Leap Tools·Software Engineer·Technical Phone Screen·Intermediate

IntermediatePending

Jul 2026Remote

Summary

Cleared round 1 at Leap Tools (live coding, pagination with edge cases) and got bumped to a round with a senior dev. The recruiter's briefing was basically nothing: write code, start simple, get more complex, go fast. Posting here because I have no idea what to actually prep.

Questions Asked (1)

Implement a pagination feature starting from a basic version, then extend it as more complex requirements are layered on.

Algorithms & Data StructuresTechnical Trade-offs

Author's notes

This is what round 1 was built around and probably bleeds into round 2 as well.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the requirements and constraints, then implement a basic pagination solution (e.g., offset-based) and iteratively refine it as new requirements are introduced. At each iteration, discuss trade-offs and potential optimizations, ensuring the solution remains scalable and maintainable.

Pro tip: Always consider edge cases like empty results, out-of-range pages, and concurrent data changes; mentioning these proactively shows attention to detail and production readiness.

1. Clarify Requirements

Ask questions to understand the expected scale, data source, and specific pagination needs (e.g., page size, sorting, filtering). This ensures you build the right solution from the start.

2. Implement Basic Pagination

Choose a simple approach like offset-based pagination and implement it with clear, modular code. Explain how it works and its limitations.

3. Extend with New Requirements

As additional requirements are layered (e.g., cursor-based pagination, infinite scroll, performance constraints), adapt your solution step by step, discussing the changes needed.

4. Analyze Trade-offs

Compare different pagination strategies (offset vs. cursor, server-side vs. client-side) in terms of performance, consistency, and complexity. Justify your choices.

5. Test and Validate

Outline how you would test the pagination feature, including edge cases and potential failure modes, to ensure robustness.

Key Points to Mention

Offset-based pagination: simple but can be inefficient for large datasets and may lead to inconsistent results if data changes.
Cursor-based pagination: better performance and consistency for large, dynamic datasets, but more complex to implement.
Handling edge cases: empty results, invalid page numbers, and concurrent data modifications.
Performance considerations: indexing, query optimization, and caching strategies.
API design: how pagination parameters are passed and responses are structured (e.g., links, cursors).
Scalability: how the solution holds up as data grows and traffic increases.

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.