Technical practice
Optimizing MoE Model Inference
What to coverDiscuss the specific challenges of serving large Mixture-of-Experts (MoE) models, particularly regarding memory bandwidth and expert routing. Explain how you would approach tiered caching or disaggregation to improve throughput for these architectures.
Agentic Workload Characteristics
What to coverHow do agentic workloads differ from traditional request-response LLM inference in terms of traffic patterns and latency requirements? Suggest system-level optimizations to handle the non-linear, multi-step nature of agentic tasks.
Performance Measurement Methodology
What to coverDescribe your process for defining performance metrics before optimizing a serving stack. Explain how you distinguish between latency, throughput, and cost-per-token, and how you validate that a performance improvement is statistically significant.
vLLM and SGLang Internals
What to coverCompare the architectural approaches of vLLM and SGLang regarding memory management and request scheduling. Discuss how you would extend or modify these frameworks to support custom hardware or specific production requirements.
C++ and Python Integration in Systems
What to coverIn high-performance inference systems, how do you decide which components to implement in C++ versus Python? Provide an example of how you manage the boundary between high-level orchestration and low-level compute kernels.
Distributed Serving Trade-offs
What to coverWhen scaling inference across multiple nodes, what are the primary bottlenecks in communication and synchronization? Discuss the trade-offs between model parallelism strategies like tensor parallelism versus pipeline parallelism.
System-Level Disaggregation
What to coverExplain the concept of disaggregated inference systems and the benefits of separating compute from memory. What are the potential pitfalls of this architecture in a production environment, and how would you mitigate them?
Bridging Research to Production
What to coverDescribe a scenario where a promising research idea failed to perform as expected on a real-world production fleet. How did you diagnose the discrepancy, and what adjustments were necessary to make the system viable?
Behavioural practice
Collaborating with Platform Teams
What to coverDescribe a situation where you had to integrate a research-driven solution into an existing production stack owned by another team. How did you manage technical disagreements and ensure the stability of the production environment?
Handling Ambiguity in Research
What to coverTell me about a time you had to decide whether to pursue a research direction or pivot based on changing project requirements. What criteria did you use to evaluate the potential impact versus the engineering effort?
Communicating Technical Limitations
What to coverGive an example of when you had to explain to stakeholders that a proposed optimization would not yield the expected results. How did you use data to support your position and maintain alignment with the project goals?
Driving Open-Source Contributions
What to coverDescribe your experience contributing to or maintaining open-source inference projects. How do you balance the need for proprietary internal features with the goal of contributing back to the community?