Applicants for software roles at Twilio may receive a HackerRank screen before the live interview loop. One recent account described two to three medium problems in 60 to 90 minutes; another described a longer role-specific assessment. Use the invitation to confirm your exact duration and question count.

When to Expect the OA for Your Role

The online assessment occurs after application review but before problem-solving and design interviews. One software engineering candidate described two to three medium HackerRank problems in 60 to 90 minutes. Another early-career process used one coding problem in a longer session. Candidates for senior roles may skip the asynchronous test and begin with a recruiter or live technical screen.

Does Your Online Assessment Matter?

The coding screen helps determine who advances. Twilio does not share a company-wide cutoff. Correctness, complexity, and readable state handling all matter. Complete one problem before leaving unfinished code elsewhere in the set. A partial solution can still show progress.

Compiled List of Twilio OA Question Types

Recurring patterns include caches, trees, graphs, prefix sums, strings, windows, and stateful APIs.

1. LRU Cache - hash map with recency.
2. Binary Tree Maximum Path Sum - recursion for local and global states.
3. Course Schedule - detecting cycles in a dependency graph.
4. Continuous Subarray Sum - prefix remainders and earliest indices.
5. Group Anagrams - canonical string grouping.
6. Maximum Frequency Stack — frequency and recency invariants.
7. Sliding Window Maximum - maintaining a monotonic deque.
8. Design Hit Counter - time-window state in an API.

Twilio Interview Questions

Recently asked in real interviews

These questions were asked recently in real Twilio interviews. Practice these and 4,000+ other questions from 1,000+ companies on Lodely.

Implement LRU Cache.

algorithmscoding Hard

Given the root of a binary tree of integers, return the maximum path sum.

algorithmscoding Medium

Course Schedule

algorithmscoding Medium

Given an integer array nums and an integer k, return true if nums has a subarray of at least two elements whose sum is a multiple of k.

algorithmscoding Hard

What are you most proud of in your career?

behavioral Medium

Explore All Questions

Free to get started

How to Prepare and Pass the Twilio Online Assessment

If possible, prepare for two weeks. Week 1: Focus on maps, deques, trees, graphs, and prefix sums. Week 2: Complete three timed mocks and one review session for failed cases. For API-style problems, describe invalid inputs for each API and how the system should change state before coding. For graph problems, test a single-node graph and a two-node cycle. Use Lodely to add Twilio-specific system design and behavioral questions to your schedule.

Twilio Interview Question Breakdown

LRU Cache

Type: Data-structure design. Problem: Design a data structure that stores a fixed number of key-value pairs. When the size limit is reached, evict the least recently used entry. The Trick: Keep each element's recency synchronized with lookup operations. What It Tests: Designing invariants and constant-time operations.

Course Schedule

Type: Directed graph. Prompt: Can all dependencies be completed? The Trick: Detect cycles reliably using indegrees or state. What It Tests: Graph modeling and edge-case discipline.

What Comes After the Online Assessment

Successful candidates almost always move on to live problem solving, system design, and hiring manager or behavioral rounds. Twilio interviews can cover coding, APIs, and communications systems, so practice explaining reliability, rate limits, retries, and failure modes at a high level. Practice describing a design: state your assumptions before drawing its components. Keep behavioral examples specific to your own decisions.

Conclusion

Fully test and understand each problem before moving on. When you review failed cases, your reasoning will still be fresh. After your OA drills, use Lodely to prepare for Twilio coding, design, and behavioral interviews.