Glean's Interview Process (2026)

Blog / Glean's Interview Process (2026)
Glean Interview Process
Glean's software engineer interview process is rigorous and typically runs 3 to 5 weeks from first contact to offer. Most candidates report a multi-stage pipeline that rewards clear thinking and strong fundamentals over speed alone.
  • Recruiter Screen: Usually a 15 to 30 minute call covering your background, interest in Glean, and logistics. Expect a conversation about fit rather than anything deeply technical.
  • Hiring Manager Screen: A video call, typically around 45 minutes, focused on your past projects and the reasoning behind your technical decisions. Be ready to explain the 'why' behind your choices, not just the 'what'.
  • Technical Phone Screen: Usually a 60-minute live coding session on a collaborative platform. Most candidates report one Medium-to-Hard level coding problem, followed by a brief discussion on trade-offs and complexity.
  • Virtual Onsite: The onsite generally includes 4 to 5 rounds covering coding, system design, a practical 2-hour assignment, and a behavioral round. Senior candidates often have an additional conversation with a founder or executive.
  • Coding Rounds: Typically two rounds focused on data structures, algorithms, and clean implementation. Glean is known to ask Hard-level problems in the final stages, so prepare accordingly.
  • System Design Round: A deep architectural discussion, often grounded in real-world constraints like multi-tenancy and permission-aware search. You are expected to go well beyond drawing boxes.
  • Practical Assignment Round: A standout feature of Glean's process: a 2-hour build-from-scratch coding session. Past candidates have been asked to implement a Table Module with join support or a Stream Processor, starting from an empty file.
  • Behavioral Round: A conversation around values, collaboration style, and how you handle ambiguity. Glean places real weight on culture fit, so treat this round seriously.
  • Executive or Founder Interview: Common for Senior and above roles. Expect a mission-focused conversation about why Glean and what you want to build.
To prepare effectively, focus your energy across these key areas that Glean consistently tests:
  • Data Structures & Algorithms (DSA): LeetCode-style coding problems, often at Medium-to-Hard difficulty, tested across the phone screen and onsite coding rounds.
  • Low-Level Design (LLD): The 2-hour practical assignment where you build a working module from scratch using clean, object-oriented principles.
  • System Design: Architecture and scalability discussions with a focus on real-world constraints like permission-aware search and multi-tenancy.
  • Behavioral: Values and collaboration questions evaluating your alignment with Glean's mission and engineering culture.
  • Math and First-Principles Thinking: An occasional non-coding round testing mathematical reasoning and the ability to prove concepts from first principles.
1. Data Structures & Algorithms (DSA)Glean's coding rounds are genuinely hard. While many companies stay at Medium difficulty, Glean frequently pushes into Hard territory in the onsite, so calibrate your prep accordingly. Start with our top 100 DSA questions to make sure your fundamentals are solid before tackling harder material.Recent candidates have reported questions like finding the kth largest element across multiple arrays, Shortest Distance from All Buildings, and Rotate Image. Graph problems come up often, so make sure you are comfortable with both BFS and DFS traversal patterns through our graphs collection.One problem that has come up in recent cycles is the Connect Four Challenge, which tests your ability to implement game logic cleanly under time pressure. Matrix problems like Max Area of Island also appear, so brush up on your matrix traversal techniques.Interviewers at Glean are known to care more about your reasoning than raw speed. Explain your choice of data structure before you start coding, walk through edge cases out loud, and discuss time and space complexity as you go.
2. Low-Level Design (LLD)The 2-hour practical assignment is widely considered the hardest and most differentiating round in Glean's process. You are given a blank file and asked to build a working, extensible module from scratch. Past examples include implementing a Table Module (adding rows, columns, then joins) and a Stream Processor.The key is writing clean, object-oriented code that can be extended without a full rewrite. Think in terms of interfaces, single responsibility, and separation of concerns from the very first line you write. Practice with Low-Level Design practice to get comfortable building small systems quickly.Problems like Connect 4 Backend and All O`one Data Structure are good proxies for the kind of thinking this round demands. Time yourself strictly during practice so the 2-hour constraint feels familiar on the day.
3. System DesignGlean's system design round is grounded in the realities of building enterprise search, so generic answers will not cut it. Interviewers expect you to reason about multi-tenancy, data isolation, and how to ensure users only see results they have permission to access. Brush up on High-Level Design concepts before the interview.Common topics include designing a commenting system with a clean API and DB schema, architecting a real-time indexing pipeline, and handling permission-aware search across third-party sources like Jira and Slack. For Senior candidates, topics can extend to rate-limiting third-party SaaS connectors and solving cold-start problems for new customers.Since Glean's core product is built around search, it helps to understand concepts like inverted indexes and ranking at a working level. Use our System Design AI Whiteboard to practice drawing and talking through architectures end to end.
4. BehavioralGlean takes the behavioral round seriously, and candidates who treat it as a warm-up tend to get caught off guard. Expect questions about how you collaborate under pressure, how you handle disagreement, and why Glean specifically. Have two or three strong project stories ready that you know deeply.Structure your answers clearly using the STAR format to keep your responses focused and easy to follow. The Behavioral Interview Course is a good place to practice before the real thing.
5. Math and First-Principles ThinkingSome candidates, particularly those interviewing for New Grad or Junior roles, report a non-coding math proof round. One example that has come up is proving why the median minimizes the sum of absolute differences in an array. This round is not about memorizing proofs but about thinking clearly from first principles.To prepare, practice explaining mathematical reasoning out loud as if teaching someone. If you can derive the answer step by step and articulate why each step follows from the last, you will handle this round well.
ConclusionGlean has one of the more demanding interview pipelines at the startup level, but it is also very structured once you know what to expect. Focus your prep on Hard DSA, the LLD assignment, and search-specific system design to cover the rounds that trip most candidates up. Follow the Glean Interview Roadmap for a step-by-step plan to work through each stage efficiently.

About TechPrep

Never walk into a technical interview unprepared again. TechPrep empowers software engineers to stop guessing and start getting offers. We provide the exact questions asked by tech companies across Data Structures & Algorithms, System Design, Low-Level Design & Practical coding rounds. Don't leave your career up to chance. Join thousands of engineers who have successfully navigated the tech hiring maze and landed roles at top tech companies.