Senior SDE Interview Prep

About this loop

Microsoft Senior SDE (sometimes called SDE III, internal level 63-64) is the senior IC level - 5-8 YOE engineers expected to lead components, mentor SDE IIs, and influence technical decisions across the team. The loop expands meaningfully from SDE II: typically two design rounds (one product/applied, one infra/architecture), an as-app round with senior behavioral expectations, and 1-2 coding rounds at Medium-to-Hard difficulty. Cross-team scope shows up in behavioral signal - 'I shipped a feature' lands at SDE II but is below bar at Senior; you need stories about driving technical direction, mentoring SDE IIs, navigating cross-team disagreement, and recovering from architectural decisions. Growth Mindset framing remains, now applied at senior scope: how do you lead through ambiguity, how do you grow engineers, how do you change your mind based on broader feedback. Azure depth becomes more relevant at Senior level for cloud-adjacent teams - knowing distributed systems patterns from Azure (Service Fabric, Cosmos DB, Service Bus) gives you concrete vocabulary in design rounds.

The interview loop

1. 1
   Recruiter screen

   30-45 minutes. Background, level calibration (SDE II vs Senior is contested), team interest, scope of past work. Recruiter often probes cross-team impact stories early.
2. 2
   Phone screen (technical)

   60 minutes. One coding problem at Medium-to-Hard difficulty plus 2-3 behavioral questions with senior framing. Pass to advance to onsite.
3. 3
   Onsite: Coding round 1

   60 minutes. Algorithmic problem at Medium-to-Hard. Edge cases and clean code expected as table stakes; the differentiator is depth on follow-ups.
4. 4
   Onsite: Coding round 2 (sometimes)

   60 minutes. Some Senior loops include a second coding round; others replace it with a design or applied round. Often more open-ended (system design lite, OOD problem, or extending an existing system).
5. 5
   Onsite: System design 1 (product/applied)

   60 minutes. Senior-scope service design: notification system at scale, distributed key-value store, basic search, recommendation system. Drive the conversation, defend tradeoffs explicitly.
6. 6
   Onsite: System design 2 (infra/architecture)

   60 minutes. Lower-level design: distributed cache, rate limiter, log aggregation, message queue. Azure depth (Service Fabric, Cosmos DB, Service Bus) helps for cloud-adjacent teams.
7. 7
   Onsite: As-app (hiring manager)

   60-75 minutes. Senior IC behavioral signal. Stories about technical leadership, mentoring SDE IIs, navigating cross-team disagreement, recovering technical decisions. Growth Mindset at senior scope.

What Microsoft actually evaluates

• →Cross-team scope behavioral stories - 'I drove our team's technical direction' beats 'I shipped feature X'
• →Driving system design rounds proactively - silence is a downlevel signal at Senior level
• →Mentoring and growth signal - specific stories about engineers you've grown
• →Growth Mindset at senior scope - leading through ambiguity, changing your mind based on broader feedback
• →Hard-problem coding finished cleanly with deep follow-ups answered
• →Azure depth for cloud-adjacent teams - distributed systems patterns from Azure ecosystem

Topics tested

System design topics tested in this loop

Curated walkthroughs for the bounded designs that show up in Microsoft's system design rounds. Capacity estimation, architecture, deep-dives, and trade-offs.

Behavioral themes tested in this loop

Sample STAR answers, common prompts, pitfalls, and follow-up strategies for the behavioral themes that decide Microsoft's loop.

Compensation at Microsoft BETA

Total comp ranges, base, equity, and bonus across the levels tested in this loop. Aggregated from public sources.