Fast interviews are on par with top-tier FAANG in coding difficulty, typically featuring medium to hard LeetCode-style problems. The distinguishing factor is the heavy emphasis on Leadership Principles throughout all rounds, including the unique Bar Raiser round, which assesses cultural and behavioral alignment as rigorously as technical skill.
Aim for 2-3 months of structured prep: solve 150-200 LeetCode problems (70% medium, 30% hard), deeply study all 16 Leadership Principles with STAR-method stories, and for SDE-2+, practice system design fundamentals. Dedicate 1.5-2 hours daily with one full-length mock interview weekly to build stamina and communication.
For SDE-1, focus 70% on DSA and 30% on Behavioral (Leadership Principles). For SDE-2+, split your time: 40% DSA, 40% System Design (scalability, APIs, data storage), and 20% Behavioral. SDE-3 roles will have a heavier systems design and architectural trade-off focus, but Leadership Principles remain critical in every round.
Top mistakes include: 1) Neglecting to explicitly link solutions to Leadership Principles, 2) Not asking enough clarifying questions before jumping into code, 3) Failing to discuss time/space complexity or edge cases, and 4) Giving vague behavioral stories without clear outcomes. Always articulate your thought process aloud and tie your actions back to 'Customer Obsession' or 'Invent and Simplify'.
Stand-out candidates demonstrate exceptional problem decomposition (using examples), write clean, modular code with test cases, and deliver compelling, concise Leadership Principle stories with quantifiable results. They also proactively ask insightful questions about the team's challenges and show genuine curiosity about Fast's business model during the Bar Raiser and hiring manager rounds.
The process usually takes 4-8 weeks: 1-2 weeks for resume screening, 1-2 weeks for technical screens, and 2-4 weeks for the full loop (4-5 interviews). If you haven't heard back within 5 business days after your last round, a polite email to your recruiter is appropriate. Response times can vary by team urgency and hiring committee availability.
SDE-1: Heavy on core DSA and clean implementation, with basic behavioral alignment. SDE-2: Expects solid DSA, plus system design questions on single services, and deeper behavioral examples showing mentorship. SDE-3: Focuses on large-scale system design, trade-off analysis, technical strategy, and Leadership Principle stories that demonstrate driving cross-team initiatives and influencing product direction.
Essential resources: 1) Fast's official Leadership Principles page—memorize and practice stories for each, 2) LeetCode (filter for company-specific questions), 3) 'Grokking the System Design Interview' for SDE-2+, and 4) Mock interviews with current/former Fast engineers on platforms like Interviewing.io to simulate the Bar Raiser's behavioral deep-dive and coding communication style.
