At&t | Software Engineer | Los Ang - At&t

Summary

I successfully navigated a streamlined and professional interview process at AT&T for a Software Engineer role in Los Angeles, ultimately receiving an offer after a phone screen and an on-site interview.

Full Experience

Interview Process

My interview process for the Software Engineer position at AT&T was streamlined and professional. I began with a behavioral and technical screening phone call. Following a successful phone screen, I was invited for an on-site interview.

Upon arriving at the AT&T corporate office, I was met and escorted upstairs to the 10th floor where the interview was held. I entered a room where three software engineers were seated at the table. After a brief introduction and some small talk, we quickly moved into the technical portion of the interview.

Technical Discussion

The engineers asked me about my familiarity with various technologies, and I discussed Docker, AWS, Kubernetes, Mongo, and MySQL, among others. They followed up with specific questions about each technology. We also covered programming languages, where I elaborated on Java, C++, Golang, Node.js, React, and Angular, discussing their pros, cons, quirks, and various trivia related to them.

Beyond specific technologies and languages, I was posed architectural questions, including how I would handle scalability problems given limited hardware capacity. I explained approaches such as using CDNs, implementing caching strategies, optimizing the slowest parts of software, and employing load balancing techniques.

The Whiteboard Part

The core algorithm challenge involved a variation of the LeetCode problem "Best Time to Buy and Sell Stock" (#121), adapted to a scenario involving buckets of corn instead of stocks. The problem asked me to find the maximum profit by completing at most one transaction, meaning I could buy one bucket and sell one bucket, but not sell before buying.

I initially developed an O(n^2) solution, which I meticulously wrote out on the whiteboard. During this process, I actively discussed my thought process with the engineers. Through further discussion and refinement, I was able to optimize my solution down to an O(n) approach, which seemed to satisfy the interviewers.

Overall Thoughts

My overall interview experience with AT&T was professional and efficient. I received an offer shortly after my on-site interview. The office environment appeared to be a great place to work, and the software team I met seemed very sharp and friendly. I'm looking forward to this new chapter!

Interview Questions (1)

Best Time to Buy and Sell Stock

Data Structures & AlgorithmsEasy

You are given an array prices where prices[i] is the price of a given stock on the i^th day.

You want to maximize your profit by choosing a single day to buy one stock and choosing a different day in the future to sell that stock.

Return the maximum profit you can achieve from this transaction. If you cannot achieve any profit, return 0.

Example 1:

Input: prices = [7,1,5,3,6,4]
Output: 5
Explanation: Buy on day 2 (price = 1) and sell on day 5 (price = 6), profit = 6-1 = 5.
Not 7-1 = 6, as selling price needs to be larger than buying price.

Example 2:

Input: prices = [7,6,4,3,1]
Output: 0
Explanation: In this case, no transactions are done and the max profit = 0.

AT&T | Software Engineer | Los Angeles | August 2019 [Offer]