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Your agent handles concurrent requests, but they share a single rate-limited API key and randomly hit limits under load.
How would you design the system to share a rate-limited resource fairly across concurrent requests?
General Medium

Answer:

  1. Centralize rate limiting: Track usage against the shared limit in one place, so concurrent requests coordinate.

  2. Use a token bucket: Meter access with an atomic limiter, so the limit is respected under concurrency.

  3. Queue when at the limit: Hold requests rather than failing, so bursts drain smoothly.

  4. Allocate fairly: Prevent one request stream from monopolizing the key, so all get access.

  5. Add capacity when needed: Use multiple keys or providers for sustained load, so the shared limit isn't a hard ceiling.

Your agent works, but your evaluation runs take an hour, so developers skip them and quality regressions slip through.
How would you design evaluation to be fast enough that developers actually run it?
General Medium

Answer:

  1. Tier your eval suite: Run a fast core set on every change and the full suite less often, so quick feedback is always available.

  2. Parallelize eval runs: Execute cases concurrently, so wall-clock time drops.

  3. Cache eval results: Skip re-running unchanged cases, so only affected ones rerun.

  4. Sample for quick checks: Use a representative subset for fast iteration, so developers get signal in seconds.

  5. Integrate into the workflow: Run evals automatically in CI, so they aren't a manual step to skip.

Your agent's LLM calls occasionally hang indefinitely, and without a timeout, they tie up resources and block the request.
How would you design the system to handle hanging LLM calls?
General Medium

Answer:

  1. Set aggressive timeouts: Bound every call just above expected latency, so hangs are cut off fast.

  2. Retry on a different path: Reissue timed-out calls to another provider or replica, so recovery is quick.

  3. Use streaming to detect stalls: Watch for token flow stopping, so hangs are caught mid-stream.

  4. Release resources on timeout: Free connections and memory when a call is abandoned, so hangs don't leak.

  5. Alert on hang patterns: Track timeout frequency, so systemic issues surface.

Your agent processes documents into chunks, but tables and code blocks get split across chunk boundaries and become unreadable.
How would you design chunking to preserve structured content?
General Medium

Answer:

  1. Detect structural elements: Identify tables, code, and lists, so they can be handled specially.

  2. Keep structures intact: Never split a table or code block across chunks, so they stay readable.

  3. Chunk on semantic boundaries: Split at natural section breaks, so content stays coherent.

  4. Attach context to structures: Include surrounding headers with a table or code, so it's interpretable alone.

  5. Handle oversized structures: Split very large structures sensibly, so they fit while staying usable.

Your agent embeds documents at ingestion, but re-embedding your whole corpus for a model upgrade would take days and cost a fortune.
How would you design the system to handle embedding model migrations efficiently?
General Medium

Answer:

  1. Migrate incrementally: Re-embed in batches over time, so the cost and load spread out.

  2. Dual-index during transition: Serve from the old index while building the new, so there's no downtime.

  3. Prioritize hot content: Re-embed frequently-retrieved documents first, so quality improves fastest where it matters.

  4. Never mix embedding versions: Keep queries and documents on the same model, so retrieval stays valid.

  5. Cut over atomically: Switch to the new index once complete, so there's a clean transition.

Your agent's prompt-caching saves cost, but a small dynamic value near the top of the prompt is invalidating the entire cache.
How would you design the prompt to maximize cache hits?
General Medium

Answer:

  1. Move dynamic content late: Put variable data after static content, so the cacheable prefix stays stable.

  2. Order by volatility: Arrange from most to least stable, so more of the prompt caches.

  3. Separate the variable value: Isolate the dynamic bit so it doesn't break the prefix, so caching holds.

  4. Cache the stable prefix: Explicitly mark the static portion for caching, so it's reused.

  5. Measure cache hit rate: Track how often the cache hits, so prompt structure can be tuned.

Your agent streams responses, but when a tool call happens mid-stream, the user sees the stream freeze with no explanation.
How would you design the system to handle tool calls gracefully during streaming?
General Medium

Answer:

  1. Signal tool activity: Show a status indicator during tool calls, so the freeze is explained.

  2. Stream around the call: Continue streaming text before and after, so the pause is minimal.

  3. Parallelize where possible: Start tool calls early, so their latency overlaps with generation.

  4. Set tool timeouts: Bound tool calls, so the stream doesn't hang indefinitely.

  5. Fall back on failure: Continue with a degraded response if the tool fails, so the stream completes.

Your agent uses function calling, but the model sometimes returns arguments that don't match the schema, causing runtime exceptions.
How would you design the system to guarantee schema-valid function arguments?
General Medium

Answer:

  1. Use constrained generation: Enforce the schema at decode time where supported, so invalid args can't be produced.

  2. Validate before executing: Check arguments against the schema, so bad ones are caught pre-execution.

  3. Re-prompt on failure: Return the validation error to the model, so it corrects.

  4. Coerce where safe: Fix minor type mismatches automatically, so trivial errors don't fail.

  5. Provide clear schemas: Give precise types and examples, so the model produces valid args more often.

Your agent's vector search returns results in milliseconds, but the reranking step you added takes 800ms and dominates latency.
How would you design the system to keep reranking fast?
General Medium

Answer:

  1. Shrink the candidate set: Rerank a small shortlist, not hundreds, so the reranker does less work.

  2. Use a lighter reranker: Pick a smaller cross-encoder where quality allows, so latency drops.

  3. Batch on GPU: Score candidates in one batched pass, so you exploit parallelism.

  4. Cache rerank scores: Reuse rankings for repeated queries, so you skip recomputation.

  5. Rerank conditionally: Skip it when first-stage confidence is high, so you pay only when needed.

Your agent is mature, but you realize the team optimizes for what's easy to measure rather than what actually matters most.
How would you design the process to keep focus on what matters over what's measurable?
General Medium

Answer:

  1. Name what matters most: Explicitly define the highest-value goals, so they aren't crowded out by easy metrics.

  2. Measure the important, even if hard: Invest in measuring what matters, so it isn't neglected for convenience.

  3. Use qualitative signals: Supplement metrics with judgment where measurement is hard, so the important is tracked.

  4. Weight priorities deliberately: Rank work by real value, not measurement ease, so focus stays right.

  5. Guard against measurement bias: Watch for drift toward the easily-measured, so priorities stay honest.

Your agent needs to handle a request where the user's stated preference conflicts with what their behavior suggests they actually want.
How would you design the system to handle stated-versus-revealed preference conflicts?
General Medium

Answer:

  1. Notice the conflict: Detect when stated and revealed preferences diverge, so it's not ignored.

  2. Default to stated preferences: Honor what the user explicitly says, so you respect their agency.

  3. Surface the discrepancy: Point out the apparent conflict, so the user can reconcile it.

  4. Ask which to follow: Clarify when the conflict matters, so you don't guess wrong.

  5. Adapt as they clarify: Adjust based on their response, so you serve their true preference.

Your agent works, but it can't recognize when the right response to a request is to question whether it should be done at all.
How would you design the system to question questionable requests constructively?
General Medium

Answer:

  1. Recognize questionable requests: Detect when a request warrants a second look, so it's not blindly executed.

  2. Raise concerns constructively: Voice the issue helpfully, so the user isn't lectured.

  3. Explain the reasoning: Show why you're questioning it, so the concern is credible.

  4. Respect user autonomy: Proceed if they still want to after being informed, so you don't override them.

  5. Decline only genuine harms: Refuse only when doing it would clearly cause serious harm, so you don't over-refuse.

Your agent needs to handle a request where the user wants speed, but the task genuinely can't be done well quickly.
How would you design the system to handle irreducible time requirements honestly?
General Medium

Answer:

  1. Set honest expectations: Tell the user the task genuinely takes time, so they aren't misled.

  2. Explain why: Show what makes it irreducibly slow, so the timeline is credible.

  3. Offer a fast partial: Provide what can be done quickly, so users get some immediate value.

  4. Don't fake speed with quality loss: Avoid rushing into a bad answer, so quality holds.

  5. Move slow work to background: Run it async and notify on completion, so users aren't blocked waiting.

Your agent works, but it can't tell when a user's satisfaction with an answer is a sign it was actually wrong in a way they'll discover later.
How would you design the system to avoid satisfying users with wrong answers?
General Medium

Answer:

  1. Prioritize correctness over approval: Aim for right answers, not just satisfying ones, so users aren't pleased into error.

  2. Ground answers in evidence: Base them on real support, so satisfaction rests on accuracy.

  3. Verify before delivering: Check answers for correctness, so satisfying-but-wrong ones are caught.

  4. Flag uncertainty honestly: Don't project false confidence to please, so users aren't misled.

  5. Measure outcomes, not just satisfaction: Track whether answers actually worked, so pleasing-but-wrong ones surface.

Your agent needs to handle a request where the user wants reassurance, but honest assessment would be more valuable.
How would you design the system to balance reassurance against honest assessment?
General Medium

Answer:

  1. Prioritize honesty: Give the accurate assessment, so users aren't falsely reassured.

  2. Deliver with empathy: Acknowledge the user's feelings, so honesty isn't cold.

  3. Reassure where genuinely warranted: Offer real reassurance when it's true, so support is authentic.

  4. Provide constructive next steps: Show what they can do, so honesty is actionable, not just deflating.

  5. Don't substitute comfort for truth: Avoid empty reassurance, so the assessment stays valuable.

Your agent works, but it can't recognize when its answer, though correct, will be acted on in a way that causes harm.
How would you design the system to consider the consequences of how answers are used?
General Medium

Answer:

  1. Anticipate use: Consider how the answer will be acted on, so foreseeable harm is caught.

  2. Flag risky applications: Warn when acting on the answer could cause harm, so users are aware.

  3. Add necessary safeguards: Include caveats or conditions for safe use, so harm is mitigated.

  4. Withhold genuinely dangerous help: Decline when use would clearly cause serious harm, so you don't enable it.

  5. Right-size the caution: Don't over-warn on benign answers, so caution stays proportionate.

Your agent needs to handle a request where the most useful response depends on whether the user is exploring or executing.
How would you design the system to distinguish exploration from execution mode?
General Medium

Answer:

  1. Detect the mode: Recognize whether the user is exploring possibilities or executing a plan, so you respond right.

  2. Support exploration broadly: Offer options and considerations when exploring, so they can range.

  3. Support execution precisely: Give concrete, actionable steps when executing, so they can act.

  4. Adapt as it shifts: Switch modes when the user moves from exploring to doing, so you stay aligned.

  5. Confirm when ambiguous: Clarify the mode if unclear, so you serve the right one.

Your agent works, but it can't tell when giving a direct answer versus teaching the user to find it themselves is more valuable.
How would you design the system to choose between answering and teaching?
General Medium

Answer:

  1. Read the user's goal: Judge whether they want the answer or the skill, so you serve the real need.

  2. Answer directly when that's wanted: Give the result when speed and outcome matter, so you don't over-teach.

  3. Teach when capability matters: Show the method when learning serves them, so they grow.

  4. Do both when useful: Provide the answer and the how, so both needs are met.

  5. Let users signal: Allow them to ask for one or the other, so you don't guess.

Your agent needs to handle a request where it must decide how much to trust the user's own stated expertise.
How would you design the system to calibrate to user-claimed expertise?
General Medium

Answer:

  1. Take claims as a starting point: Use stated expertise to set initial depth, so you meet users where they say they are.

  2. Verify through interaction: Adjust based on how they respond, so claims are validated in practice.

  3. Adapt if the claim seems off: Recalibrate when responses don't match stated expertise, so you fit reality.

  4. Avoid condescension or overshooting: Neither talk down to nor over-assume, so the level fits.

  5. Let users recalibrate: Allow them to signal too basic or too advanced, so matching corrects.

Your agent is mature, but you're realizing that the way you measure its success shapes its behavior in ways you didn't intend.
How would you design the process to ensure metrics drive intended behavior?
General Medium

Answer:

  1. Anticipate metric incentives: Consider what behavior a metric will encourage, so you avoid perverse incentives.

  2. Watch for gaming: Detect when the system optimizes the metric at the expense of real value, so distortion is caught.

  3. Use balanced metrics: Combine measures so no single one can be gamed harmfully, so behavior stays aligned.

  4. Tie metrics to real goals: Ensure metrics proxy actual value, so optimizing them serves the intent.

  5. Revise metrics that misdirect: Change measures that drive wrong behavior, so incentives stay right.