LinkedIn SWE Interview: Coding Interview Guide

Estimated read time: 7-9 minutes

Summary: LinkedIn software engineer (SWE) loop coding interviews validate coding across additional interviewers. Expect 45-60 minute live coding rounds focused on clean code, optimal approach, tests, debugging, and follow-up optimization. Use this guide to practice durable LinkedIn coding themes and follow-up patterns.

TL;DR + FAQ (read this first)

At-a-glance takeaways

• Loop coding interviews are often described as 45-60 minutes each.
• You should expect software engineers and live coding.
• Prepare for topics like graphs, intervals, data structures, recursion, backtracking, debugging, and optimization.
• Early-career loops are coding-heavy, while senior loops may add design and leadership elsewhere.
• Consistency matters because multiple interviewers may collect coding signal.

Quick FAQ

How is this different from the coding screen?
It is later in the loop and may repeat coding signal with deeper follow-ups.

How should I use the examples?
Use them as practice drills for the broad coding themes.

Do senior candidates still code?
Yes, coding remains likely, with additional design or leadership signal elsewhere.

What hurts candidates most?
Overcomplicating, not testing, and not adapting to follow-ups.

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1) How loop coding rounds work

Loop coding rounds are additional live coding interviews with software engineers. They may be virtual or onsite. You should expect algorithmic implementation plus follow-up optimization, debugging, or constraint changes.

Because multiple interviewers may collect signal, a repeatable process matters: clarify, outline, code, test, explain complexity, and adapt.

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2) Coding questions you may face

Use these examples as realistic LinkedIn coding practice tasks.

• Given a graph of professional connections, find the shortest path between two members. Then return the actual path, not only its length.
• Given meeting intervals, merge overlaps and then insert a new interval while preserving order.
• Implement a least recently used (LRU)-style cache. Then explain how you would test eviction and update behavior.
• Generate all valid combinations for a recursive search problem. Now add pruning to avoid unnecessary branches.
• Given a buggy solution to a counting problem, identify the failing edge case and fix the implementation.
• Given a feed of events, group and aggregate them by member id. Then optimize for streaming input.
• Take your working solution and improve either runtime or memory, explaining the tradeoff.

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3) Signals that compound across rounds

Strong candidates produce clean code and a clear trail of reasoning. They do not wait until the end to test. They explain why the approach works and what would break if constraints changed.

For senior candidates, the bar can include stronger tradeoff communication even in coding rounds. Make maintainability and clarity visible.

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4) Common failure modes

Overcomplicating early. Start with a clear baseline before optimizing.

Not testing. Practice edge cases and debugging instead of stopping at the first passing idea.

Ignoring follow-up constraints. Follow-ups often reveal the real signal.

Using generic parent-company assumptions. Keep preparation tied to LinkedIn-specific signal.

Failing to reset between rounds. Each interviewer is a fresh signal.

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5) How to prepare

• Practice graph search, intervals, caches, recursion, backtracking, and data structures.
• After every solution, add a follow-up optimization or debugging task.
• Run manual tests before discussing complexity.
• Practice multiple 45-60 minute rounds in one session.
• For senior roles, explain why your implementation is maintainable.

The loop is looking for a reliable pattern of technical execution, not one lucky solve.

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