- Most SaaS development guides are written by agencies trying to sell you services. This one is for founders building it themselves. - The modern SaaS stack in 2026: Next.js, Supabase, Vercel, Stripe, Resend, PostHog. You can ship a production-grade SaaS on all of these for $0 until you have paying customers. - Build the smallest thing that proves the problem is real before touching infrastructure, multi-tenancy, or scale. - Multi-tenancy, auth, and billing are the three things that take longer than founders expect. Plan for them early. - Once you're shipping, you need a system to track what to build next, what deployed, and whether it's working. That's where AdeptDev comes in.

## The SaaS Development Guide Nobody Writes Most guides on SaaS app development are written by agencies. The advice is structured around hiring a team, selecting an enterprise architecture, and managing a six-month development process with stakeholders and ceremonies. That's not your problem. If you're building a SaaS product yourself, you have an idea, a laptop, and a finite amount of time before you need to know whether this thing is going to work. You need to know what to build first, what stack to use, what to skip until later, and how to ship something real without spending three months on infrastructure that might not matter. This guide covers every stage of SaaS application development: from validating the idea to choosing the stack, pricing, security, testing, and getting your first users. Opinionated and written for someone who is going to build it themselves.

## What SaaS App Development Actually Is SaaS (Software as a Service) is software delivered over the internet on a subscription basis. Users pay monthly or annually to access the product through a browser or app. Your infrastructure handles everything: no installation, no update prompts, no local setup for the user. From a technical perspective, SaaS development has four characteristics that shape every decision you make. **Multi-tenancy.** Multiple customers share the same application, but their data is completely isolated. User A never sees User B's data. This is enforced at the database level, the application level, or both. **Subscription billing.** Revenue is recurring. You handle signups, free trials, upgrades, downgrades, failed payments, and cancellations, not just a one-time checkout. **Always-on infrastructure.** Your product needs to be live and fast for users in different time zones. Deployments happen without downtime. Bugs in production affect real people immediately. **Continuous shipping.** Unlike a project with a delivery date, a SaaS product is never finished. You ship, measure, improve, and repeat indefinitely. These four things are what makes SaaS app development distinct from building a website or a one-off application.

## Validate the Idea Before You Build The most expensive mistake in SaaS development is building something nobody wants. It sounds obvious. It's still the most common failure mode. Validation doesn't mean surveys. It means finding people with the problem you're solving and getting signal that they'd actually pay to have it solved. **Talk to 10 people who have the problem.** Not your friends. Not people who will be polite. People who currently deal with the pain you're targeting. Ask how they solve it today, how often it comes up, and how much it costs them in time or money. If they can't describe the pain clearly, the problem might not be real. If they've tried multiple tools to solve it, that's a green light. **See if people are already paying for something adjacent.** If your target market is paying for a workaround, a consultant, or a more complex tool that partially solves the problem, you have evidence of willingness to pay. No competition usually means no market, not opportunity. **Build the smallest thing that tests the core assumption.** A landing page with a signup form. A Loom demo. A manual version of the product you run yourself. Charge for it before you build it, or at minimum get people to commit their email address. The question you're trying to answer before writing production code: would a specific type of person pay a specific amount per month for this? Get 10 people to say yes with specificity, then build. If you're still getting vague encouragement from people who don't want to be rude, keep digging.

## The SaaS Stack in 2026 The right SaaS stack is one you can move fast with, that covers every layer you need, and that has free tiers until you're generating revenue. Here's what that looks like in 2026 for a founder building solo or with a small team. **Frontend and backend: Next.js** Next.js with the App Router is the default for SaaS app development in 2026. React Server Components for fast server-side rendering, Server Actions for mutations without separate API routes, file-system routing, and first-class TypeScript support. It deploys to Vercel in seconds. The reason to use Next.js over alternatives like Remix or a separate React frontend plus Node API is consolidation. One codebase, one language, one deployment. For a solo founder that's fewer things that can break and fewer context switches during the day. **Database and auth: Supabase** Supabase gives you a managed Postgres database, authentication, storage, and real-time subscriptions in one platform. The free tier covers 50,000 monthly active users and 500MB of database storage. Enough to get through your first users without paying anything. One thing to know about the free tier: projects are paused after 7 days of inactivity. This isn't an issue for a product people are actually using, but it will catch you off guard if you walk away from a staging project for a week. The fix is a simple scheduled ping to keep the project active. The auth system integrates directly with Postgres Row Level Security. You enforce data access rules at the database level, not in application code. A user can only read their own rows. An org member can only read their org's data. The database enforces it, not code that can have bugs. **Deployment: Vercel** Every push to main is a production deploy. Every branch gets a preview URL. Rollbacks take one click. For a SaaS product that ships continuously, Vercel removes every deployment decision that doesn't involve writing code. The Hobby plan is free. **Payments: Stripe** Stripe charges 2.9% plus 30 cents per transaction with no monthly fee. It handles subscriptions, free trials, the hosted customer portal, failed payment retries, and webhook events. No monthly cost until you process a payment. **Email: Resend** Transactional email (password resets, welcome emails, billing notifications) with a clean API and React Email for building templates as React components. Free tier: 3,000 emails per month, 1 custom domain. **Analytics: PostHog** Product analytics, session replay, feature flags, and A/B testing in one platform. Free tier: 1 million events per month. Built for product teams, not marketers. **The full SaaS stack at a glance:** | Layer | Tool | Free tier | |---|---|---| | Frontend + backend | Next.js | Free | | Database + auth | Supabase | 50K MAU, 500MB | | Deployment | Vercel | Unlimited deploys | | Payments | Stripe | No monthly fee | | Email | Resend | 3K emails/mo | | Analytics | PostHog | 1M events/mo | You can ship a production-grade SaaS on this stack for $0 until you have paying customers.

## SaaS Pricing: How to Price Your Product SaaS pricing is not just a number you pick. It's a signal about who your product is for and what kind of business you're building. Most founders underprice. The instinct is to charge less to remove friction. The result is a customer base that demands the most and tolerates the least. Run this math before you set a price: | Monthly price | Customers for $5K MRR | Customers for $10K MRR | |---|---|---| | $9/mo | 556 | 1,112 | | $29/mo | 173 | 345 | | $49/mo | 102 | 205 | | $99/mo | 51 | 102 | Getting to 1,112 customers is a completely different business than getting to 102. Different acquisition channels, different support load, different churn math. For most developer-built B2B SaaS products, $49 to $149/month is the right starting range. Low enough that it's a routine business expense. High enough that meaningful MRR requires a manageable number of customers. **Start flat.** One price, everything included. Add tiers only when you have evidence that different types of customers get meaningfully different amounts of value. Tiers are harder to communicate and harder to maintain. **Free trial, not freemium.** A 7 to 14 day free trial with full access converts better than a permanently limited free tier for most B2B SaaS products. Freemium works when you have strong viral mechanics and near-zero marginal cost per free user. Most early products have neither. **Offer annual billing from day one.** Annual subscribers churn at roughly one-third the rate of monthly subscribers. Offer 15 to 20 percent off and make annual the default selection on your pricing page.

## What to Build First This is where most SaaS development projects go wrong. Founders spend the first month on infrastructure (multi-tenant architecture, complex auth flows, admin dashboards, elaborate onboarding) before knowing if anyone wants the product. **1. The core workflow, nothing else.** What is the one thing your product does that users can't easily do without it? Build that. Ignore auth, billing, settings pages. If you're building a tool that saves developers 30 minutes a day, build the thing that saves the 30 minutes. The most common mistake is building the wrapper around the product before the product itself. Login screens, profile pages, subscription gates. These feel like product work but they're infrastructure. They wait. **2. Enough auth to test with real users.** Once the core workflow exists, add the minimum auth needed to let someone else use it. Email and password with Supabase Auth takes about two hours. Google OAuth takes another hour. This is enough to invite your first users. **3. The feedback loop.** Before adding billing, instrument the product with PostHog and start learning. Where do users get stuck? What do they use and what do they ignore? Do they come back? These answers matter more than anything you build next. **4. Billing.** Once you know the product is working and users return, add billing. Stripe Checkout plus a webhook handler for the five key events is the minimum. It takes a day, not a week. **5. Everything else.** Multi-tenancy for teams, admin dashboards, advanced settings, email sequences. These come after you have proof that someone wants to pay for the thing.

## The Three Things That Take Longer Than You Think **Multi-tenancy** Multi-tenancy sounds simple: different users get different data. In practice it involves decisions that affect your entire database schema from day one. For most early-stage SaaS products, a single database with Row Level Security is the right approach. Supabase makes this work because RLS integrates directly with the auth system. But you need to design this upfront. Retrofitting multi-tenancy into an existing schema is painful. ```sql -- Every table that has tenant data needs an org_id column create table projects ( id uuid primary key default gen_random_uuid(), org_id uuid references organizations(id) on delete cascade, name text not null, created_at timestamptz default now() ); -- RLS policy: only org members can read projects create policy "Org members can read projects" on public.projects for select using ( exists ( select 1 from org_members where org_members.org_id = projects.org_id and org_members.user_id = auth.uid() ) ); ``` Once this policy exists, every query against `projects` is automatically scoped to the right org. Application code can't accidentally leak cross-tenant data. **Auth** OAuth, magic links, team invitations, role-based access control: each one adds more time than it looks. OAuth alone requires handling callback URLs, token storage, account linking, and edge cases like what happens when a user signs up with Google and then tries to sign in with their email. The practical advice: use Supabase Auth. Setup time for OAuth with Supabase is 30 minutes per provider, not 30 minutes for all of them. **Billing** Stripe's webhook system is reliable but there are more events to handle than first-time implementers expect. `checkout.session.completed`, `customer.subscription.updated`, `customer.subscription.deleted`, `invoice.payment_failed`, and `customer.subscription.trial_will_end` are the core five. Getting the handler right (signature verification, idempotency, correct HTTP responses) takes a full day. The most common mistake: trusting the redirect back to your success URL as confirmation of payment. It's not. The webhook is the source of truth. Only update your database when the webhook fires.

## SaaS Architecture: What You Actually Need Early On Good SaaS architecture early on means the opposite of what most guides recommend. Most architecture guides for SaaS app development describe systems you don't need until you have 10,000 paying customers. Microservices, event queues, Kubernetes clusters, read replicas, CDN-distributed databases. These solve real problems at scale. They create complexity problems at the early stage. Here's what you actually need: **A monolith.** One Next.js app, one Supabase project, one Vercel deployment. This is not a compromise. It's correct architecture for an early-stage SaaS. You can split services out later. Merging a prematurely split system back together is miserable. **Server-side rendering for the authenticated experience.** React Server Components mean your dashboard pages load with data already populated. No loading spinners, no client-side fetch waterfalls. Better UX and better performance with less code than a SPA approach. **Database indexes on the columns you query.** The most common early-stage performance problem is unindexed foreign key columns. Every `user_id`, `org_id`, or `created_at` column you filter or sort by should have an index. Supabase's dashboard shows slow query logs. Check it weekly. Skip microservices, message queues, and Kubernetes until you have evidence you need them. Meaning actual performance problems at actual scale.

## Security Basics Every SaaS Needs Security doesn't mean building a fortress. It means not having obvious holes. Here's what actually matters at the early stage. **Environment variables, not hardcoded secrets.** Your API keys, database strings, and Stripe secret keys live in environment variables. Never in code. Never in `.env` files committed to the repository. If you accidentally commit a secret, rotate it immediately. **HTTPS everywhere.** Vercel handles this automatically. Your custom domain gets a TLS certificate provisioned on deployment. Nothing to configure. **Row Level Security before you launch.** Enable RLS on every Supabase table that contains user data and add policies before the table is in production. Turning on RLS after data exists is riskier than doing it from the start. **Rate limiting on auth endpoints.** Without rate limiting, anyone can attempt thousands of password combinations against your login page. Supabase's auth has built-in rate limiting but if you're building custom auth routes, add rate limiting with Upstash Redis or a similar service. **Validate inputs server-side.** Client-side validation is UX. Server-side validation is security. Use Zod to validate every request body in your Server Actions and Route Handlers. Never trust what comes from the client. **Stripe webhook signature verification.** Every webhook event from Stripe must be verified using `stripe.webhooks.constructEvent` with the raw request body and the webhook signing secret. Without this, anyone can POST fake events to your endpoint and provision access for free. The things that come later (after you have enterprise customers asking for them): penetration testing and SOC 2. They matter. They just don't matter on day one.

## Testing: What to Actually Write Most early-stage SaaS products have too little testing. A small number have too much. Here's what's worth writing. **Test your billing logic.** The code paths handling subscription creation, upgrades, and cancellations are the most dangerous to get wrong. A bug in checkout costs you revenue. A bug in cancellation logic means free access for people who cancelled. ```ts test("checkout.session.completed creates user subscription", async () => { const session = mockCheckoutSession({ userId: "user_123" }); await handleCheckoutCompleted(session); const user = await db.users.findUnique({ where: { id: "user_123" } }); expect(user?.subscriptionStatus).toBe("active"); expect(user?.stripeSubscriptionId).toBeTruthy(); }); ``` **Test your auth and access control.** Test that a user cannot access another user's data. Test that unauthenticated requests are rejected. These tests catch the most embarrassing bugs. **Don't write E2E browser tests yet.** End-to-end tests are slow, brittle, and expensive to maintain. At the early stage, the time spent writing Playwright tests for your onboarding flow is better spent talking to users. Add E2E tests when the product is stable enough that the UI rarely changes. **Run `tsc --noEmit` and your test suite on every push.** TypeScript errors and failing tests should block a deploy. Vercel's built-in CI handles this if you add the check command to your build configuration. The testing philosophy for early-stage SaaS: test the things that cost you money or customers if they break. Skip the rest until the product is stable.

## Managing SaaS Development Without Losing Track Once you're shipping regularly, you need a system to track what to build next, whether the last deploy went through, and whether what you shipped is working. Most project management tools weren't built for this. Jira is for large engineering teams. Notion requires manual updates. Linear is the best pure issue tracker for developers but doesn't know whether your Vercel build succeeded or whether your last feature moved the metrics. AdeptDev connects your Kanban board directly to GitHub via webhooks. Tasks move automatically when you push code or open a PR. Vercel deployment status surfaces inside the same workspace alongside your tasks. Analytics from PostHog or Google Analytics sit in the same view. Open one tab in the morning: see what's in progress, whether the last deploy succeeded, whether the feature you shipped last week improved activation. No tab switching. No manual board updates. $10/month flat after a 7-day free trial. Try it at [adeptdev.io](https://adeptdev.io).

![AdeptDev Feature Board](https://vyoyxwhjtxsktvvpxdvj.supabase.co/storage/v1/object/public/blog_images/mock-feature-board.png)

## The SaaS Development Checklist Before you launch to real users: **Authentication** - Email and password sign-in working - OAuth provider (Google at minimum) working - Password reset flow working - Session persistence across page refreshes **Data model** - Multi-tenancy enforced at the database level with RLS - Every user-facing table has appropriate RLS policies - Indexes on all foreign key columns you query **Billing** - Stripe Checkout session creation working - Webhook handler live and verified (signature checked) - `checkout.session.completed` updates user subscription status - `customer.subscription.deleted` revokes access - `invoice.payment_failed` marks account as past due **Deployment** - Custom domain configured on Vercel - Environment variables set for production (separate from development) - Database backups enabled (Supabase Pro or manual export schedule) **Monitoring** - PostHog or Google Analytics connected - Sentry error tracking connected - Uptime monitoring in place (Better Uptime or Checkly) **Email** - Resend domain verified (SPF, DKIM, DMARC configured) - Welcome email sending on signup - Password reset email sending correctly

## How to Get Your First Users Launching is not a moment. It's a process. Most first-time founders treat it like a single event when it's actually several overlapping activities. **Start with people who already know you.** Your network, social media followers, communities you're already in. These people give you the most honest feedback and the most benefit of the doubt. Don't save the launch for Product Hunt. Use your network first. **Post where your target users already are.** If you're building a developer tool, post on relevant subreddits, Hacker News (Show HN), dev.to, or Twitter/X. Don't post everywhere. Pick two or three places where your exact user type hangs out and post thoughtfully there. **Show HN works if you have something real.** A Show HN post on Hacker News for a working product with a clear value proposition regularly drives hundreds of signups. The requirements: it actually works, the value prop is immediately clear, and you respond to every comment in the thread. **Don't launch on Product Hunt before you have retention.** Product Hunt is a visibility event, not a validation event. Most products get a spike of traffic, some signups, and then a steep drop. If retention is poor, launching on Product Hunt makes that visible without fixing it. Get to solid retention first. **Content marketing compounds.** Every article you write targeting a keyword your potential users search for is a permanent acquisition channel. This article on SaaS app development drives relevant traffic indefinitely. Start writing early. **The most effective early growth is manual.** DM people in your target market, offer free access, get on calls, watch them use the product. This doesn't scale but it's how you find out what's actually wrong before you try to scale acquisition.

## What Does It Cost to Build a SaaS? **Infrastructure cost before revenue: $0** The stack described in this guide has generous free tiers across every service. Supabase free tier, Vercel Hobby, Resend free tier, PostHog free tier. Stripe charges nothing until you process a payment. You can build and launch to your first hundred users without spending a dollar on infrastructure. **Infrastructure cost as you grow:** | Stage | Monthly infra cost | |---|---| | Pre-revenue (0 users) | $0 | | Early stage (100 to 500 users) | $25 to $75/mo | | Growing (500 to 2,000 users) | $75 to $200/mo | | Scaling (2,000 to 10,000 users) | $200 to $600/mo | The main costs as you grow: Supabase Pro at $25/month when you exceed free tier limits, Vercel Pro at $20/month for team features or higher limits, Resend Pro at $20/month for higher email volume. **The real cost is your time.** At 20 to 30 hours per week, a functional MVP takes 4 to 8 weeks. That's 80 to 240 hours. Every hour spent building infrastructure that doesn't prove the product is a bet on something you don't know yet. Be deliberate about what you build first. **What not to spend money on early:** paid ads before you have retention figured out, expensive monitoring tools, a dedicated server before Vercel's limits actually matter, any contractor before you know exactly what needs building.

## How Long Does SaaS Development Take? Honest answer for a developer building solo: - **Core product MVP:** 2 to 6 weeks depending on complexity - **Auth, billing, and basic infrastructure:** 1 to 2 weeks on top of that - **First version ready for real users:** 4 to 8 weeks total - **First paying customer:** depends entirely on distribution, not development Development is rarely the bottleneck. Most SaaS products that fail do so because of distribution, not because they weren't built correctly. Ship something real as fast as possible, put it in front of real users, and learn from what they do with it. Everything you build before you have users is a bet. The faster you can test that bet with real people, the faster you find out if it's correct.

## Wrap Up SaaS app development in 2026 is genuinely more accessible than it has ever been. The stack is better, the tooling is better, and the infrastructure cost to start is essentially zero. A founder with strong development skills can ship a production-grade SaaS in weeks, not months. If you're figuring out how to build a SaaS app for the first time, the decisions that matter most are made early: choosing a stack you can move fast with, designing multi-tenancy from the start, and building the core product before the wrapper around it. SaaS application development is ultimately a product discipline as much as a technical one. Everything else (project management, deployment tracking, performance monitoring) should support the shipping loop, not complicate it. If you want all of that in one place while you build, check out [AdeptDev](https://adeptdev.io). Free for 7 days.

## What is SaaS app development? SaaS app development is the process of building software delivered over the internet on a subscription basis. It involves designing a multi-tenant architecture where multiple customers share the same application with completely isolated data, implementing subscription billing with tools like Stripe, building on cloud infrastructure that is always available, and shipping continuously as the product evolves. The core technical challenges unique to SaaS are multi-tenancy, recurring billing, and always-on reliability. ## What is the best tech stack for SaaS development in 2026? For founders building a SaaS product themselves, the most practical SaaS stack in 2026 is Next.js for the frontend and backend, Supabase for the database and auth, Vercel for deployment, Stripe for payments, Resend for transactional email, and PostHog for product analytics. Every service has a generous free tier. You can ship a complete SaaS on this stack for $0 until you have paying customers. ## How long does it take to build a SaaS app? For a developer building solo, a functional MVP with auth, billing, and a core feature typically takes 4 to 8 weeks. The core product itself takes 2 to 6 weeks depending on complexity. Auth and billing add 1 to 2 weeks. Development is almost never the bottleneck. Finding paying customers is harder than building the product. ## What is multi-tenancy in SaaS development? Multi-tenancy means multiple customers share the same application instance with completely isolated data. In practice this is enforced through Row Level Security policies in Postgres, which Supabase makes straightforward because the auth system exposes `auth.uid()` inside every policy. Multi-tenancy should be designed into the database schema from day one. Retrofitting it later is significantly more difficult. ## How do I handle SaaS billing? Stripe is the standard. The minimum implementation involves creating a Stripe Checkout session when a user selects a plan, handling webhook events to update your database when subscriptions change, and using the Stripe Customer Portal so users can manage their own billing. The five webhook events that matter most are `checkout.session.completed`, `customer.subscription.updated`, `customer.subscription.deleted`, `invoice.payment_succeeded`, and `invoice.payment_failed`. Never trust the checkout redirect as confirmation of payment. Only trust the webhook. ## What should I build first in a SaaS app? Build the core workflow that solves the problem, before auth, billing, settings pages, or admin dashboards. Once the core exists, add the minimum auth needed to let someone else use it. Then instrument with analytics and watch what real users do. Only add billing after you have evidence that users return and get value. The wrapper around the product (login screens, subscription gates, profile pages) can wait until the product itself is working. ## How do I manage a SaaS development project as a solo developer? Use a Kanban board connected to your GitHub repository so tasks update automatically when you push code. Keep deployment visibility in the same workspace as your tasks so you know immediately when builds succeed or fail. Track one product metric per feature before and after you ship it. AdeptDev connects all three of these into one workspace for $10/month, built specifically for developers managing their own SaaS products.