For additional preparation, see our guide on Square, Cash App, and Block Interview Guide.
For additional preparation, see our guide on Block (Square) Software Engineer Interview Guide.
The behavioral round is where many candidates fall short — prepare with our behavioral interview guide.
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"description": "Technical interview preparation for Square and Block: payment processing infrastructure, POS hardware software, Bitcoin/Lightning (Spiral/TBD).",
"datePublished": "2026-03-19",
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"text": "Square interviews typically run 5–6 rounds: a recruiter screen (30 min), a technical phone screen (45–60 min), then 4–5 onsite or virtual rounds covering coding algorithms, system design, behavioral questions (STAR method), and for senior roles a leadership/culture-fit round. The full process takes 4–6 weeks from initial contact to offer."
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{
"@type": "Question",
"name": "What programming language should I use for Square interviews?",
"acceptedAnswer": {
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"text": "Square allows candidates to choose their preferred language. Most candidates use Python for its concise syntax, but Java, C++, and Go are equally accepted. Focus on clear, readable code rather than language tricks — interviewers evaluate your problem-solving approach, not language familiarity."
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"text": "Square coding interviews are considered high difficulty. Expect medium-to-hard LeetCode-style problems with a focus on algorithms, system design, and behavioral questions. Practice 100–200 problems on LeetCode with a focus on company-tagged problems before your interview loop."
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