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Salesforce·Software Engineer·Technical Phone Screen·Intermediate

IntermediatePrefer not to say
May 2026

Summary

Salesforce full-stack round that was heavier on functional programming concepts than I expected. The currying question sounds straightforward but the generalization part is where they actually want to see how you think.

Questions Asked (1)

Q1

Given a helper function addTwoNumbers(a, b) that returns a + b, implement a curried function addThreeNumbers so that addThreeNumbers(a)(b)(c) returns a + b + c. Then discuss how you'd generalize this to handle N numbers.

Algorithms & Data StructuresTechnical Trade-offs
Author's notes

The three-number part clicked pretty fast since you just chain the helper twice.

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AI HintsAI Generated

Suggested Approach

Start by implementing the curried function using nested arrow functions that leverage the provided addTwoNumbers helper. Then, discuss generalization to N numbers by proposing a recursive curried function that accumulates arguments until a termination condition, or by using a fixed-arity approach with a utility like curry. Emphasize clarity, reusability, and trade-offs between different implementations.

Pro tip: Mention that while recursion is elegant, it may lead to stack overflow for very large N; an iterative approach or using Function.length to determine arity can be more robust. Also, highlight that currying enables partial application, which is valuable in functional programming and event handling.

1. Implement addThreeNumbers

Write the curried function using nested arrow functions: const addThreeNumbers = a => b => c => addTwoNumbers(addTwoNumbers(a, b), c);. Ensure it correctly uses the helper.

2. Explain the currying concept

Briefly define currying and how it transforms a function with multiple arguments into a sequence of unary functions. Mention its benefits like partial application and composability.

3. Generalize to N numbers

Propose a recursive curried function that collects arguments until a specified arity is reached, then applies the reduction. Alternatively, suggest using a curry utility that supports variadic functions.

4. Discuss trade-offs and edge cases

Compare recursive vs. iterative approaches, consider performance and stack limitations, and address how to handle zero or one argument. Mention the importance of clear termination conditions.

5. Summarize and connect to real-world use

Conclude by emphasizing how currying aids in creating reusable, composable functions, and relate it to scenarios like configuring API calls or event handlers in Salesforce development.

Key Points to Mention

  • Currying definition and its distinction from partial application
  • Use of the provided addTwoNumbers helper to avoid reimplementing addition
  • Recursive currying implementation with an arity check
  • Trade-offs: recursion depth vs. iterative accumulation, performance considerations
  • Edge cases: handling zero arguments, ensuring correct arity, and type safety
  • Real-world applications: function composition, partial application in event handling, and functional programming paradigms

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