Aon interviews are moderately difficult, focusing on medium-to-hard LeetCode-style problems and behavioral questions aligned with their leadership principles. Allocate 2-3 months for preparation: solve 150-200 coding problems, master core data structures, and practice behavioral stories using the STAR method. Emphasize understanding Aon's business domain in insurance and risk management to demonstrate contextual problem-solving.

Prioritize data structures (arrays, trees, graphs), algorithms (DFS, BFS, dynamic programming), and object-oriented design. For senior roles, study system design fundamentals with attention to scalability and distributed systems. Aon commonly uses Java or Python and AWS services, so ensure familiarity with these technologies and be ready to write clean, production-quality code.

Avoid jumping into coding without clarifying requirements and edge cases; communicate your thought process aloud. In behavioral rounds, don’t give vague answers—use specific examples that demonstrate Aon’s leadership principles like 'Customer Obsession' or 'Learn and Be Curious.' Also, failing to ask insightful questions about Aon’s projects or tech stack can signal lack of interest.

Stand out by linking your technical solutions to real business impact, such as how a system design improves client outcomes in insurance. Show enthusiasm for Aon’s mission and ask detailed questions about their engineering challenges. Demonstrate strong collaboration skills by discussing team experiences, as Aon values a client-focused, team-oriented culture.

Usually, you’ll hear within 1-3 weeks after the final round, but delays up to a month are common due to hiring cycles. If you haven’t heard after 10 business days, send a polite follow-up email to your recruiter. Note that Aon’s process may include a Bar Raiser round, which can extend the timeline.

SDE-1 focuses on implementing features and learning the codebase; expect coding challenges with clear specifications. SDE-2 requires more ownership, design input, and mentoring—prepare for system design questions. SDE-3 emphasizes architectural vision, cross-team leadership, and strategic impact; interviewers will assess your ability to drive large-scale solutions and influence technical direction.

Use LeetCode for coding practice (target 150-200 problems, emphasizing mediums), and Grokking the System Design Interview for senior roles. Review Aon’s engineering blog and careers page for tech stack insights. Practice behavioral questions with Amazon’s Leadership Principles, as Aon’s process often mirrors this, focusing on stories that demonstrate customer-centricity and innovation.

Aon fosters a collaborative, agile environment where engineers are expected to deliver client-focused solutions while continuously learning. They value strong communication, adaptability, and a growth mindset. Expect to work on projects that blend insurance domain expertise with modern tech, so business acumen and technical excellence are equally important.