Meta E4 Interview Guide
Mid SWE loop, same coding bar as E3 plus a system design round and behavioral that probes scope and ownership.
Process overview
The E4 loop runs 5–7 weeks. Same screening flow as E3 (recruiter screen, OA, technical phone screen) but the onsite expands to 5 rounds: 2 coding, 1 system design, 1 behavioral, 1 hiring-manager round (sometimes combined with behavioral).
How it differs from E3
- System design is added as a full round, this is the round that decides level between E3 and E4.
- Behavioral expectations grow, E3 tests collaboration; E4 tests independent ownership ("you led X end-to-end with little supervision").
- Coding bar is the same as E3, but the expectation is faster execution and cleaner code under time pressure.
Onsite (5 rounds)
Coding 1
Same format as E3 coding rounds. Bar is calibrated identically, what changes is the expected delivery speed and follow-up depth.
Coding 2
Often skews harder than Coding 1, with one medium and one hard. Common categories: DP, intervals, advanced graphs, design (e.g., LRU cache).
System Design
Open-ended product or infrastructure design. Examples: design Instagram feed, design a chat system, design a URL shortener, design a typeahead service.
Expected flow:
- Clarify requirements (3 min), functional + non-functional, scale numbers.
- Capacity estimation (3 min), QPS, storage, bandwidth.
- High-level design (10 min), boxes-and-arrows, data flow.
- Deep dives (20 min), interviewer picks 1–2 components to explore: storage schema, sharding, caching, consistency.
- Tradeoffs and bottlenecks (5 min), what breaks at 10x scale.
Evaluation criteria
- Requirements scoping
You drive the conversation toward concrete requirements rather than waiting to be told.
- Tradeoff articulation
When you pick a database, queue, or replication strategy, you explain what you traded away and why it's acceptable here.
Strong signal: You preempt the interviewer's "but what about X?" by raising the tradeoff yourself.
- Depth on a chosen component
You can go 3+ levels deep on one piece, schema, indexes, query patterns, failure modes.
Behavioral ('Jedi')
Same structure as E3 but with sharper probes on scope ("how big was the project, in headcount and timeline?") and influence ("who pushed back, and how did you bring them along?").
Stories should land at the multi-quarter, cross-team size for E4. Single-sprint contributions feel like E3.
Hiring Manager
Often merged into the behavioral slot. The HM is calibrating fit and seniority, they may probe one technical area informally.
Evaluation criteria
Evaluation criteria
- Coding
Same bar as E3, but expected faster.
- System design
Drives the conversation, articulates tradeoffs, goes deep on one component.
Strong signal: Suggests two viable architectures and chooses one with explicit reasoning.
- Ownership (behavioral)
Stories show end-to-end delivery of multi-month projects with cross-functional inputs.
- Influence (behavioral)
Examples of bringing peers or stakeholders along through disagreement.
Common questions
Most commonly asked questions
- CodingmediumLRU CacheLC 146
- CodingmediumWord Break IILC 140
- CodinghardSerialize and Deserialize Binary TreeLC 297
- CodinghardAlien DictionaryLC 269
- System DesignDesign Instagram's news feed.
- System DesignDesign a typeahead / search autocomplete service.
- System DesignDesign a chat application like Messenger.
- BehavioralDescribe a multi-month project you owned end-to-end.
- BehavioralTell me about a time you influenced a decision outside your team.
Preparation plan
| Week | Focus | Exit criteria |
|---|---|---|
| 1–2 | LC mediums (arrays, trees, graphs, DP) | 30 mediums solved in <25 min each |
| 3 | System design fundamentals (storage, caching, sharding, queues) | 5 written design walkthroughs |
| 4 | System design reps (Instagram, chat, typeahead, URL shortener, ride-sharing) | 5 mock designs at 45 min each |
| 5 | Behavioral STAR stories + 2 mocks | 4 stories scoped to E4 (multi-quarter, cross-team) |
| 6 | Final mocks + Meta-tagged LC | 3 final loops with no flagged round |