Hi @Rajkamal Singh Jhala ,

From my experience, interviews usually focus on practical experience rather than definitions.

Scenario-based questions might include processing large datasets, securing data, handling integrations or designing reusable functionalities. 

Be prepared to discuss a real project, the challenges you faced, how you solved them, and the reasoning behind your decisions.

Hi @Rajkamal Singh Jhala ,

If I were interviewing a 2+ year OutSystems developer, I'd focus most on:

SQL → Exception Handling → REST API → Aggregates → Lists → Timers → Performance → Security → Data Modeling → Real-world scenarios

The interviewer is much more likely to ask “How would you implement this?” / “What happens if this fails?” / “How would you optimize this?” than simply “What is an Aggregate?”.

Here are the key areas I would recommend preparing:

1. SQL & Database

• Complex queries & Joins (1:1, 1, M)
• Aggregates vs Advanced SQL
• Query optimization & Indexing
• Pagination & Large datasets
• Transactions & Bulk operations
• Stored Procedures
• Duplicate & NULL handling

2. Data Modeling

• Entity design for real-world scenarios
• 1:1, 1, M relationships
• Junction entities
• Reference vs Identifier
• Delete rules & Indexing
• Normalization / Denormalization
• Audit & Historical data

3. Exception Handling

• Exception Handler & Custom Exceptions
• Exception propagation
• Rollback / Transactions
• Handling exceptions in loops
• API & Database exceptions
• Logging & meaningful error handling
• Avoiding swallowed exceptions

4. REST API / Integration

• Consume / Expose REST APIs
• HTTP status codes
• Authentication & OAuth
• Request/Response & JSON mapping
• Timeout & Retry mechanisms
• Idempotency
• Pagination & File handling
• API failure handling

5. Client vs Server Logic

• Client Action vs Server Action
• Minimizing server calls
• Client/Server data handling
• Validation
• Screen state & Refresh logic

6. Lists & Aggregates

• List manipulation & ListAppend
• Filtering / Sorting / Mapping
• Duplicate handling
• Multiple joins & Dynamic filters
• Group By / Aggregations
• Large List processing
• Aggregate optimization

7. Timers & Background Processing

• Batch processing
• Large-volume processing
• Retry & failure handling
• Idempotent Timers
• Concurrent execution
• Avoiding duplicate processing
• Recovery mechanisms

8. Performance

• Slow screen / Aggregate / API troubleshooting
• Database optimization
• Large data handling
• Client-server communication
• Monitoring & production troubleshooting

9. Security

• Roles & Authorization
• Server-side validation
• API security
• SQL Injection / XSS
• Authentication vs Authorization
• Sensitive data handling

10. Reactive UI

• Form & Dynamic validation
• Parent/Child communication
• Screen lifecycle
• Multiple data sources
• Refresh & state management

11. Architecture

• Layered architecture
• Core / Service / UI responsibilities
• Reusability
• Dependency management
• Circular dependencies
• Coupling / Cohesion
• Refactoring

12. Real-World ScenariosFocus especially on implementation scenarios such as:

• Processing 20K+ records efficiently
• Handling API failures and retries
• Preventing duplicate Timer processing
• Handling concurrent updates
• Optimizing a screen loading thousands of records
• Implementing audit/history
• Designing scalable integrations
• Troubleshooting production performance issues