MongoDB is our database of choice when a project's data genuinely doesn't fit a fixed relational schema — variable job records, evolving form structures, fast-changing product data. We've used it in production behind Node.js and NestJS backends.
MongoDB isn't our default database — PostgreSQL is. We reach for MongoDB specifically when the data itself is the reason: variable structure, rapid schema evolution, or document-shaped records that don't map cleanly to tables.
Job records, form submissions, or product catalogues where different entries legitimately carry different fields. Forcing that into rigid tables adds complexity MongoDB avoids by design.
Platforms where operational data (job records, integrations, statuses) evolves faster than a migration-heavy relational schema comfortably allows.
Early-stage products where the data model is still being discovered. A flexible document store reduces the migration overhead of frequent schema changes during that phase.
Application settings, feature flags, and structured-but-varied content where document storage maps more naturally to how the application actually reads and writes it.
PostgreSQL is our default database for most projects. MongoDB gets chosen deliberately, when the data itself argues for a document model — not because it's trendier.
Documents can carry different fields without a migration. That's genuinely useful for variable data — and genuinely risky if used as an excuse to skip data modelling entirely. We still design a schema; MongoDB just doesn't force us to migrate it every time it evolves.
When a "record" is naturally a self-contained JSON-like object — an order with line items, a form submission with dynamic fields — a document maps to it more directly than several joined tables.
Sharding is a first-class feature, not a bolt-on. For write-heavy, high-volume collections, that matters — though most projects we build never actually need it at their scale.
Mongoose gives you schema validation and structure on top of MongoDB's flexibility, closing most of the gap with a relational ORM while keeping the document model's benefits.
We build with both, and we'll recommend based on your actual data — not a default preference. Here's the honest breakdown.
MongoDB is one piece of a larger backend. Here's what we typically build around it.