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Mid-level prep for Meta's E4 loop - high coding bar, one system design round, and mid-level behavioral signal.
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.
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.
Trees, graphs, heaps, hash maps. Meta loves graph problems and tree DP. Know BFS/DFS variants cold.
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.
Mid-level signal. Stories about shipping impact, collaboration, navigating project-scope ambiguity. Specific incidents with metrics beat generic narratives.
Comes up in system design - sharding, indexing, basic consistency tradeoffs. Rare as a standalone round.
Sometimes used in coding rounds with a design-shaped problem. Clean class boundaries are enough.
Curated walkthroughs for the bounded designs that show up in Meta's system design rounds. Capacity estimation, architecture, deep-dives, and trade-offs.
The canonical bounded system design problem. Read-heavy, hot-key prone, and a great vehicle for hashing, caching, and capacity estimation.
The classic write-vs-read amplification trade-off. Push, pull, or hybrid fanout - and how to handle the celebrity user with 100M followers.
Long-lived connections, ordering guarantees, presence, and the difference between 1:1 chat and a 50K-member group.
Five algorithms, three sharding strategies, one fail-open vs fail-closed decision. The bounded design that surfaces in every backend interview loop.
Sample STAR answers, common prompts, pitfalls, and follow-up strategies for the behavioral themes that decide Meta's loop.
Tested at every level, scored harder at senior. Did you take responsibility for outcomes - or just for tasks?
Speed matters. But the principle is reversible-vs-irreversible reasoning, not 'I work fast.' Get this distinction wrong and the answer reads as reckless.
Tested at Google, Anthropic, OpenAI, and any senior+ loop. Strong candidates show how they get curious; weak candidates show how they get anxious.
Microsoft's Growth Mindset core. Also tested at Google, Anthropic, and any company that screens for self-awareness. The signal is whether you actually changed.
Total comp ranges, base, equity, and bonus across the levels tested in this loop. Aggregated from public sources.
5 SWE levels covered. Updated 2026-05.
357 MCQs and 237 coding challenges, grouped by topic. Free preview shows question titles - premium unlocks full content.
Behavioral and system design rounds reward practice with a live AI interviewer that probes follow-ups, not silent reading.
Start an AI mock interview →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.
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.
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).
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.
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.
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.