Frequently Asked Questions

A tech stack is the combination of technologies used to build and run an application. It typically covers the frontend (what users see), the backend (server-side logic), the database (data storage), and infrastructure (hosting and deployment). Choosing the right stack affects how fast you can ship, how easy it is to hire, and how well your product scales.

For most early-stage startups, a strong default is Next.js, TypeScript, PostgreSQL, and Vercel. This combination gives you fast iteration, full-stack TypeScript, a battle-tested database, and zero-config deployment. If your startup is primarily mobile, React Native with Expo is the most practical cross-platform option. See the full breakdown in the tech stack for startups guide.

For an MVP, prioritize speed over perfection. A backend-as-a-service like Supabase or Firebase combined with a React or Vue frontend removes the need to build auth, a database API, and storage from scratch. If you are a solo developer, a managed platform like Supabase with Next.js gives you auth, database, and storage in one integration. The goal of an MVP stack is to validate your idea before optimizing your infrastructure.

The most common SaaS stack in 2026 is Next.js, TypeScript, PostgreSQL (via Neon or Supabase), Clerk for auth, and Stripe for billing, deployed on Vercel. This covers everything a subscription product needs: server-side rendering for SEO, type-safe full-stack code, a relational database for multi-tenant data, drop-in auth with organization support, and a reliable billing API.

If you want to target both iOS and Android with one codebase, React Native with Expo is the most practical option. It shares logic and components across platforms and has strong community support. For performance-critical apps like games or maps, Flutter is a strong alternative with faster rendering. If your team is mobile-first and you can afford separate codebases, native Swift for iOS and Kotlin for Android will give you the best platform integration.

For AI applications that rely heavily on LLM APIs, vector databases, and ML pipelines, Python is the most practical backend language because most AI libraries are Python-first. A common AI app stack is FastAPI for the backend, React or Next.js for the frontend, PostgreSQL with pgvector for semantic search, and either Vercel or Railway for deployment. If you are building a lightweight AI wrapper product, a TypeScript stack with Vercel AI SDK works well.

Next.js is the leading full-stack React framework and has a larger ecosystem, more templates, and broader community support. Nuxt is the Vue equivalent and offers a comparable developer experience with excellent defaults for SSR and static generation. The practical difference comes down to team preference: React developers should use Next.js, Vue developers should use Nuxt. Both are production-grade choices. If you are starting fresh with no preference, Next.js has a larger hiring pool.

Supabase is built on PostgreSQL and uses SQL, which makes it easier to model relational data and run complex queries. Firebase uses NoSQL (Firestore) and is optimized for real-time sync and mobile-first apps. Supabase is open-source and can be self-hosted; Firebase is a fully managed Google service. For most web applications with structured data, Supabase is the stronger default. For mobile apps that need offline sync and real-time updates out of the box, Firebase is easier to set up.

Clerk is designed for modern React and Next.js applications with pre-built UI components, organization support, and a developer-friendly dashboard. Auth0 is more enterprise-focused, offers more configuration options, and supports more complex identity scenarios like custom flows and legacy system integration. For startups and indie projects, Clerk is faster to set up and has a more generous free tier. For enterprise applications with strict compliance requirements, Auth0 gives you more control.

Vercel is purpose-built for Next.js and has the best integration with the React ecosystem, including edge functions, image optimization, and seamless preview deployments. Netlify supports a wider range of frameworks and has a stronger plugin ecosystem for static sites. For Next.js projects, Vercel is the default choice. For static sites, JAMstack projects, or projects using Astro, SvelteKit, or Gatsby, Netlify is equally capable and sometimes more cost-effective.

PostgreSQL is a relational database that stores data in structured tables with schemas. It excels at complex queries, joins, and data consistency. MongoDB is a document database that stores JSON-like documents without a fixed schema. It is more flexible for evolving data shapes. For most application backends with structured domain models, PostgreSQL is the safer long-term choice. MongoDB is a practical fit when your data is naturally document-shaped, such as content management, product catalogs, or event logs.

MERN stands for MongoDB, Express.js, React, and Node.js. It is a full-stack JavaScript stack that was popular in the 2015-2020 era. All four layers use JavaScript or JSON, which reduces context-switching. Today, many MERN-style projects have evolved: Express is often replaced by Next.js API routes, and MongoDB is sometimes swapped for PostgreSQL with Prisma. The MERN stack is still a valid choice for teams already familiar with it, but newer full-stack frameworks like Next.js simplify the architecture.

The fastest way to learn a new stack is to build a small project with it from start to deployment. Reading documentation is useful but hands-on building locks in the knowledge. Pick a simple CRUD application — a to-do app, a blog, or a notes tool — and implement it end to end including auth, a database, and deployment. Once you have shipped one small project, you will understand where the stack is strong and where it requires workarounds. Use the roadmaps on this site to understand the learning order for specific stacks.

A full-stack developer needs to be comfortable with HTML, CSS, and JavaScript on the frontend; a server-side language (Node.js, Python, Ruby, or similar) on the backend; a relational database like PostgreSQL; version control with Git; and basic deployment using a cloud platform or managed hosting. In practice, most full-stack roles in 2026 also expect familiarity with TypeScript, React, REST or GraphQL APIs, and CI/CD pipelines. You do not need to master every layer equally — depth in one area and working knowledge in others is the realistic standard.

A frontend developer builds the user interface: the HTML, CSS, and JavaScript that runs in the browser. A backend developer builds the server-side logic: APIs, databases, authentication, and business rules. A full-stack developer works across both layers. In small teams and startups, full-stack roles are common because one person can own a feature end to end. At larger companies, frontend and backend roles are often specialized so each developer can go deeper in their domain.