AI accelerates SaaS prototyping, but real scalability and reliability demand expert developers and a modern agency. Discover why in 2025, this duo is essential.
Six months ago, a non-technical founding duo contacted us: their MVP was “vibe-coded” with a Large Language Model (LLM), built in three weekends. Demos dazzled, first customers paid. But soon: production incidents, cloud costs skyrocketing, migration nightmares, and authentication holes. In just six weeks, we rebuilt the core (API contracts, Drizzle migrations, CI/CD, monitoring), secured auth, and reduced release time by 80%. The lesson: AI accelerates, but it does not replace engineering.
The purpose of this article? To explain where AI excels, where it fails, and how the Developer × Agency duo transforms a good idea into a reliable, profitable, and scalable SaaS.
Chaining prompts with an LLM to generate an app, iterate until “it runs.”
Ultra-rapid prototyping (landing pages, CRUD, scaffolding)
Customer demos and market testing
Boilerplate generation (hooks, simple components)
Inconsistent data models between front/back
Security gaps: poorly integrated auth, classic vulnerabilities (injection, IDOR)
No SRE: weak logs, no metrics or alerting, unclear RPO/RTO
Technical debt: no contracts, manual migrations, missing tests
Product misalignment: no clear link between business goals and architecture
Golden Rule: AI writes code. Developers design systems.
The SaaS market is booming, 85% of business apps are SaaS by 2025. But serious SaaS remains more than code:
Auth & Identity: SSO, OAuth, organization/role management, session hardening.
Ex: Better-Auth, Lucia, Clerk.
Data & Models: Versioned schema, reproducible migrations, partitioning for scale.
Drizzle ORM + Neon/Postgres, ElectricSQL for offline sync.
API Contracts: Contract-first (oRPC/tRPC/GraphQL) + validation (Zod).
Goal: one source-of-truth type for client/server.
Back-office & Jobs: Workers, queues, retention, idempotence.
Deno/Node workers, Inngest/Queues.
Security: RBAC/ABAC, secrets management, encryption, bastions, least privilege.
Observability: Structured logs, metrics (p95), distributed traces, error budgets.
OpenTelemetry, Sentry, Grafana/Tempo.
CI/CD: Unit/e2e tests, preview envs, feature flags.
Graphite (stacked PRs), Playwright, GitHub Actions.
Edge & Performance: Cache, ISR/SSG, CDN rules, images, critical scripts.
Vercel/Cloudflare, performance budgets (LCP/TTFB).
Compliance & Governance: GDPR, logging, retention, DPA, data residency.
Field note: 80% of incidents we see stem from missing contracts, migrations, and observability, not missing features.
Boilerplate generation (forms, CRUD, React hooks, skeleton tests)
Guided refactors (component extraction, type mapping)
Internal docs (JSDoc, README, usage examples)
Architecture: Boundaries, domains, responsibilities
Data Modeling: Normalization, indexing, migrations
Security & Compliance: Threat modeling, DPA
Product Strategy: MVP scoping, measurement, pricing
Ops: SLO/SLA, runbooks, incident response, cost awareness
Operating Principle: AI is a fast train on rails, the rails are laid by developers and architects. A modern agency lays the rails.
Define Outcomes & Metrics
Contracts Before Code
AI Scaffolding (With Guardrails)
Test First
Stacked PRs & Reviews (Graphite)
Observability from Day One
Release Train
Product Loop
In short: Machines write faster, humans frame better.
Before:
Single repo without contracts; 5 distinct user models; no migrations; silent 500 errors.
Manual deployments, untracked incidents, unpredictable cloud bills.
After (6 Weeks):
oRPC contracts + Zod; Drizzle migrations; Better-Auth with multi-org support.
CI/CD + e2e tests; Sentry + OTel; feature flags for progressive rollout.
Result: Predictable deployments, traceable incidents, controlled costs.
Product impact: Faster onboarding, weekly feature drops with no regressions.
Stack mastery: Next.js / TanStack Start, Hono, oRPC, Drizzle, Neon, ElectricSQL, Vercel/Cloudflare
Contract-first: Show a sample contract + shared types
Quality: Integrated tests, preview envs, stacked PRs, incident runbooks
Security: Secrets policy, RBAC/ABAC, threat modeling basics
Observability: Dashboards delivered from v1
Governance: Code ownership with you, clean transfer, docs
Transparency: Cadence, SLOs, planning, cloud cost estimate
Phase 0 , Scoping Sprint (1–2 weeks): Outcome, key contracts, wireframes, obs plan, MVP backlog.
Phase 1 , Pilotable MVP (4–8 weeks): Auth + 1 end-to-end flow, observability, payments if relevant, release train.
Phase 2 , Scaling Up (ongoing): Advanced security, performance budget, cost controls, data lifecycle, analytics.
Pay for flows, not pages: Every deliverable should link a user action to a business metric.
“We’ll handle auth later” → security debt and expensive rewrites
“No tests: we’ll go faster” → you’ll go fast… in circles
“Single flexible Json schema” → impossible migrations, subtle bugs
“Logs = console.log” → can’t explain incidents to clients
“Do everything with LLM” → no clear ownership, misaligned code
Multi-org auth + session hardening
RBAC/ABAC defined
Versioned API contracts (oRPC/tRPC) + Zod
Drizzle: tested migrations, rollback strategy
Unit + e2e tests (critical paths)
Sentry + traces + performance dashboards (p95/p99)
Reproducible CI build + preview envs
Feature flags + canary release
Secrets policy & rotation
Data policy: retention, purge, tested backups
SLA/SLO documented (+ on-call if B2B critical)
Cloud budget monitored (cost alerts)
Log policy (PII, GDPR)
Incident runbooks
Code ownership with you + transfer docs
“Vibe coding” has democratized creation. To last, SaaS needs architecture, security, observability, and a product loop that turns code into value. The AI × Developer × Agency trio isn’t a luxury: it’s the winning setup for transforming ideas into impact, without burning time or customer trust.
Question for you: If you were to launch tomorrow, what single business flow would you deliver first (from signup to “aha moment”)? How would you measure it?
Next gentle step: We offer a 10-day Scoping Sprint: walk away with contracts, schema, obs plan, and MVP roadmap. Or, get a free 20-minute express repo audit, we’ll list your top 5 priorities.
Ready to level up? Reach out. We’ll help you move from prompt to platform.
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Leonard
Co-fondateur
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