MongoDB

When to Use

• MongoDB database operations
• Document-based data modeling
• Aggregation pipelines
• Semi-structured or polymorphic data that varies per record
• Rapid prototyping where schema flexibility accelerates iteration
• Event logging, IoT telemetry, or content management systems

When NOT to Use

• Relational-heavy data models with complex joins and foreign key constraints
• SQL-only projects where the entire stack is built around relational databases
• Simple key-value storage where Redis or a lightweight store is more appropriate
• Financial systems requiring multi-table ACID transactions as the norm