Profound·Software Engineer·Take-home Assignment·Intermediate

Intermediate

Jun 2026

Summary

Take-home coding exercise for a Software Engineer role at Profound. The task was to build a CLI script that walks through a full credit management API workflow, from account creation to balance validation. Pretty self-contained but had some gotchas around auth and error handling.

Questions Asked (1)

Build a command-line script that runs a full workflow against a sandbox credit management API: create an account, add credits, check balance, spend credits, check balance again, and assert the final balance is mathematically correct.

API & IntegrationsTechnical Trade-offs

Author's notes

The part that tripped me up first was figuring out the actual request format.

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AI HintsAI Generated

Suggested Approach

Start by outlining the script's structure: a sequence of API calls with error handling and assertions. Emphasize idempotency, test isolation, and clear logging. Then discuss trade-offs like using a real sandbox vs. mocking, and how to handle asynchronous operations.

Pro tip: Use a unique account identifier per run to avoid state pollution, and always clean up resources in a finally block. This shows you think about test hygiene and reliability.

1. Clarify Requirements and Constraints

Ask about the API's authentication, rate limits, and whether the sandbox persists state. Confirm the expected mathematical correctness (e.g., initial balance + added - spent = final).

2. Design the Script Structure

Outline a modular script with functions for each API call, centralized error handling, and configuration via environment variables. Plan to use a unique account ID per run.

3. Implement API Interactions

Write code to create an account, add credits, check balance, spend credits, and check balance again. Include retries for transient failures and log each step.

4. Add Assertions and Validation

After each operation, validate the response. At the end, assert that final balance equals initial + added - spent, with a clear error message if not.

5. Discuss Trade-offs and Edge Cases

Explain choices like using a real sandbox vs. mocking, handling concurrent modifications, and ensuring idempotency. Mention cleanup and reporting.

Key Points to Mention

Idempotency and unique account IDs to avoid test interference
Error handling and retries for network issues
Assertion strategy: exact balance check with tolerance for floating-point if needed
Logging and observability for debugging
Cleanup of created resources (e.g., delete account) in a finally block
Trade-offs between integration testing with sandbox vs. unit testing with mocks

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