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Cloud Audit: App Cloud Readiness

Drop Application Cloud-Readiness Audit

MC Task: #1443 Date: 2026-02-19 Auditor: software-arch (CloudForge team) Application: Drop Fintech Payment App (Next.js 15 + SQLite/PostgreSQL dual-driver)

NOTE (2026-03-03): This audit was performed on 2026-02-19. ADR-014 (2026-03-03) removed SQLite and the dual-driver architecture. Drop now uses PostgreSQL 16 exclusively in all environments. SQLite concerns noted in this audit are resolved. The better-sqlite3 dependency has been removed.

1. Twelve-Factor Compliance

I. Codebase — PASS

  • Evidence: Single Git repository at /Users/makinja/ALAI/products/Drop/
  • .github/workflows/ci.yml triggers on main and develop branches
  • One codebase tracked in revision control, multiple deploys (staging via Fly.io, production via Docker Compose)

II. Dependencies — PASS

  • Evidence: package.json:1-55 declares all dependencies explicitly
  • npm ci used in CI (ci.yml:36) and Dockerfile (Dockerfile:6) for deterministic installs
  • package-lock.json referenced in Dockerfile COPY (Dockerfile:5) and CI cache (ci.yml:32)
  • Native modules (better-sqlite3) handled via apk add python3 make g++ in Dockerfile

III. Config — PASS

  • Evidence: .env.example:1-87 documents all env vars with clear groupings
  • env.ts:1-45 validates critical vars at startup, crashes if missing in production
  • fly.toml:16-20 injects env vars at runtime
  • docker-compose.production.yml:7-8 uses ${JWT_SECRET:?} required substitution
  • db.ts:9 — database driver selected via DATABASE_URL env var
  • db.ts:26-30 — SQLite path varies by environment (Vercel /tmp, Docker /app/data, local ./data)
  • Feature flags externalized as NEXT_PUBLIC_FF_* env vars (Dockerfile:19-26)
  • Minor concern: NEXT_PUBLIC_* vars are baked into the build at compile time (Next.js limitation), requiring rebuild for changes. This is inherent to Next.js, not a code deficiency.

IV. Backing Services — PASS

  • Evidence: db.ts:9-22 — database treated as attached resource via DATABASE_URL
  • PostgreSQL connection string is a single env var; switching databases requires zero code changes
  • docker-compose.production.yml:17-35 — PostgreSQL is a separate service with its own health check
  • BankID, PISP, AISP, Stripe, Sumsub — all configured via env vars (.env.example:19-53)

V. Build, Release, Run — PASS

  • Evidence: Dockerfile uses 3-stage build (deps → builder → runner)
  • Dockerfile:1-6 — Stage 1: dependency installation
  • Dockerfile:9-37 — Stage 2: application build with next build
  • Dockerfile:39-64 — Stage 3: minimal production runner
  • next.config.ts:8 — output: "standalone" generates self-contained deployment
  • CI builds Docker image tagged with commit SHA (ci.yml:63)
  • Build-time vs runtime config cleanly separated (ARG for build, ENV for runtime)

VI. Processes — PARTIAL

  • Evidence: Application runs as a single node server.js process (Dockerfile:64)
  • SQLite concern: When running with SQLite (no DATABASE_URL), the process is stateful — data lives on local filesystem at /app/data/drop.db. This works on Fly.io with mounted volumes (fly.toml:36-38) but violates share-nothing for horizontal scaling.
  • PostgreSQL mode: Fully stateless — pg.Pool connects to external database (db.ts:17-22). Multiple processes can run concurrently.
  • Rate limiting: rate_limits table in the database (middleware.ts:15-43), which works for single-instance but has race conditions under horizontal scale with SQLite.
  • Assessment: PARTIAL because SQLite mode is actively used (Fly.io staging). In PostgreSQL mode this would be PASS.

VII. Port Binding — PASS

  • Evidence: Dockerfile:61-62 — EXPOSE 3000, ENV PORT=3000, ENV HOSTNAME="0.0.0.0"
  • fly.toml:23 — internal_port = 3000
  • docker-compose.production.yml:5 — ports: "3000:3000"
  • Self-contained via Next.js standalone server, no external HTTP server dependency.

VIII. Concurrency — PARTIAL

  • Evidence: Node.js single-threaded event loop handles concurrent requests via async I/O
  • db.ts:16-22 — PostgreSQL connection pool (pg.Pool) supports concurrent queries
  • fly.toml:25-27 — auto_stop_machines/auto_start_machines enables horizontal scaling
  • Limitation: No explicit worker process types. Background work (e.g., exchange rate refresh) runs inline. No separate queue workers. For a fintech app, transaction processing should eventually be separated into dedicated worker processes.
  • Limitation: SQLite mode limits to single process (WAL mode allows concurrent reads but single writer).

IX. Disposability — PASS

  • Evidence: Process starts fast — Next.js standalone is ~500ms cold start
  • db.ts:719-789 — initDb() is idempotent with _initialized guard; safe for restarts
  • Schema uses CREATE TABLE IF NOT EXISTS — safe for repeated initialization
  • fly.toml:25-27 — machines auto-stop/start, confirming disposability design
  • Graceful shutdown handled by Node.js default SIGTERM behavior
  • PostgreSQL pool (pg.Pool) handles connection cleanup on process exit

X. Dev/Prod Parity — PASS

  • Evidence: db.ts:9-13 — dual-driver architecture (SQLite for dev, PostgreSQL for prod) with unified async API
  • db.ts:47-63 — SQL compatibility layer translates SQLite idioms to PostgreSQL (placeholder conversion, INSERT OR IGNORE → ON CONFLICT DO NOTHING, datetime('now') → CURRENT_TIMESTAMP)
  • db.ts:204-460 (SQLITE_SCHEMA) and db.ts:462-690 (PG_SCHEMA) — parallel schemas maintained in sync
  • migrations/0001_initial-schema.ts — node-pg-migrate for PostgreSQL schema versioning
  • Docker Compose production config (docker-compose.production.yml) mirrors production topology locally
  • Minor gap: SQLite schema is maintained inline in db.ts while PostgreSQL uses proper migrations (node-pg-migrate). Schema drift is possible if one is updated without the other.

XI. Logs — PARTIAL

  • Evidence: Health endpoint uses createLogger() (health/route.ts:16)
  • middleware.ts:82-84 — error tracking via trackError() and Sentry integration
  • .env.example:62-74 — Sentry DSN configurable via env vars
  • Concern: No structured logging to stdout visible in the codebase. Next.js default logging goes to stdout which is good for containers, but there's no consistent structured logging format (JSON lines) that cloud log aggregators can parse efficiently. console.error is used in places (middleware.ts:83).

XII. Admin Processes — PASS

  • Evidence: package.json:12-14 — migration scripts: migrate:up, migrate:down, migrate:create via node-pg-migrate
  • db.ts:735-774 — programmatic ALTER TABLE migrations for schema evolution
  • Seed data controlled by SEED_DEMO env var and isDemoMode() check — admin data seeding decoupled from main app
  • No one-off scripts embedded in application startup (seeding only runs when database is empty)

2. Containerization Quality

Multi-Stage Build — EXCELLENT

  • 3-stage Dockerfile (Dockerfile:1-64):
    • Stage 1 (deps): node:22-alpine, installs native build tools, runs npm ci
    • Stage 2 (builder): Copies deps, builds Next.js app
    • Stage 3 (runner): Minimal alpine, copies only standalone output + static assets

Image Size

  • Base: node:22-alpine (minimal, ~180MB base)
  • Issue: Stage 3 installs python3 make g++ (Dockerfile:42) for better-sqlite3 native module rebuild. This adds ~200MB to the production image unnecessarily if running in PostgreSQL mode. These build tools are a security and size concern in production.
  • Recommendation: Either pre-build better-sqlite3 in stage 2 and copy the binary, or conditionally exclude it when PostgreSQL is the target.

Security

  • Non-root user: nextjs:nodejs (UID/GID 1001) created and used (Dockerfile:48-49, 58)
  • NEXT_TELEMETRY_DISABLED=1 set (Dockerfile:14, 46)
  • Data directory owned by non-root user (Dockerfile:56)
  • CI runs Trivy vulnerability scanner on built image (ci.yml:67-73) with HIGH/CRITICAL severity gate
  • SARIF results uploaded to GitHub Security tab (ci.yml:85-89)

Layer Caching

  • Dependencies cached in separate stage (Dockerfile:5-6 — COPY package.json package-lock.json* before source)
  • Source code copy happens in stage 2 after deps, enabling Docker layer cache for unchanged dependencies
  • Good practice: Build args for feature flags allow cache invalidation only when flags change

Missing

  • No .dockerignore verified (could copy unnecessary files like .git, node_modules into build context)
  • No image tagging strategy beyond CI SHA tag

3. Database Portability

Dual-Driver Architecture — STRONG

  • Implementation: db.ts:9-13 — Runtime driver selection via DATABASE_URL presence
  • Unified API: query(), getOne(), run(), transaction() — all async, both drivers (db.ts:67-199)
  • Type exports: DbClient interface (db.ts:136-140) for transaction context

SQL Translation Layer

SQLite Idiom PostgreSQL Translation Location
? placeholders $1, $2, ... db.ts:47-50
INSERT OR IGNORE INTO INSERT INTO ... ON CONFLICT DO NOTHING db.ts:56, 104-118
INSERT OR REPLACE INTO INSERT INTO ... ON CONFLICT (col) DO UPDATE SET db.ts:58, 120-134
datetime('now') CURRENT_TIMESTAMP db.ts:60
INTEGER PRIMARY KEY AUTOINCREMENT SERIAL PRIMARY KEY db.ts:278 vs 530
hex(randomblob(32)) encode(gen_random_bytes(32), 'hex') db.ts:248 vs 504

Transaction Support

  • PostgreSQL: BEGIN/COMMIT/ROLLBACK with pgClient.connect() and proper release in finally block (db.ts:142-173)
  • SQLite: db.exec("BEGIN/COMMIT/ROLLBACK") wrapper (db.ts:174-198)
  • Error handling: Both paths catch and rollback on failure

Migrations

  • node-pg-migrate for PostgreSQL (package.json:12-14, migrations/0001_initial-schema.ts)
  • Proper up() and down() functions with ordered table creation/deletion
  • SQLite uses inline schema with CREATE TABLE IF NOT EXISTS + ALTER TABLE try/catch migrations (db.ts:756-774)
  • Risk: Two parallel schema definitions (SQLITE_SCHEMA and PG_SCHEMA in db.ts + node-pg-migrate files) could drift. No automated parity check exists.

Indexes

  • 22 indexes defined for both drivers (identical set)
  • Partial indexes supported: idx_users_national_id WHERE national_id_hash IS NOT NULL, idx_tx_idempotency WHERE idempotency_key IS NOT NULL

4. Config Externalization

Environment Variables

Category Variables Source
Core JWT_SECRET, JWT_EXPIRY, NODE_ENV .env.example:12-14
Database DATABASE_URL db.ts:9
Service Mode NEXT_PUBLIC_SERVICE_MODE, DROP_MODE .env.example:8
Auth (BankID) BANKID_CLIENT_ID/SECRET/URLS, BANKID_MOCK .env.example:19-29
Payments PISP_API_URL/KEY, AISP_API_URL/KEY .env.example:32-40
Cards STRIPE_SECRET_KEY, STRIPE_PUBLISHABLE_KEY .env.example:43-47
KYC SUMSUB_APP_TOKEN, SUMSUB_SECRET_KEY .env.example:50-52
Monitoring SENTRY_DSN, SENTRY_TRACES_SAMPLE_RATE .env.example:63-74
Feature Flags 8x NEXT_PUBLIC_FF_* .env.example:77-87
Exchange EXCHANGE_RATE_API_KEY/URL .env.example:55-59

Secrets Management

  • env.ts:14-45 validates critical vars at production startup
  • Dockerfile:15 — JWT_SECRET=build-phase-placeholder (safe build-time placeholder)
  • env.ts:21-25 — Skip validation during build phase (detects NEXT_PHASE or placeholder)
  • env.ts:36-38 — Rejects known dev placeholder in production runtime
  • docker-compose.production.yml:7 — ${JWT_SECRET:?} required substitution (fails if missing)
  • No hardcoded secrets found in source code

Feature Flags

  • 8 client-side feature flags via NEXT_PUBLIC_FF_* env vars
  • Defaults to false (safe) for all card-related features
  • NEXT_PUBLIC_FF_NOTIFICATIONS=true and NEXT_PUBLIC_FF_MERCHANT_DASHBOARD=true as defaults
  • Build-time injection for client code (Dockerfile:19-35), runtime for server code

5. CI/CD Quality

Pipeline Structure (ci.yml)

lint-test (parallel)          docker-scan (sequential, needs lint-test)
  -- npm ci                     -- docker build
  -- eslint                     -- Trivy scan (table, exit-code=1 on HIGH/CRITICAL)
  -- tsc --noEmit               -- Trivy SARIF -> GitHub Security
  -- vitest run
  -- npm audit (production)

Reproducibility

  • Pinned Node.js version: NODE_VERSION: "22" (ci.yml:15)
  • npm ci for deterministic installs (ci.yml:36)
  • Dependency caching via actions/setup-node with cache-dependency-path (ci.yml:30-32)
  • Docker image tagged with commit SHA (ci.yml:63)

Security Scanning

  • npm audit: Production dependencies, HIGH level, continue-on-error (ci.yml:48-49)
  • Trivy: Container vulnerability scan, blocks on HIGH/CRITICAL unfixed vulns (ci.yml:67-73)
  • SARIF: Results uploaded to GitHub Security tab (ci.yml:85-89)
  • Permissions: Minimal — contents: read, security-events: write (ci.yml:11-12)

Testing

  • vitest run in CI (ci.yml:44)
  • Unit test framework configured (package.json:10-11)
  • Coverage tool available: @vitest/coverage-v8 (package.json:43)
  • Missing: No coverage threshold enforcement in CI
  • Missing: No E2E/integration tests in CI pipeline (Playwright is in devDependencies but not wired into CI)

Deployment

  • Fly.io staging configured (fly.toml) with health checks, auto-scaling, volume mounts
  • Docker Compose production (docker-compose.production.yml) for self-hosted deployments
  • Missing: No automated deployment step in CI (manual fly deploy or similar)
  • Missing: No environment promotion pipeline (develop -> staging -> production)

6. Overall Score and Top 5 Improvements

Overall Cloud-Readiness Score: 7.5 / 10

The application demonstrates strong cloud-native fundamentals:

  • Excellent dual-driver database abstraction
  • Proper multi-stage Dockerfile with security hardening
  • Configuration fully externalized via environment variables
  • Comprehensive CI with security scanning (Trivy + npm audit)
  • Health endpoint with real database connectivity check

Top 5 Improvements (Priority Order)

1. Eliminate Build Tools from Production Image (HIGH)

  • File: Dockerfile:42
  • Issue: python3 make g++ in production stage adds ~200MB and attack surface
  • Fix: Pre-compile better-sqlite3 in builder stage, copy only the .node binary. Or use a conditional build that excludes better-sqlite3 entirely when targeting PostgreSQL.

2. Add Structured Logging (HIGH)

  • Files: Throughout — console.error used in middleware.ts:83, health endpoint has createLogger() but no consistent format
  • Issue: Cloud log aggregators (CloudWatch, Datadog, ELK) need structured JSON logs. Current mix of console.log/error and ad-hoc logger makes log parsing unreliable.
  • Fix: Adopt pino or similar JSON logger, output to stdout in { level, message, timestamp, requestId } format.

3. Add CI Coverage Enforcement and E2E Tests (MEDIUM)

  • File: ci.yml — no coverage gate, no Playwright CI step
  • Issue: @vitest/coverage-v8 and @playwright/test are in devDeps but not enforced in CI
  • Fix: Add --coverage --coverage.thresholds.lines=80 to vitest. Add Playwright E2E job with containerized app.

4. Automate Schema Parity Check (MEDIUM)

  • File: db.ts:204-690 — two parallel schema definitions (SQLite + PostgreSQL)
  • Issue: Manual sync between SQLITE_SCHEMA, PG_SCHEMA, and node-pg-migrate files. Drift will cause runtime errors that only surface in specific deployment targets.
  • Fix: Write a CI check that extracts table/column definitions from both schemas and compares. Or generate both schemas from a single source of truth.

5. Add Deployment Pipeline and Environment Promotion (MEDIUM)

  • File: ci.yml — CI only, no CD
  • Issue: No automated deployment from CI. Fly.io deploy is manual. No staging -> production promotion gate.
  • Fix: Add fly deploy step on develop push (staging) and manual approval gate for main (production). Add smoke test after deploy. Consider GitHub Environments for approval workflows.

Honorable Mentions

  • SQLite mode limits horizontal scaling — document clearly when to switch to PostgreSQL
  • Rate limiting via database has race conditions under concurrent writes (consider Redis for high-throughput)
  • No readiness probe separate from liveness (health endpoint serves both)
  • No graceful shutdown handler (SIGTERM -> drain connections -> exit)
  • playwright-core in production dependencies (package.json:27) — should be devDependencies only

Appendix: File Reference

File Purpose
src/drop-app/src/lib/db.ts Dual-driver database abstraction (SQLite + PostgreSQL)
src/drop-app/Dockerfile 3-stage multi-stage build
src/drop-app/.env.example Environment variable documentation (87 lines)
src/drop-app/fly.toml Fly.io deployment config (Stockholm region)
src/drop-app/docker-compose.production.yml Self-hosted production config
src/drop-app/package.json Dependencies and scripts
.github/workflows/ci.yml CI pipeline (lint, test, type-check, Trivy)
src/drop-app/migrations/0001_initial-schema.ts PostgreSQL migration (node-pg-migrate)
src/drop-app/next.config.ts Next.js config (standalone output, security headers)
src/drop-app/src/middleware.ts Edge middleware (CSRF, CSP nonce)
src/drop-app/src/lib/middleware.ts Server middleware (rate limiting, auth, validation, audit)
src/drop-app/src/app/api/health/route.ts Health endpoint (real DB check)
src/drop-app/src/lib/env.ts Environment validation at startup
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