How to Crack Anduril Coding Interviews in 2026

Anduril Industries builds defense technology products, from autonomous systems to AI-powered surveillance. Their coding interviews reflect this mission: practical, systems-aware, and focused on core algorithmic competency. The process typically involves multiple rounds of technical screening, often featuring LeetCode-style questions applied to real-world problem domains. Success requires a sharp, efficient approach to problem-solving.

By the Numbers — Difficulty Breakdown and What It Means

An analysis of 43 Anduril interview questions reveals a clear profile: 77% Medium difficulty (33 questions), with 12% each for Easy and Hard (5 questions each). This distribution is telling. Anduril isn't primarily testing obscure, complex algorithms; they are evaluating your mastery of fundamental computer science concepts under pressure. The high volume of Medium questions means you must be exceptionally fluent in applying core patterns to slightly novel situations. The presence of Hard questions indicates they will probe your limits on optimization and handling edge cases, especially for senior roles. Expect questions that feel like a step above classic LeetCode Easy but are grounded in practical implementation.

Top Topics to Focus On

The data shows a concentrated set of high-frequency topics. Depth over breadth is key here.

• Array & String (Often combined): The bedrock. Expect manipulations, sliding windows, and two-pointer techniques. Master in-place operations and efficient searching.
• Breadth-First Search (BFS): Critical for shortest path problems, level-order traversals, and anything involving exploring neighbors in a grid or graph. Know queue implementation inside out.
• Depth-First Search (DFS): Essential for exhaustive search, backtracking, and traversing all possibilities in a state space (like a matrix). Understand both recursive and iterative stack-based approaches.
• Matrix: Frequently the domain for BFS/DFS problems. You'll be navigating 2D grids, often with obstacles, to find paths, count islands, or propagate changes.

The most critical pattern across these topics is Graph Traversal on a Matrix. This combines Matrix, BFS, and DFS into a single, high-value skill. The classic "Number of Islands" problem is a perfect example.

from collections import deque

def numIslands(grid):
    if not grid:
        return 0

    rows, cols = len(grid), len(grid[0])
    islands = 0

    def bfs(r, c):
        queue = deque([(r, c)])
        grid[r][c] = '0'  # Mark as visited
        directions = [(1,0), (-1,0), (0,1), (0,-1)]

        while queue:
            row, col = queue.popleft()
            for dr, dc in directions:
                nr, nc = row + dr, col + dc
                if 0 <= nr < rows and 0 <= nc < cols and grid[nr][nc] == '1':
                    queue.append((nr, nc))
                    grid[nr][nc] = '0'

    for r in range(rows):
        for c in range(cols):
            if grid[r][c] == '1':
                bfs(r, c)
                islands += 1
    return islands

Preparation Strategy — A 4-6 Week Study Plan

Weeks 1-2: Foundation. Drill the top four topics exclusively. Solve 15-20 problems for each (Array/String, BFS, DFS, Matrix). Focus on pattern recognition. For each problem, implement it in your primary language, then re-implement the core algorithm in a second language to deepen understanding. Weeks 3-4: Integration & Difficulty Ramp. Start combining topics. Solve Matrix problems using BFS/DFS. Practice string problems that use array-based sliding windows. Begin tackling the Medium-difficulty questions from Anduril's known list. Time yourself. Weeks 5-6: Simulation & Review. In the final stretch, conduct mock interviews under timed conditions. Focus on clearly explaining your thought process before coding. Re-solve every problem you initially struggled with. Allocate time to review the core patterns for the 12% of Hard questions—understand the advanced optimization techniques (e.g., memoization for DFS, A* vs. BFS).

Key Tips

1. Communicate the Trade-off: When presenting a solution, explicitly state its time and space complexity. Anduril engineers work with resource-constrained systems; showing this awareness is crucial.
2. Start with a Brute Force: It's better to have a working, sub-optimal solution than no solution. Clearly state it, then iterate towards optimization. This demonstrates structured problem-solving.
3. Test with Edge Cases: Before declaring completion, walk through edge cases—empty input, single element, large values. Verbally state what you're checking for.
4. Practice on a Whiteboard: Do not only practice in an IDE. Write code by hand or on a blank document to simulate the interview environment where you lack auto-complete and syntax highlighting.

Your goal is to make solving Medium-difficulty Array, String, and Matrix traversal problems feel automatic. That fluency creates the mental bandwidth to handle the tricky twists Anduril interviewers will add.

Browse all Anduril questions on CodeJeet