E4 Software Engineer Interview Prep
Mid-level prep for Meta's E4 loop - high coding bar, one system design round, and mid-level behavioral signal.
About this loop
Meta E4 is the mid-level rung (3-5 YOE) and the most common landing point for engineers transitioning into Meta from other big tech companies. The loop is shorter than E5: two coding rounds, one system design round, and one behavioral round. The coding bar is still notably high - Meta's signature is two problems per 45-minute round at Medium-to-Hard difficulty, with pace as the real test. System design appears at E4 (unlike E3) but with bounded scope - URL shortener, news feed (lite), basic chat, simple notification system. Drive the conversation; silence is a downlevel signal. Behavioral is mid-level expectations: shipping impact, collaboration, navigating ambiguity at a project scope. 'I shipped a feature' lands at E4 if it's specific and has metrics; the same answer at E5 would underperform.
The interview loop
- 1Recruiter screen30 minutes. Level calibration (E3 vs E4 vs E5), team interest, logistics.
- 2Phone screen (technical)45 minutes, two coding problems back-to-back. Pace matters - if you don't finish both, that's a signal.
- 3Onsite: Coding round 145 minutes, two algorithmic problems. Medium-to-Hard. Trees, graphs, hash maps, intervals are common.
- 4Onsite: Coding round 245 minutes, two more problems with a different interviewer. Different topics from round 1. Follow-ups probe depth.
- 5Onsite: System design45 minutes. Bounded scope at E4 - URL shortener, news feed (lite), chat (basic), notification system. Drive the conversation, defend tradeoffs.
- 6Onsite: Behavioral45 minutes. Mid-level expectations - shipping impact, collaboration, navigating ambiguity at project scope. Bring specific stories with metrics.
What Meta actually evaluates
- →Speed and code volume - clearing two problems per coding round signals E4-ready pace
- →Driving system design without prompting, even at bounded scope
- →Specific shipping stories with metrics tied to product impact
- →Edge cases handled in coding without being asked
- →Clear thinking about tradeoffs - 'I picked X over Y because Z' framing
- →Pragmatism on follow-ups - knowing when 'good enough' beats 'theoretically perfect'
Topics tested
Algorithms
Two coding rounds with two problems each. Pace ruthlessly - 12-15 minutes per problem leaves room for follow-ups. Trees, graphs, dynamic programming, intervals all appear regularly.
Data Structures
Trees, graphs, heaps, hash maps. Meta loves graph problems and tree DP. Know BFS/DFS variants cold.
System Design
One round at E4, bounded scope. Practice URL shortener, news feed (lite), chat, notification system. Drive the conversation - silence is a downlevel signal even at E4.
Behavioral
Mid-level signal. Stories about shipping impact, collaboration, navigating project-scope ambiguity. Specific incidents with metrics beat generic narratives.
Databases
Comes up in system design - sharding, indexing, basic consistency tradeoffs. Rare as a standalone round.
Object-Oriented Design
Sometimes used in coding rounds with a design-shaped problem. Clean class boundaries are enough.
System design topics tested in this loop
Curated walkthroughs for the bounded designs that show up in Meta'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.
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.
Rate Limiter
MediumFive algorithms, three sharding strategies, one fail-open vs fail-closed decision. The bounded design that surfaces in every backend interview loop.
Behavioral themes tested in this loop
Sample STAR answers, common prompts, pitfalls, and follow-up strategies for the behavioral themes that decide Meta's loop.
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.
Ambiguity
GeneralTested at Google, Anthropic, OpenAI, and any senior+ loop. Strong candidates show how they get curious; weak candidates show how they get anxious.
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 Meta BETA
Total comp ranges, base, equity, and bonus across the levels tested in this loop. Aggregated from public sources.
Meta 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.
Algorithms · 77 MCQs
Browse all in Algorithms →Data Structures · 44 MCQs
Browse all in Data Structures →System Design · 68 MCQs
Browse all in System Design →Behavioral · 63 MCQs
Browse all in Behavioral →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 difference between E3 and E4 at Meta?
E3 is entry-level new grad (0-2 YOE) - coding focus, no system design, lighter behavioral. E4 is mid-level (3-5 YOE) and adds a system design round, raises the coding bar to Medium-to-Hard with pace expected, and shifts behavioral to project-scope impact stories. Many engineers transitioning into Meta from other big tech companies land at E4.
How do I clear both problems in a 45-minute coding round?
Pace ruthlessly. Spend 2-3 minutes clarifying, code in 12-15 minutes, walk through with one example, move to the next problem. Take hints quickly if stuck - the interviewer will help. Practice with a timer and force yourself to move on. Most candidates over-explain and run out of time.
What system designs come up at E4?
URL shortener, news feed (lite version - read path with caching, less depth on write path), basic chat, notification systems, simple search. Bounded scope versus E5. The interviewer is evaluating whether you can drive a 45-minute conversation, identify reasonable scale, and defend basic tradeoffs (caching, sharding, consistency).
Is E4 equivalent to Google L4 or Amazon SDE II?
Roughly, yes. All three are mid-level rungs targeting 3-5 YOE. Compensation is broadly comparable. The interview difficulty differs: Meta's coding bar is the highest of the three (pace is brutal), Amazon's behavioral bar is the highest (every round probes Leadership Principles), Google sits between. Many engineers find Meta's two-problems-per-round format the most stressful, even if individual problems aren't harder.
How important are metrics in behavioral stories at E4?
Important but not as critical as at E5. At E4, 'I improved performance' is acceptable if you can describe what specifically you did and what happened. At E5, the same answer needs numbers (latency before/after, users affected, business impact). Use metrics where you have them - they always score higher.
How long is the E4 loop end-to-end?
Recruiter screen to offer typically 6-10 weeks. Onsite is usually compressed to one or two days. Hiring committee review is fast (1 week). Team matching adds 2-4 weeks. Plan for 8-12 weeks total.