2–5 years · Mid — Node.js · Express · MongoDB · React · REST APIs · Authentication
Analyses current component structure and API responses; retrieves additional fields from the backend; ensures backward compatibility for existing users; implements lazy loading for new data; tests to confirm no degradation in performance.
The new data fields change frequently. How would you ensure the component remains adaptable to future changes?
Considers the access patterns, ensuring frequent queries can be optimised; mentions embedding comments if they are always accessed with the post; discusses referencing if comments are large or needed independently; evaluates trade-offs in data duplication and consistency; considers future scalability.
What would change if comments needed to be updated frequently?
Implements a refresh token strategy where the access token is short-lived while the refresh token has a longer lifespan; stores refresh tokens securely, ideally in HttpOnly cookies; uses a secure endpoint to exchange refresh tokens for new access tokens; considers revocation strategies for compromised tokens.
What measures would you take to mitigate the risk of token theft?
Identifies the service or database migrated and reasons for the migration; discusses specific technical challenges faced, such as downtime or data integrity; describes how the migration was tested and validated; mentions lessons learned and improvements made post-migration; avoids blaming external factors for issues encountered.
What would you do differently in future migrations?
Defines clear resource-oriented endpoints like /products, /products/{id}, using HTTP methods appropriately; includes pagination and filtering for /products; implements versioning in the URL (e.g., /v1/products) to avoid breaking changes; emphasises proper status codes for different response scenarios.
How would you handle changes to the data structure without breaking existing clients?
Utilises virtualisation libraries like react-window or react-virtualized to only render visible items; leverages memoisation with React.memo or useMemo for expensive components; checks for unnecessary re-renders using React DevTools; suggests pagination for managing large data sets.
If virtualisation isn't an option, what else could you try?
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