Senior SDE (L6 / SDE III) Interview Prep
Senior-level prep for Amazon's L6 loop - deeper system design, tougher Bar Raiser, and Leadership Principles probed at multi-team scope.
About this loop
Amazon Senior SDE (L6, also called SDE III) is the senior IC level - 7-10 YOE engineers expected to lead components, mentor SDE IIs, and influence technical decisions at multi-team scope. The loop structure is similar to SDE II but the bar shifts dramatically: coding rounds expect Hard problems with edge cases handled cleanly, system design rounds go deep on tradeoffs and failure modes, and the Bar Raiser probes Leadership Principles at scope levels SDE II candidates don't reach. Expect explicit testing of 'Have Backbone, Disagree and Commit,' 'Are Right A Lot,' 'Earn Trust,' and 'Hire and Develop the Best' - principles that show up lightly at SDE II but dominate at L6. Behavioral stories at SDE II ('I shipped this feature') are below bar at L6; you need stories about steering technical direction, mentoring senior engineers, recovering from architectural decisions, and influencing without formal authority. Like Google L6, Amazon promotes more SDE IIs to Senior SDE internally than it hires externally - external L6 candidates face a sharper calibration bar.
The interview loop
- 1Recruiter screen30-45 minutes. Background, level calibration (SDE II vs Senior SDE is contested), team interest. Recruiter often probes scope of past work as an early signal.
- 2Online assessment (sometimes)Skipped for many senior candidates. When present, two coding problems and a work simulation, similar to SDE II.
- 3Phone screen60 minutes. One coding problem (Medium-to-Hard) plus 2-3 deep Leadership Principle questions. The behavioral signal is heavier than at SDE II phone screens.
- 4Onsite: Coding round60 minutes. Hard problem or Medium with deep follow-ups. Edge cases and clean code expected as table stakes; the differentiator is depth on follow-ups.
- 5Onsite: System design60 minutes. Senior-scope designs: distributed key-value store, payment processing pipeline, real-time fraud detection, large-scale inventory tracking. Depth on tradeoffs, failure modes, and operational considerations expected.
- 6Onsite: Bar Raiser60 minutes. Cross-team senior engineer with veto power. Probes Leadership Principles at multi-team scope - 'Have Backbone,' 'Are Right A Lot,' 'Earn Trust,' 'Hire and Develop the Best.' SDE II behavioral stories often fail this round at L6 calibration.
- 7Onsite: Hiring manager / behavioral60 minutes. Senior IC role fit, technical leadership, mentoring signal. Manager calibrates whether you'd own a component end-to-end and grow SDE IIs to senior.
What Amazon actually evaluates
- →Multi-team scope behavioral stories - 'I steered our org's technical direction on X' beats 'I shipped feature Y'
- →Specific incidents of disagreement and outcome - 'Have Backbone' is heavily probed at L6
- →Mentoring and senior-IC growth - 'Hire and Develop the Best' becomes core, not occasional
- →Architecture-review depth on system design - tradeoffs, failure modes, operational considerations
- →Hard-problem coding finished cleanly with deep follow-ups answered
- →Calibrated technical judgment - knowing when to over-engineer vs ship simple
Topics tested
System Design
Senior-scope designs at L6. Practice distributed storage, payment pipelines, fraud detection at scale, large-scale inventory. Depth on tradeoffs, failure modes, and operational considerations expected - not just high-level architecture.
Behavioral
Leadership Principles probed at multi-team scope. Prepare stories specifically for 'Have Backbone, Disagree and Commit,' 'Are Right A Lot,' 'Earn Trust,' 'Hire and Develop the Best' - principles that surface lightly at SDE II but dominate at L6.
Algorithms
Hard or Medium-with-deep-follow-up. Edge cases and clean code are table stakes; the differentiator is depth on follow-ups. Pace ruthlessly to leave time.
Data Structures
Trees, graphs, heaps, advanced structures. The right structure should be quick - L6 candidates don't fumble structure choice.
Databases
Comes up in design at depth. DynamoDB-style thinking, hot partition mitigation, multi-region replication, transactional patterns. Senior SDEs at Amazon are expected to know AWS-style storage tradeoffs deeply.
Object-Oriented Design
Sometimes used in coding rounds with a service-design problem. Clean class boundaries and reasonable abstractions expected at L6.
System design topics tested in this loop
Curated walkthroughs for the bounded designs that show up in Amazon's system design rounds. Capacity estimation, architecture, deep-dives, and trade-offs.
URL Shortener
MediumThe canonical bounded system design problem. Read-heavy, hot-key prone, and a great vehicle for hashing, caching, and capacity estimation.
Distributed Cache
HardConsistent hashing, eviction, replication, and what really happens when a single hot key takes down the cluster.
Rate Limiter
MediumFive algorithms, three sharding strategies, one fail-open vs fail-closed decision. The bounded design that surfaces in every backend interview loop.
Web Crawler
HardPoliteness, deduplication, freshness, and the URL frontier. The classic crawl-the-internet question that surfaces deep distributed systems judgment.
News Feed
HardThe classic write-vs-read amplification trade-off. Push, pull, or hybrid fanout - and how to handle the celebrity user with 100M followers.
Chat
HardLong-lived connections, ordering guarantees, presence, and the difference between 1:1 chat and a 50K-member group.
Video Streaming
HardEncoding ladders, adaptive bitrate, CDN economics, and the difference between live and VOD. Petabyte-scale storage meets millisecond-scale playback.
Behavioral themes tested in this loop
Sample STAR answers, common prompts, pitfalls, and follow-up strategies for the behavioral themes that decide Amazon's loop.
Customer Obsession
Amazon LPThe most-asked Amazon LP. Interviewers screen for evidence you reasoned about end-user impact, not just shipped a feature.
Ownership
Amazon LPTested at every level, scored harder at senior. Did you take responsibility for outcomes - or just for tasks?
Bias for Action
Amazon LPSpeed matters. But the principle is reversible-vs-irreversible reasoning, not 'I work fast.' Get this distinction wrong and the answer reads as reckless.
Dive Deep
Amazon LPLeaders operate at all levels. The interviewer is testing whether you actually understand your own systems - or whether you summarize what your team built.
Conflict
GeneralThe most universal behavioral question. Tested everywhere. The signal is in how you investigate the disagreement, not in how you 'won.'
Learning from Failure
MicrosoftMicrosoft's Growth Mindset core. Also tested at Google, Anthropic, and any company that screens for self-awareness. The signal is whether you actually changed.
Compensation at Amazon BETA
Total comp ranges, base, equity, and bonus across the levels tested in this loop. Aggregated from public sources.
Amazon compensation by level
5 SWE levels covered. Updated 2026-04-29.
Curated practice questions
333 MCQs and 100 coding challenges, grouped by topic. Free preview shows question titles - premium unlocks full content.
System Design · 68 MCQs
Browse all in System Design →Behavioral · 63 MCQs
Browse all in Behavioral →Algorithms · 77 MCQs
Browse all in Algorithms →Data Structures · 44 MCQs
Browse all in Data Structures →Databases · 49 MCQs
Browse all in Databases →Object-Oriented Design · 32 MCQs
Browse all in Object-Oriented Design →Algorithms - Coding challenges · 71 challenges
Browse all coding challenges →Data Structures - Coding challenges · 29 challenges
Browse all coding challenges →Practice in mock interview format
Behavioral and system design rounds reward practice with a live AI interviewer that probes follow-ups, not silent reading.
Start an AI mock interview →Frequently asked questions
What's the real difference between SDE II and Senior SDE at Amazon?
SDE II owns features and projects, mentors SDE Is, and operates at single-team scope. Senior SDE (L6) owns components end-to-end, mentors SDE IIs, drives technical direction across multiple teams, and operates at multi-team scope. The interview bar shifts dramatically: behavioral stories that pass SDE II ('I shipped this feature') often fail at L6 calibration. The Bar Raiser at L6 probes 'Have Backbone,' 'Are Right A Lot,' 'Earn Trust,' and 'Hire and Develop the Best' specifically - principles that come up lightly at SDE II.
How is the Bar Raiser different at L6?
Tougher and broader. The Bar Raiser at SDE II probes Customer Obsession, Ownership, Bias for Action, and Dive Deep heavily. At L6, the same Bar Raiser shifts emphasis to senior-scope principles: Have Backbone (do you push back on technical decisions), Are Right A Lot (do you make calibrated judgments), Earn Trust (do peers and leaders trust you), Hire and Develop the Best (have you grown engineers). Without specific incidents at multi-team scope, candidates fail this round.
How do I prepare 'Have Backbone' stories?
Specific incidents where you disagreed with a senior engineer or leader, made your case clearly with data and reasoning, and stuck to your position even when it was uncomfortable. Either you persuaded them and the outcome was better, or you committed to their decision after a clear disagreement and made it work. Generic 'I push back when needed' answers fail. Concrete 'I disagreed with the principal engineer's approach because [data]; we ran a small experiment, the data supported my position, and we changed course' lands well.
How is L6 hiring different from L5?
Calibration scope shifts. L5 evaluates whether you can operate as a senior IC on a team. L6 evaluates whether you can operate at multi-team scope - mentoring senior engineers, driving technical direction, owning components end-to-end. Hiring committee specifically looks for 'has this person already operated at L6 scope.' External candidates often get downleveled to L5 because their stories are single-team.
Is L6 mostly internal promo?
Yes, more than at lower levels. Amazon promotes engineers it has calibrated. External L6 hires happen but face an additional calibration challenge: how do you confirm multi-team scope and senior-IC behavior without internal data? Reference checks matter significantly at L6. External Senior SDE candidates with strong references and specific multi-team scope stories have the best path.
What is comp like at L6?
Significantly higher than L5. Total compensation at L6 typically exceeds $400-500K depending on location and offer specifics, with a strong RSU component. Stock vest schedule is the standard Amazon back-loaded curve (5%/15%/40%/40%) which makes year 3-4 much higher than year 1-2. Negotiation is real and significant at L6.