@sahilgupta2175
Sahil Gupta
@sahilgupta2175Bangalore, IndiaJoined December 2025
Programmer Analyst Trainee at Cognizant
About
I'm a passionate software engineer and full-stack MERN developer who loves to turn ideas into scalable, user-centric applications. I have hands-on experience in building modern web solutions using React, Node.js, Express.js, MongoDB, following clean architecture and best development practices. My experience in the Cognizant Healthcare Product Consulting (HPC) program has given me hands-on exposure to SQL, PL/SQL, U.S. healthcare payer systems and TriZetto Facets, and has helped me to further develop my skills in working with enterprise software in domain-driven environments. I enjoy tackling complex technical problems, constantly learning, and building reliable applications that deliver business value.
Available for
Freelance work
Comments
SG
This is a great addition, thanks for pointing it out! I kept the article focused on the "expand vs collect" mental model, but you're right that the enumerable-properties-only behavior (and the Math.max call-stack limit) are exactly the kind of thing that trips people up once they start using spread on real objects instead of plain literals. Updated the post to include both - appreciate you taking the time to write this out.
SG
Really appreciate this - genuinely useful corrections, adding all four to the post: Good catch on -0/+0 - I only mentioned the NaN side of SameValueZero, missed that the zeros collapse the other direction. The WeakMap point is the one I should've led with, actually. "Cache by object reference" without mentioning the strong-reference leak risk is incomplete advice. The JSON one is brutal in practice because it fails silently - no error, just an empty payload. Worth its own callout. Object.create(null) is a nice addition for the "don't need full Map, just want no prototype" case. Updated the article with all of these. Thanks for reading closely enough to catch this.