 45 CFR 164.312(b) satisfied structurally. * **Accessibility enforced in tests.** Capybara + Cuprite system tests assert WCAG 2.1 AA via axe-core; a11y regressions fail CI, not review. * **EDI done properly.** `stupidedi` for X12 837P claim generation and 835 remittance reconciliation — the billing pipeline talks the format insurers actually accept. * **158 migrations, all versioned.** Schema history is the system-of- record for how the domain evolved; `strong_migrations` catches dangerous changes at dev time. ## Stack [#stack] | Layer | Technology | | ---------------- | ---------------------------------------- | | Web framework | Rails 8.1 | | Language | Ruby 3.4 | | Database | PostgreSQL (Neon, us-east-1) | | Frontend | Turbo + Stimulus + ViewComponent 4.x | | Multi-tenancy | `acts_as_tenant` (row-level) | | Audit trail | `paper_trail` 17.x | | Authorization | `pundit` 2.5 | | State machines | `aasm` 5.5 | | Background jobs | Solid Queue | | Cache | Solid Cache | | WebSockets | Solid Cable | | EDI | `stupidedi` (837P / 835) | | PDF | `hexapdf` (AcroForm fill) | | OCR | `rtesseract` + `ruby-vips` | | Soft delete | `discard` | | Migration safety | `strong_migrations` | | AI | AWS Bedrock (clinical note quality) | | Deploy | Kamal | | Testing | Minitest + Capybara + Cuprite + axe-core | ## Links [#links] * **Source:** [github.com/FardinIqbal/tiny-solution](https://github.com/FardinIqbal/tiny-solution) * **Next.js rewrite:** [github.com/FardinIqbal/tiny-solution-next](https://github.com/FardinIqbal/tiny-solution-next)