Meta Coding Interview: Format, Questions, and 2026 Prep

Meta's coding interview is two medium-difficulty algorithm problems solved out loud in about 35 minutes, run in CoderPad, judged as much on how you communicate as on whether you reach the optimal solution. The big change for 2026: Meta rolled out an AI-enabled coding round that replaces one of the traditional coding interviews at the onsite. If you have interviewed at Meta before, the fundamentals are the same, but the loop and the tooling have shifted. This guide breaks down the current process by level, what each round tests, and the exact problems that come up most, drawn from our own Meta question bank.

The Meta loop in 2026, by level

Meta calibrates the loop to the level you are targeting, so "what to expect" depends on whether you are interviewing for E4, E5, or higher.

Every mid-level candidate starts with a phone screen. This 45 minute screening round is your final gate before the onsite loop, where you typically solve 2 medium difficulty LeetCode problems using CoderPad, with about 35 minutes allocated to coding and 5 minutes for greetings and questions. That 35-minute budget for two problems is the single most important constraint to internalize. It means roughly 17 minutes per problem, including clarifying, coding, and testing.

For the onsite, the structure splits by level:

Level	Coding rounds	Other rounds
E4 / E5	2 (one AI-enabled)	System design or product architecture, behavioral, team match
E6	2 (one AI-assisted)	Architecture, design, behavioral (plus a Leadership Assessment before onsite)
E7+ / M1	1 (AI-assisted only)	Architecture, design, behavioral

For E4 and E5 candidates, the onsite is five rounds: two coding rounds, one system design or product architecture round, one behavioral round, and one team-matching conversation that is technically not scored but feeds the final decision. At the senior bar the balance shifts away from raw algorithms. For E7 and above, plus M1 manager candidates, the onsite has only one coding round, and it is the AI-assisted version, so there are no two-coding-round loops at the senior bar in 2026. E6 candidates also face an extra gate: there is a Leadership Assessment interview before the onsite, which replaces the standard phone screen, is half behavioral and half coding, and is where the hiring panel decides whether you are likely to make it through the rest of the loop.

One quirk that trips people up: Meta's coding round is famously run with code execution turned off in CoderPad. You cannot run your code against the examples. You have to trace it by hand, out loud, and convince the interviewer it works. Practice dry-running your solutions on paper, because a green test suite is not going to save you.

What the coding rounds actually test

Meta's rubric rewards four things in roughly this order: correctness, communication, speed, and code quality. Because you are solving two problems in 35 minutes, the interviewer is watching whether you can move. Candidates who spend eight minutes silently thinking before writing a line usually run out of runway on the second problem.

The pattern coverage at Meta is narrower than people fear. You do not need obscure segment trees or heavy dynamic programming. You need to be fast and fluent with:

Hash maps and sets for lookups and counting
Two pointers and sliding window on strings and arrays
Linked list manipulation
Binary search, including on answer spaces
Trees and graph traversal (BFS and DFS)
Greedy plus a hash map or heap

Most candidates over-index on hard problems and under-practice the boring skill that actually gets scored: explaining a straightforward optimal solution cleanly while typing. If you can talk and code at the same time without freezing, you are already ahead of most of the pool.

The AI-enabled coding round (what is new)

This is the headline change, and it is worth understanding precisely. Meta began rolling out its AI-enabled coding interview in October 2025, and the AI-enabled round replaced one of two traditional coding rounds at the onsite stage, while candidates still have one classic algorithm interview without AI alongside the new format.

The environment is different from the classic round. Candidates work in a CoderPad environment with a three-panel layout: a file explorer, a code editor, and an AI assistant chat window, where the AI can respond in the chat panel but cannot directly edit files, and the session is 60 minutes. So the AI is a pair, not an autopilot. You still own every keystroke.

Do not treat this as an easier round. The bar goes up when you have help. Interviewers want to see that you can direct the assistant, catch its mistakes, and defend your design choices rather than accepting whatever it emits. The people who do well use the AI to scaffold boilerplate and check edge cases, then make the architectural calls themselves. The people who do poorly paste in a suggestion, cannot explain it, and stall when asked why they chose it. Meta is not the only one moving this way; Google is testing its own AI-assisted rounds in 2026, so getting comfortable collaborating with a coding assistant under time pressure is now a transferable interview skill.

Problems Meta actually asks

Here are the highest-frequency Meta problems from our question bank, with the pattern each one drills. If you work through these and can re-derive them cold, you have covered most of what a Meta screen throws at you.

Problem	Pattern	Level
Longest Substring Without Repeating Characters	Sliding window	Mid/Senior
Median of Two Sorted Arrays	Binary search on partitions	Staff
Longest Palindromic Substring	Expand around center / DP	Mid/Senior
Add Two Numbers	Linked list traversal	Mid/Senior
Hand of Straights	Greedy + hash map	Mid/Senior
String to Integer (atoi)	Careful parsing / edge cases	Mid/Senior
Reverse Integer	Overflow handling	Mid/Senior
Zigzag Conversion	Simulation / index math	Mid/Senior

A few notes from running these all day. Longest Substring Without Repeating Characters is close to a canonical Meta warm-up: it tests whether you reach for a sliding window with a hash map instead of a brute-force nested loop, and whether you can keep the window invariant straight while talking. Median of Two Sorted Arrays is the one true hard problem here (marked staff for a reason); the log(min(m, n)) binary-search solution is hard to invent live, so know it cold rather than hoping to derive it.

Then there is a cluster of deceptively simple ones: Reverse Integer, String to Integer (atoi), and Zigzag Conversion. These look easy and are almost entirely about edge cases. atoi in particular is a communication test disguised as a parsing problem: leading whitespace, optional sign, non-digit termination, and 32-bit overflow clamping. With code execution off, the candidates who calmly enumerate those cases before writing pass, and the ones who "eyeball it" get burned. Hand of Straights is your greedy check: sort or count with a hash map, then repeatedly consume consecutive runs of groupSize.

A 3-week prep plan

You do not need three months. You need focused reps on the right patterns and, critically, reps saying your reasoning out loud.

Week 1: patterns. Spend it on hash maps, two pointers, sliding window, and linked lists. Do Longest Substring Without Repeating Characters, Add Two Numbers, and a handful of similar problems until the templates are automatic.

Week 2: breadth plus the hard cases. Add binary search (Median of Two Sorted Arrays), trees and graph BFS/DFS, and the edge-case problems (atoi, Reverse Integer, Zigzag Conversion). Start solving with a timer set to 17 minutes per problem.

Week 3: simulation. Do full 35-minute, two-problem sessions with code execution disabled. Narrate constantly. Do at least a few full company-style mock loops so the format itself stops being a variable on the day. Spend one session specifically practicing with an AI assistant open, so the AI-enabled round feels familiar rather than novel.

The candidates who convert Meta offers are rarely the ones who solved the most LeetCode. They are the ones who were fast, calm, spoke clearly, and did not need to run their code to trust it.

FAQ

How many coding rounds does Meta have?

It depends on level. E4 and E5 candidates get a phone screen plus two coding rounds at the onsite, one of which is now the AI-enabled format. E7 and above have just a single coding round, the AI-assisted one. There is always at least one classic no-AI algorithm interview for mid-level candidates.

Can I use an AI assistant in the Meta coding interview?

In the new AI-enabled round, yes. You get a three-panel CoderPad with a chat-based AI that can suggest and explain code but cannot edit your files directly. The traditional coding round still has no AI, so you need to be able to solve problems both ways.

How long is the Meta phone screen and how many problems?

The phone screen is 45 minutes, with about 35 minutes of actual coding. You typically solve two medium-difficulty problems, which works out to roughly 17 minutes each including clarifying questions and testing.

Is Meta's coding interview run without code execution?

Historically yes: Meta's CoderPad sessions have run with code execution turned off, so you cannot run your solution against test cases. Practice tracing your code by hand and reasoning through edge cases out loud, because you will need to convince the interviewer it works without a green checkmark.

What are the most common Meta coding questions?

High-frequency problems include Longest Substring Without Repeating Characters, Add Two Numbers, Longest Palindromic Substring, Median of Two Sorted Arrays, and String to Integer (atoi). They cluster around sliding window, linked lists, binary search, and careful edge-case handling rather than exotic algorithms.