
Web App vs SaaS vs Mobile App: Which One Should You Actually Build?
May 20, 2026
The boring, opinionated answer to what to build your SaaS on in 2026 - for founders who want to ship, not debate. Real stack picks for auth, database, billing, hosting, and AI.
Loic Bachellerie
May 14, 2026

If you have been reading "best SaaS stack 2026" articles, you have probably noticed that every author recommends the stack they personally know. The Rails crowd says Rails. The Django crowd says Django. The TypeScript crowd says Next.js. The Bun crowd says Bun. They are all kind of right and they are all kind of selling you on their comfort zone.
This article is not different. It is opinionated. The difference is we will tell you exactly what tradeoffs each pick makes, so when you outgrow our recommendation, you will know why.
For a typical Canadian SaaS MVP - solo or small founding team, $40K to $150K budget, 12 to 20 week build - here is the stack we recommend by default:
| Layer | Pick | Why |
|---|---|---|
| Frontend framework | Nuxt 4 (or Next.js 15) | SSR, file-based routing, image optimization, fast |
| Styling | Tailwind CSS 4 + shadcn-vue / shadcn (React) | Speed, no design system rewrites |
| Auth | Supabase Auth (or Clerk for enterprise SSO) | Email, OAuth, magic links - done in a day |
| Database | Postgres on Supabase | Real DB, row-level security, generous free tier |
| Backend | Supabase Edge Functions + a few Nuxt server routes | No separate API service to maintain |
| Billing | Stripe with the Customer Portal | The default. There is no second place. |
| Resend | Transactional + broadcast, $20/mo gets you far | |
| File storage | Cloudflare R2 or Supabase Storage | R2 wins on egress cost at scale |
| Background jobs | Trigger.dev or Inngest | Serverless-friendly, retries done right |
| Hosting | Vercel | The fastest "git push to live" workflow we know |
| Error tracking | Sentry | The standard. Worth the $26/month from day one. |
| Product analytics | PostHog | Funnels, session replay, feature flags, all in one |
| AI integration | Vercel AI SDK + Claude API / OpenAI | Provider-agnostic, streams responses, good DX |
This stack costs roughly $100 to $300/month to run at MVP scale and scales to $1K-3K/month at $30K+ MRR. Most of it has a generous free tier you will not hit until you have real customers.
Firebase is great for mobile-first apps and prototypes. It struggles when you need real relational queries, transactions, or multi-tenant isolation. We use it for specific projects (especially mobile + web companion builds), but Postgres on Supabase is the safer default for SaaS.
You can. Most founders should not. AWS gives you 200 services and 200 ways to screw up the IAM permissions. By the time you have configured a VPC, an RDS instance, an ALB, an ECS cluster, and a Cognito setup, your competitor has shipped on Vercel + Supabase. AWS is the right call once you have a real DevOps team or specific compliance requirements that demand it.
Promising. We use Workers for specific edge cases. D1 still lacks the maturity of Postgres for typical SaaS queries (joins, aggregations, complex constraints). Watch this space - it will be the default by 2027.
If you already know one of these, ship in it. Seriously. The framework is rarely the bottleneck. We ship Nuxt and Next.js because we are fastest in them; if you are fastest in Rails, build in Rails. The wrong reason to switch frameworks is because someone on Twitter said your stack is dated.
Add Liveblocks or build on Supabase Realtime. Don't try to roll your own websocket layer in week one.
Meilisearch (self-hosted on Fly.io, ~$10/mo) or Typesense Cloud. Postgres full-text search works fine until ~100K rows, then you'll want something purpose-built.
Inngest for serverless, BullMQ + Redis if you have a Node server, Sidekiq if you are on Rails. The "I'll use cron" approach hits a wall by week 12.
Replace Supabase Auth with Clerk (better SSO, SAML, organizations out of the box) or WorkOS (the standard for B2B enterprise auth). Budget another $50-200/month.
Use the Vercel AI SDK with Claude (Anthropic) as the default. Anthropic's Claude 4.x is the strongest mainstream model for product use right now (2026). Stream responses, cache aggressively, and use prompt caching to cut token costs by 50 to 90 percent on systems with stable prompts. Have a fallback to OpenAI GPT-5 for redundancy.
Even if you have one customer, structure your data with a tenant_id column and row-level security policies enforcing it. Retrofitting multi-tenancy into a single-tenant schema is a 3-to-6-week migration project. Do it on day one and it is 3 hours.
Set up Sentry and PostHog before you launch. The first bug a paying customer hits without observability is the bug you cannot reproduce, and that customer is gone. $50/month of tooling buys you the difference.
If you sell to businesses, an audit log of "who did what when" is non-negotiable. Build it as a generic table from week one. You will thank yourself when your first enterprise customer asks.
In 2026 there is no excuse. Supabase Auth, Clerk, Firebase Auth, or Auth0 - pick one. Rolling your own is a security risk you do not need.
Forget the "best stack." There is no best stack. Pick the stack where:
The stack above hits all four for most Canadian SaaS founders we work with. Yours might be different - and if it is, the free strategy call is the right time to talk through it.
Let's discuss how we can help you achieve your goals online.