Sample Answer
(S) At a previous company, our public payments API was being hammered by a few misconfigured clients, degrading service for others. (T) I had to design and implement a rate-limiter that enforced per-API-key quotas while keeping latency under 10 ms for the check. (A) I proposed a token-bucket–style rate limiter using Redis as a centralized, in-memory store. Each API key had a bucket with capacity and refill rate (e.g., 100 requests/min). On each request, a Lua script executed atomically in Redis to decrement tokens and return whether the request was allowed. For burst handling, I allowed short spikes up to 2x the steady rate. I also added a global safety cap per IP to mitigate abuse. We exposed remaining quota via custom headers so clients could self-throttle. (R) The rate limiter added ~3–5 ms P95 latency, and we reduced 429-related support tickets by ~60% within a month. Peak traffic became much smoother, with a ~25% reduction in CPU spikes on the API nodes and no further outages due to client misbehavior.
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?
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?
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.
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.
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?