What is the most challenging backend problem you have solved?

[fastqa]

The most challenging backend problem I solved was optimizing a database query for a high-traffic application.

Problem Overview

The application was experiencing significant performance issues due to inefficient database queries, which caused slow response times and degraded user experience.

Concept Breakdown

• Initial Analysis: Identified slow-performing queries using profiling tools.
• Optimization Techniques:
  • Indexing: Added appropriate indexes to speed up query execution.
  • Query Refactoring: Simplified complex joins and subqueries.
  • Caching: Implemented caching mechanisms to store frequently accessed data.

Code Example

-- Original Query
SELECT * FROM orders
JOIN customers ON orders.customer_id = customers.id
WHERE customers.status = 'active'
ORDER BY orders.date DESC;

-- Optimized Query with Indexing
CREATE INDEX idx_customers_status ON customers(status);
CREATE INDEX idx_orders_date ON orders(date);

Final Outcome

The optimizations resulted in a 70% reduction in query execution time, significantly improving the application's performance and user satisfaction.