Should I use PostgreSQL for an app that may need to scale globally later?

Yes — PostgreSQL is a very solid default choice, even if you may need to scale globally later.

Why it’s a good choice

• Reliable and mature: great data integrity, strong transactions, and proven at large scale.
• Flexible: works well for most product apps, from MVP to serious production systems.
• Good ecosystem: excellent tooling, extensions, and cloud support.
• Can scale quite far: with read replicas, partitioning, caching, connection pooling, and careful schema design, Postgres can handle a lot.

The global-scaling caveat

If you expect multi-region, low-latency writes across continents, PostgreSQL by itself becomes more complex because:

• standard Postgres is primarily single-writer
• cross-region replication introduces latency and consistency tradeoffs
• active-active global writes are not its native strength

Practical recommendation

Use PostgreSQL if:

• you’re building an MVP or v1
• your app has normal business/product requirements
• you want to optimize for speed of development and correctness

Plan for global scale by:

• designing for stateless app servers
• using caching/CDNs
• keeping data access patterns clean
• considering read replicas and regional read scaling later
• isolating parts of the system that may need special global handling

When to consider something else

If you already know you need:

• global writes with very low latency
• multi-region active-active
• massive horizontal scale from day one

then you might look at:

• distributed SQL databases like CockroachDB, YugabyteDB
• cloud-managed globally distributed options like Spanner or Cosmos DB depending on your cloud and consistency needs

Bottom line

For most apps: yes, use PostgreSQL.
It’s usually the best balance of speed, simplicity, and future scalability.
If global scale becomes real later, you can solve that with architecture changes or, if needed, migrate specific workloads to a more distributed system.

If you want, I can help you choose between PostgreSQL vs CockroachDB vs Spanner based on your expected traffic and consistency needs.