Low-level designLast seen Sep 2026
Design an Elevator Control System
Model elevator cars, hall and cabin requests, dispatch assignment, movement state, and safe fault handling.
Open practiceThe Trade Desk interview practice
The Trade Desk Coding Interview and Stateful Practice Start with verified evidence.
Practice from 9 The Trade Desk-tagged public coding problems, organized only by the stage, topic, difficulty, and recency metadata FastPrep can verify. The broader public catalog also includes 2 low-level-design exercises.
- Catalog
- 11 public practice assets (9 coding)
- Start here
- Use the stage named in your invitation
- Evidence
- OA metadata, shown in context
OA practice path
Online Assessment
Build a timed implementation rhythm from prompt to edge cases. Problems are ranked by repeated public catalog sightings.
9 The Trade Desk-tagged Online Assessment problems available.
| Company | Problem | Difficulty | Public evidence | Action |
|---|---|---|---|---|
TTThe Trade Desk | Versioned Recipe SystemDesignHash Table | Hard | 2 public reportsLast reported Jul 2026 | Practice |
TTThe Trade Desk | Temporal Key-Field Database with Prefix ScansDesignHash Table | Medium | 1 public reportLast reported Aug 2026 | Practice |
TTThe Trade Desk | Light Sources 🩵IntervalsSorting | Medium | 1 public reportLast reported Jul 2024 | Practice |
TTThe Trade Desk | Tally the Number of Friend Groups with K Sets of Matching Traits 🐰ArraySliding Window | Medium | 1 public reportLast reported Mar 2024 | Practice |
TTThe Trade Desk | Buddies Greater than Target 🦋ArraySliding Window | Easy | 1 public reportLast reported Mar 2024 | Practice |
TTThe Trade Desk | Flights 🚁SimulationSorting | Easy | 1 public reportLast reported Mar 2024 | Practice |
TTThe Trade Desk | Earn the Most 🐝ArraySliding Window | Medium | 1 public reportLast reported Mar 2024 | Practice |
TTThe Trade Desk | Last to Be Checked 🐳ArraySimulation | Medium | 1 public reportLast reported Mar 2024 | Practice |
TTThe Trade Desk | Narrative Words 🐥String | Easy | 1 public reportLast reported Mar 2024 | Practice |
01 · Preparation plan
Treat time and versions as part of the data contract.
The Trade Desk's public catalog includes stateful exercises that reward careful treatment of history. Temporal fields and recipe versions make stronger preparation anchors than a generic algorithm list. The interval exercise adds a compact correctness check; none of these tasks documents the company's advertising infrastructure. This is a suggested practice sequence, not the employer's interview process. Your invitation and recruiter guidance remain the source of truth.
- 01
Keep scans consistent with temporal visibility
The key-field database exercise connects reads, expiration, and prefix scans. A scan must follow the same visibility rules as a single-field lookup.
- Define time and expiry boundaries.
- Test a prefix with no visible fields.
- Use deterministic scan ordering.
- 02
Preserve historical versions
Use the recipe system to distinguish editing the latest state from rewriting history. Decide which operations create a new version and how old versions are queried.
- Trace multiple edits to one recipe.
- Test an unknown version.
- Avoid aliasing mutable data across versions.
- 03
Represent overlapping illumination
Light Sources is useful for practicing interval coverage. The important preparation step is a clear endpoint convention before sorting or sweeping events.
- Test touching and nested ranges.
- Order equal-position events deliberately.
- Compare with a direct small-coordinate simulation.
02 · Broader technical practice
Practice beyond standalone coding questions.
These public The Trade Desk-tagged exercises cover additional technical formats. They are included only when a verified catalog record and a crawlable practice page both exist.
Low-level designLast seen Sep 2026
Design an In-Memory Publish-Subscribe Library
Model one application-scoped event manager, token-based subscriptions, snapshot delivery, and truthful per-callback outcomes.
Open practice03 · Evidence boundary
What “The Trade Desk interview questions” means here.
It means practicing transferable implementation, testing, and technical reasoning with public catalog assets FastPrep tags to The Trade Desk. It does not mean FastPrep has access to the company's assessments or any private interview bank.
Repeated public sightings and last-reported dates can help you prioritize practice, but they cannot predict the questions, format, or platform in a specific interview.
- Only The Trade Desk-tagged FastPrep catalog problems appear above.
- Stage labels and report dates remain visible as context.
- No official, private, leaked, or proprietary questions are claimed.
04 · Plain answers
The Trade Desk interview practice questions, answered plainly.
This page owns technical-practice intent for The Trade Desk. Hiring activity, timelines, and market signals remain on the separate hiring-insights page.
01Does this teach The Trade Desk's ad-bidding architecture?
No. The available evidence supports coding practice, including temporal and versioned state. Advertising-domain assumptions should not be inferred from the company name. Use the exercises to practice contracts and data structures, then consult role-specific guidance for any additional system or industry knowledge.
02Is FastPrep affiliated with The Trade Desk?
No. FastPrep is an independent interview-preparation product and is not affiliated with The Trade Desk. The page uses FastPrep's public practice catalog and does not claim official, private, leaked, or proprietary employer questions.
03How are The Trade Desk problems assigned to interview stages?
Stage labels come from FastPrep's public problem metadata. A problem can carry more than one reported stage, and hiring processes can change by role, level, location, and date. Treat the labels as preparation context, not a guarantee.
04Which The Trade Desk interview stage should I practice first?
Start with the stage named in your invitation or recruiter message. If no stage is known, use the largest available set to build general problem-solving fluency, then rehearse explanation and testing separately.
05Does this page predict the The Trade Desk interview process?
No. Public catalog counts, stage tags, and last-reported dates can help prioritize practice, but they cannot predict a specific interview's questions, sequence, timing, or platform.
Your next stage, made concrete
Pick a problem. Solve it end to end.
Start with the stage named in your invitation, then use public evidence as context—not as a promise of what you will be asked.
Open the practice set