Back-End Engineer (Database): choose the right database type for a mobile app

Cartora is a fast-growing e-commerce startup focused on delivering personalized online shopping experiences. The company’s web platform, powered by MySQL 8.0 and hosted on AWS, has achieved impressive growth, handling millions of users and managing high-traffic events with advanced caching and real-time data streaming. As Cartora prepares to launch a mobile app, new challenges arise: the app must efficiently process both structured and unstructured data—like user reviews and product images—while scaling to meet surges in user activity. Competitors have adopted NoSQL solutions for similar needs, but Cartora’s team is primarily experienced with MySQL, making the choice of database architecture a critical decision that will impact scalability, performance, and the company’s competitive edge.

You step into the role of a Junior Backend Developer at Cartora, tasked with helping decide the best database solution for the company’s upcoming mobile app. In a one-on-one technical meeting with the Tech Lead, you’ll analyze the pros and cons of MySQL and MongoDB, focusing on factors like scalability, consistency, schema flexibility, and your team’s expertise. You’ll ask clarifying questions, discuss trade-offs, and present your recommendation—defending your reasoning as the Tech Lead challenges your assumptions and probes for detailed justifications. Your goal is to align your technical advice with Cartora’s business needs and operational constraints.

• Demonstrate your understanding of SQL and NoSQL database trade-offs in conversation with the Tech Lead.
• Clearly communicate your technical reasoning and respond to follow-up questions.
• Provide a well-supported recommendation that addresses Cartora’s requirements and constraints.
• Identify and discuss potential risks and how they could be managed.