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Optiver·Software Engineer·Technical Phone Screen·Intermediate

Intermediate
May 2026

Summary

Optiver put me through a pretty intense cognitive exercise for a Software Engineer role, the kind where you're doing rapid-fire task switching and then immediately asked to articulate your own mental process. Not your typical coding screen.

Questions Asked (2)

Q1

You're given a stream of alternating stimuli (digits and colored shapes). For digits, respond with whether the digit is odd or even; for shapes, respond with the shape's color. Do this as fast and accurately as you can, then walk us through the exact mental strategies you used to reduce the cost of switching between tasks, avoid working memory interference, and bounce back from mistakes.

Adaptability & AmbiguityTechnical Trade-offs
Author's notes

This was genuinely weird to be asked in an interview.

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AI HintsAI Generated

Suggested Approach

First, complete the task as instructed, focusing on speed and accuracy. Then, in your walkthrough, describe the specific cognitive strategies you used to manage task switching, working memory, and error recovery, linking them to software engineering principles like context switching and error handling.

Pro tip: Emphasize that you treat the task like a system: you minimize context-switching overhead by batching similar stimuli when possible, and you use external cues (like the shape's color) to offload working memory. This shows you think about performance optimization even under pressure.

1. Acknowledge the task and set the stage

Briefly restate the task to show you understood it, and mention that you'll first perform it, then explain your mental strategies.

2. Describe task-switching strategies

Explain how you reduced switching costs, e.g., by grouping similar tasks, using external cues, or maintaining a consistent response mapping.

3. Explain working memory management

Detail how you avoided interference, such as by offloading information to the environment, using chunking, or repeating rules silently.

4. Discuss error recovery

Describe how you bounced back from mistakes, e.g., by quickly resetting attention, not dwelling on errors, and maintaining a steady pace.

5. Connect to software engineering

Relate your strategies to engineering concepts like context switching, caching, error handling, and performance optimization to demonstrate relevance.

Key Points to Mention

  • Task-switching cost and how to minimize it (e.g., batching, predictable patterns)
  • Working memory limitations and offloading techniques (e.g., visual cues, chunking)
  • Error recovery strategies (e.g., resetting, not ruminating, maintaining speed)
  • Relevance to software engineering: context switching, caching, error handling, performance under pressure
  • Self-monitoring and metacognition: being aware of your own cognitive processes
  • Adaptability: adjusting strategies on the fly based on performance

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.

Q2

Design a two-week practice plan to improve your reaction time and accuracy on this kind of task switching exercise, including specific drills, rest intervals, and how you'd measure progress.

Product Analytics & MetricsAdaptability & Ambiguity
Author's notes

I fumbled this more than the actual task.

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AI HintsAI Generated

Suggested Approach

Structure your answer like a mini-experiment: start by defining measurable goals (e.g., reduce reaction time by 15% while maintaining >95% accuracy), then outline a two-week plan with specific drills, rest intervals, and progress tracking. Emphasize how you'll use data to adjust the plan, showing a scientific, iterative mindset that aligns with Optiver's data-driven culture.

Pro tip: Mention that you'll track both speed and accuracy to avoid the speed-accuracy tradeoff, and use a simple tool like a spreadsheet or a custom script to log daily results—this demonstrates technical initiative and analytical rigor.

1. Set clear, measurable goals

Define specific targets for reaction time and accuracy, such as reducing average reaction time by 15% while keeping accuracy above 95% on the task-switching exercise.

2. Design daily drills with progressive overload

Plan daily 20-30 minute sessions using tools like online reaction time tests or custom scripts, gradually increasing difficulty (e.g., more task switches, shorter intervals) to challenge your cognitive flexibility.

3. Incorporate rest and recovery

Schedule short breaks (e.g., 5 minutes after every 10 minutes of drilling) and at least one full rest day per week to prevent mental fatigue and consolidate learning.

4. Track progress with metrics

Log daily reaction times and accuracy rates in a spreadsheet, and compute weekly averages to visualize trends and identify plateaus.

5. Review and adjust weekly

At the end of each week, analyze the data to see what worked, then tweak the plan (e.g., increase intensity, change drill type) for continuous improvement.

Key Points to Mention

  • Use of specific drills like alternating between two tasks (e.g., number and letter categorization) with timed responses.
  • Rest intervals based on principles of deliberate practice (e.g., 5-minute breaks after 10 minutes of focused work).
  • Measurement of both reaction time (milliseconds) and accuracy (percentage correct) to avoid tradeoffs.
  • Progress tracking via daily logs and weekly averages, with visualizations to spot trends.
  • Adjustment of difficulty based on performance to maintain optimal challenge (flow state).
  • Application of a scientific method: hypothesize, test, analyze, iterate.

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.