ttl Interview Questions
12 interview questions in our bank cover ttl, most of them Coding & Leetcode-style Questions. They average 3.4/5 difficulty — medium — and each one was reported by a candidate after a real interview. Companies known to ask about ttl: Netflix, xAI, Tesla, The Trade Desk, Meta, and 6 more.
Practice these on the problems board →Companies that ask about ttl
Question mix
- Coding & Leetcode-style Questions11
- System Design for ML1
Difficulty
- 3/5 — medium7
- 4/5 — hard5
Questions tagged ttl
Thread-Safe KV Store, Atomic Counter, Blocking Queue
4/5This practical concurrency puzzle, reported during software engineering interviews at Netflix, requires building robust synchronization primitives in Python, specifically an atomic counter supporting compare-and-swap semantics and a bounded blocking queue. It tests your mastery of multi-threading mechanics, thread safety, locks, and condition variables under high-contention scenarios. To view the full problem description and production-ready code solution, unlock your subscription today.
Coding & Leetcode-style QuestionsNetflixIn-Memory Database — Levels 1–4 (TTL + Backup/Restore)
3/5Reported as an xAI multi-level online assessment for infrastructure engineers, this challenge requires building an incremental in-memory key-value database from scratch. You will progressively implement field operations, range scans, time-to-live expiration policies, and snapshot backup functionality. It thoroughly tests systems design intuition and modular code organization under strict constraints. Access the complete tiered requirements and robust reference implementation with a paid subscription.
Coding & Leetcode-style QuestionsxAIPriority + Expiration + LRU Eviction
3/5This advanced cache eviction problem, featured in a Tesla coding assessment, asks candidates to implement a custom removal policy based on multiple criteria. The module must prioritize clearing expired entries first, followed by evaluating item priority levels, and finally falling back to a least-recently-used strategy for tie-breaking. Mastering this question requires robust state management and efficient data structure design under strict constraints. Gain access to the complete problem description and expert solution with a subscription.
Coding & Leetcode-style QuestionsTeslaImplement an Internal Database
4/5Designed around a reported The Trade Desk interview task, this problem asks you to build a time-versioned key-value data store supporting conditional modifications, point-in-time retrievals, and range scanning. It assesses your proficiency in data structure design, concurrency-safe atomic operations, and handling temporal data states efficiently. You will need to implement robust storage mechanisms to manage history across timestamps. Access the comprehensive problem description and complete verified solution by subscribing.
Coding & Leetcode-style QuestionsThe Trade DeskDesign a Ticketing System with Flash-Sale Concurrency
4/5Framed around a high-traffic Meta system design interview, this prompt asks you to architect a robust ticket reservation platform capable of handling massive concurrency during sudden flash sales. Key areas of discussion include managing temporary inventory holds, ensuring strict consistency during checkout spikes, and designing reliable seat-map browsing features. You will need to balance scalability, latency, and race-condition mitigation under heavy load. Full access to the comprehensive architectural guide and model solution requires a subscription.
System Design for MLMetaLRU Cache with TTL or Weighted Size
3/5This Snapchat interview exercise expands upon traditional cache design by incorporating production-grade requirements like time-to-live expirations and capacity limits based on item weight. You must carefully balance retrieval speed with eviction policies to maintain optimal memory constraints under heavy loads. The challenge tests your grasp of advanced data structures, pointer manipulation, and time-aware algorithms. To read the entire problem guide and study the comprehensive model solution, a subscription is required.
Coding & Leetcode-style QuestionsSnapchatIn-Memory Database - Cloud Storage (Multi-Level OA)
3/5Build a robust multi-level in-memory database storage system in this engaging Coinbase online assessment challenge. This problem tests your ability to design nested data structures that support timestamped operations, conditional updates, and transactional data retrieval efficiently. You will evaluate how to manage state across hierarchical collections while handling strict ordering constraints and missing keys gracefully. Unlock the complete evaluation guidelines and comprehensive reference code by purchasing a subscription.
Coding & Leetcode-style QuestionsCoinbaseWeighted Cache / Timed (TTL) Cache
3/5This Netflix interview question explores the design of custom caching mechanisms featuring either weighted capacity eviction or per-item time-to-live expirations. It tests your knowledge of concurrency control, efficient memory management, and data structure trade-offs for high-throughput systems. The full problem breakdown, implementation guidelines, and a production-grade model solution require a subscription.
Coding & Leetcode-style QuestionsNetflixDesign and Implement an In-Memory Key-Field-Value Storage System (KV Database)
4/5Building a robust in-memory data store from scratch is a rigorous test of system design and programming fundamentals, as explored in this ZipRecruiter interview scenario. You will implement a hierarchical key-field-value storage architecture that evolves from basic retrieval and conditional mutations to advanced scanning capabilities. The task emphasizes clean interface design, concurrency safety considerations, and efficient data organization in memory. To review the full problem specifications and a production-grade model solution, a subscription is required.
Coding & Leetcode-style QuestionsZipRecruiterImplement LRU Cache with TTL and Rate Limiter
4/5This advanced system design and coding challenge from Commure asks candidates to build a customized least recently used cache featuring individual expiration timers and basic rate limiting. The problem tests your mastery of composite data structures, efficient hash map and doubly linked list integrations, and time-based eviction policies. You will need to carefully manage state transitions, handle resource expiration, and enforce throughput restrictions within strict performance bounds. The full problem and model solution require a subscription.
Coding & Leetcode-style QuestionsCommureLRU Cache with Expiration (LC 146 + TTL)
3/5This Oracle interview question delves into advanced data structure design, combining the principles of a Least Recently Used (LRU) cache with an additional layer of complexity: time-to-live (TTL) expiration. You'll need to engineer a cache that supports efficient O(1) operations for both retrieval and insertion, while also ensuring that entries automatically become invalid after a specified duration. This problem tests your understanding of hash maps, linked lists, and how to integrate temporal logic into a performant caching mechanism. The full problem and model solution require a subscription.
Coding & Leetcode-style QuestionsOracleTTL Cache with Fetch on Miss
3/5Reported during a Tubi technical interview, this systems-design coding task challenges you to build a robust in-memory time-to-live cache featuring automatic data expiration and asynchronous fetch-on-miss capabilities. The exercise tests your knowledge of thread safety, efficient data structures, and precise expiration tracking over millisecond intervals. Success requires designing clean APIs that handle concurrent data access and retrieval failures gracefully. Get full access to the comprehensive problem requirements and optimal implementation code with a subscription.
Coding & Leetcode-style QuestionsTubi
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ttl interview FAQ
- How many ttl interview questions are there?
- 12 reported questions, mostly Coding & Leetcode-style Questions.
- Which companies ask ttl questions?
- Netflix (2), xAI (1), Tesla (1), The Trade Desk (1), Meta (1), Snapchat (1), Coinbase (1), ZipRecruiter (1).
- How hard are ttl questions?
- They average 3.4 out of 5: 7 at 3/5, 5 at 4/5.