Convex vs PostgreSQL for Solo Developers

Quick Comparison

Convex Overview

Convex is a backend platform where your database, server functions, file storage, and realtime sync all live under one roof. You write TypeScript functions that run on Convex's servers, and the platform automatically keeps every connected client in sync when data changes. No WebSocket code, no manual cache invalidation, no API routes to maintain.

For solo developers, Convex collapses the entire backend into a set of functions. Your schema defines types that propagate through your functions into your React components. The development experience is smooth: change a mutation, see the effect in your running app immediately.

The free tier gives you 1 million function calls, 1 GB database storage, and 1 GB file storage per month. That covers the build phase and early users comfortably.

PostgreSQL Overview

PostgreSQL is the most advanced open-source relational database. It supports standard SQL along with JSON columns, full-text search, PostGIS for geospatial data, materialized views, CTEs, window functions, and a long list of features that other databases are still catching up on. It has been in active development since 1996 and it shows.

For solo developers, Postgres is the default choice for a reason. It works with every language, every framework, and every deployment model. You can self-host it, use managed services like Neon (free tier), Supabase (free tier), Railway ($5/mo), or AWS RDS. The tooling ecosystem is the largest of any database.

Postgres is free and open source with no usage limits. A solo developer can run it on a $5 VPS and handle thousands of concurrent users without paying for a managed service.

Head-to-Head Comparison

When to Pick Convex

Pick Convex when you are building a React application and the development experience matters more to you than long-term flexibility. Convex's tight integration with React makes building interactive, realtime applications feel effortless. You write functions, call hooks, and everything stays in sync.

It is the right choice when your application is inherently realtime. Collaborative document editors, multiplayer games, live auction platforms, team chat tools: these applications need every user to see the same state simultaneously. Convex makes this the default behavior rather than a feature you build.

Choose Convex when you are prototyping or validating an idea quickly. The time savings of not building an API layer can be the difference between launching this week and launching next month. For a solo developer testing product-market fit, that speed matters.

When to Pick PostgreSQL

Pick PostgreSQL when you want the most capable, flexible, and portable database available. Postgres handles relational data, JSON data, full-text search, geospatial queries, time-series data, and vector embeddings (via pgvector). Whatever your application needs, Postgres probably has a feature for it.

It is the right choice when your data model is complex and relational. If you need to join five tables, aggregate data across millions of rows, or enforce complex referential integrity, SQL is the tool for the job. No document database can match the query power of a well-designed Postgres schema.

Choose PostgreSQL when vendor independence is important. Your data lives in a standard database that any tool can connect to. You can switch hosting providers, change ORMs, rebuild your entire backend in a different language, and your database stays exactly the same.

PostgreSQL is also the right choice when you are building something that needs to last. Postgres has been reliable for 30 years. The community is enormous. The documentation is comprehensive. And your skills transfer to any company or project that uses it, which is most of them.

The Verdict

This is a choice between speed of development and breadth of capability.

Convex gets you to a working product faster if you are building a React application with realtime features. The platform handles backend concerns that would take weeks to build yourself. The trade-off is vendor lock-in and a smaller feature set compared to Postgres.

PostgreSQL gives you the most powerful database available with zero lock-in. The trade-off is that you need to build your own API layer, handle realtime yourself (or use Supabase), and manage more infrastructure.

For most solo developers, I would recommend starting with PostgreSQL through a managed service like Neon or Supabase. Both have free tiers, both work with Drizzle or Prisma for type-safe queries, and Supabase even adds realtime subscriptions and auth on top. This gives you a similar development speed to Convex while keeping your data in a standard database.

If you specifically want the Convex development experience and you are building a React app where automatic reactivity saves you significant time, Convex is worth trying. Just go in knowing that your backend code and data model are tied to the platform.