What is App Stack Builder?

App Stack Builder is a free AI-powered tool that helps founders and developers choose the right tech stack for their projects based on budget, app type, team size, and skill level.

What is the best tech stack for SaaS in 2026?

The best tech stack for SaaS in 2026 typically includes Next.js 16 for frontend, Supabase for database and auth, Vercel for hosting, Stripe for payments, and PostHog for analytics. App Stack Builder can generate a personalized recommendation based on your specific budget and requirements.

Is App Stack Builder free to use?

Yes, App Stack Builder is completely free to use. You can generate unlimited tech stack recommendations without any cost.

What types of apps can I build with the recommended stacks?

App Stack Builder supports various app types including SaaS applications, web apps, mobile apps, e-commerce stores, internal tools, and AI/ML products.

How much does a SaaS tech stack cost per month?

A modern SaaS tech stack can cost anywhere from $0-50/month for bootstrapped startups using free tiers, $100-300/month for growth-stage startups, to $500+/month for enterprise-ready infrastructure. App Stack Builder helps you find the best tools within your specific budget.

What is the best tech stack for solo founders?

For solo founders, we recommend Next.js + Vercel (free), Supabase (free tier), Supabase Auth (free), Stripe (pay as you go), and Plausible or PostHog for analytics. This stack can run your entire SaaS for under $50/month.

Can I export my tech stack recommendations?

Yes, you can export your tech stack recommendations as a PDF document or copy them to your clipboard. You can also share a link to your stack with others.

Database

Convex vs MongoDB Atlas: Which is Better in 2026?

Name: App Stack Builder
Availability: InStock

Choosing between Convex and MongoDB Atlas? Both are popular database tools. Below we compare them on pricing, free tiers, features, and pros & cons so you can pick the right fit for your stack.

Quick verdict

Both are solid database options. Convex is cheaper to start, but the right choice depends on the specific features and integrations you need.

Convex vs MongoDB Atlas — Side by Side

	Convex	MongoDB Atlas
Category	Database	Database
Pricing	Free · paid from $25/mo	Free · paid from $30/mo
Starting price	Free tier available	Free tier available
Free tier
Best for	Database — backend, baas	Database — nosql, mongodb

Pros & Cons

Convex

Excellent real-time data model
Very fast developer iteration
TypeScript-first backend
Built-in cron, auth, and storage
AI-assisted app generation

Pricing is per-developer at scale
Less control than self-managed databases
Ecosystem smaller than traditional databases

MongoDB Atlas

Flexible schema for fast iteration
Excellent global replication support
Strong ecosystem and tooling
Works well for unstructured and semi-structured data

More expensive at scale
Query patterns require careful design
Not ideal for complex relational joins

Choose Convex if…

you want a free tier to start, and Convex Reactive backend-as-a-service with a built-in database, real-time queries, serverless functions, and AI-powered app generation.

Convex review & pricing

Choose MongoDB Atlas if…

you want a free tier to start, and MongoDB Atlas Fully managed cloud NoSQL database with flexible scaling, global distribution, and strong developer tooling.

MongoDB Atlas review & pricing

Frequently Asked Questions

Is Convex better than MongoDB Atlas?⌄

Both are solid database options. Convex is cheaper to start, but the right choice depends on the specific features and integrations you need.

What is the difference between Convex and MongoDB Atlas?⌄

Convex — Reactive backend-as-a-service with a built-in database, real-time queries, serverless functions, and AI-powered app generation. MongoDB Atlas — Fully managed cloud NoSQL database with flexible scaling, global distribution, and strong developer tooling. Both are database tools; the comparison table above breaks down pricing, free tiers, and what each is best for.

Convex vs MongoDB Atlas: which is cheaper?⌄

Convex pricing: Free · paid from $25/mo. MongoDB Atlas pricing: Free · paid from $30/mo. Confirm current pricing on each tool's official site, as plans change.

See more options in our guide to the best database tools for startups.

Still not sure which to pick?

Get a free, AI-powered tech stack — including the best database pick for your budget and team — in 60 seconds.

Build my stack free