IntermediateBEHAVIORAL
Describe a debugging incident where a bug required you to trace through both frontend and backend layers (for example, incorrect data rendering due to API or serialization issues). How did you isolate the root cause and verify the fix across the stack?
Full Stack Developer
General

Sample Answer

Situation: At my last role, an order dashboard in React showed incorrect totals for ~15% of customers after a deployment. Task: I needed to trace the issue across React, our Node.js/Express API, and a PostgreSQL backend. Action: I first captured the network payload in Chrome DevTools and noticed missing fields compared to the TypeScript types. I then added structured logging and reproduced the request in Postman, confirming the API was returning rounded values. In the Node layer, I found a new JSON serializer that incorrectly cast DECIMAL to FLOAT, causing precision loss. I updated the serializer to return strings, adjusted the React type definitions and formatting logic, and added contract tests using Pact plus Jest integration tests. Result: Data discrepancies dropped to 0%, support tickets for billing issues fell by 40%, and we added regression tests that caught a similar bug three months later before release.

Keywords

Use browser DevTools and API tools to compare frontend expectations with backend responsesAdd targeted logging and reproduce the issue via direct API callsIdentify and fix serialization/typing mismatch, then align types across layersVerify with automated tests (contract, integration) and monitoring after deployment
Related Questions

Walk me through a recent multi-channel digital marketing campaign you managed end-to-end. How did you set objectives, choose channels, allocate budget, and measure success?

IntermediateBEHAVIORAL

In your resume you note improving or optimizing [a process, KPI, or metric]. What specific baseline metrics did you start from, what steps did you personally take, and how did you verify that the improvement was due to your changes rather than external factors?

IntermediatePROBLEM_SOLVING

Based on your hydrology and irrigation engineering background, explain how you would estimate the irrigation water requirement for a kharif crop in a semi-arid region of Gujarat. Walk me through each step: from reference evapotranspiration estimation, crop coefficient selection, effective rainfall calculation, to arriving at canal discharge for a given command area.

IntermediateTECHNICAL

In your civil engineering studies, what specific design coursework or project work did you complete related to irrigation channels or canals (e.g., design of lined/unlined canals, distributaries, minors)? Describe one such design in detail, including how you determined discharge, permissible velocity, section dimensions, and lining choice for Gujarat-type soil and climate conditions.

IntermediateTECHNICAL

On your resume you mention working on a cross-functional project (e.g., involving multiple teams or stakeholders). Describe a situation from that project where priorities conflicted—how did you navigate the trade-offs and what was the final outcome?

IntermediateSITUATIONAL