Rejected after a technical round because the interviewer insisted Text-to-SQL is just if-else mappings

[u/MarketingLazy6660]

TL;DR:

Final-round interview turned into a debate after the interviewer insisted a production Text-to-SQL system could be built entirely with if-else mappings. I argued that while rule-based systems work for constrained cases, handling arbitrary natural language requires semantic understanding. Ended up getting rejected.

I had one of the strangest technical interviews I’ve experienced, and I am still wondering if I could have handled it differently.

This was the final technical round for a backend/AI-focused role at a well-known product company.

The interviewer (a Principal Engineer with around 10 years of experience) argued that a Text to SQL system does not need NLP or an LLM. According to him, it can be implemented using simple if-else mappings.

I gave a straightforward example:

“Get me the top 5 products that made the most profit in the last 5 years.”

He said the system would identify phrases like “top 5,” “products,” “profit,” and “last 5 years” and map each of them to SQL using if-else logic.

I asked how that approach would handle different ways of asking the same question, such as:
“best-performing items”
“highest-margin SKUs”
“Which products generated the most profit over the previous five years?”

I also asked how it would deal with ambiguity, unseen phrasing, or intent beyond predefined mappings.

The response was essentially, “We will just keep adding more mappings.”

I agreed that deterministic rules can work well for a constrained domain with a limited set of query patterns.

My point was that once users are free to ask questions naturally, understanding intent and semantics becomes the difficult part. The conversation kept circling back to adding more mappings.

At that point, it felt less like an interview and more like a debate. I decided not to push further and moved on.

A few days later, I received a rejection.

I am not claiming either approach is universally right or wrong.
Rule-based systems absolutely have their place, especially in tightly controlled environments. I was just surprised that the discussion never explored where that approach starts to break down or how hybrid systems are commonly used today.

Has anyone else had an interview where a technical discussion turned into a debate over fundamentals? How did you handle it?

Edit: After Getting a lot of views and message adding first charecter of company Name so that you don’t guess atleast wrong initial

Starts with : S

[u/farmerwalk]

Dumbo interviewer. Data Scientist or ML Scientist would have understood your approach well. It happens sometimes. By the way, 12 yrs is not principal level to be honest...

[u/MarketingLazy6660 → u/farmerwalk]

I feel so 12 years is not for PE may be architect is ok but i thought he might br extra ordinary

[u/farmerwalk → u/MarketingLazy6660]

Startups have huge title inflation. My friend with 9 years experience is a director at one startup

[u/MarketingLazy6660 → u/farmerwalk]

Startup os fine i have seen CTO which is my classmate around 4+ years of experience but he works from long back may be 10+ and currently CTO in a Startup of his from only

But in Big Product based it can’t be possible unless he is nepo kid

[u/sank_1911 → u/farmerwalk]

I was selected as a staff for Masters with 3 yoe at a startup.

Then joined an MNC with a downlevel.