Fiserv SDE-1 Junior

What is null vs undefined (JS) / nullable (C#)?

undefined = missing; null = empty value in JS. C# nullable types allow null safely. ShopNest treats missing coupon as null, not a fake empty string.

Fiserv rounds often probe: Payments domain.

Themes commonly reported in public MNC interview experiences (AmbitionBox / LinkedIn / Glassdoor-style). Practice aloud; keep answers this short in the real round.

More Fiserv SDE-1 questions

Explain OOP in one minute with an example.
Array vs List — when to use which?
What is time complexity of binary search?
Difference between == and Equals in C# / === in JS?
What is a primary key vs unique key?
HTTP GET vs POST?

All SDE-1 questions

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