Five AT&T TDP Software Engineer reports, with five practice questions.

Coverage: New-grad and intern roles · OA through final round · November 2024 to October 2025

The short version

If you're preparing now, don't spend all your time on coding. SQL showed up in both detailed OA reports.

1. Plan for two coding questions and one SQL question. Both detailed OA reports had this mix.
2. Expect easy to medium coding. One candidate called the test easy. Another called both coding questions medium.
3. Practice debugging. Two candidates got an easy coding question followed by a debugging task in the live technical round.
4. Review basic OOP. Candidates were asked to explain OOP ideas and talk about tools they had used.
5. Prepare behavioral stories. Teamwork, conflict, interests, and past projects all came up.

A good prep session: two coding questions, one SQL query, one short debugging exercise, four OOP concepts, and four behavioral stories.

OA questions we could verify

2024 set

1. Counting Triplets Divisible by D: Count triplets i < j < k whose values add up to a multiple of d.
2. Project Estimates: Count distinct pairs of project costs with a target absolute difference.
3. Advertising System Failures Report: Join customer, campaign, and event data. Return customers with more than three failed events.

The candidate called this set easy. The listed setup gave candidates 60 minutes and required a webcam. One triplet example had a bad index, so the FastPrep version keeps the clear rule and fixes the typo.

2025 set

1. 3Sum: The report called it a variation, but did not save the changed rule. The practice page covers the core pattern without making up a twist.
2. Break a Palindrome: Change one character so the string is no longer a palindrome, while keeping the answer as small as possible.
3. Unknown SQL question: The candidate remembered finishing it, but not the tables or requested result.

5 candidate snapshots

01: 2024 new-grad intern OA

Three questions: Counting Triplets, Project Estimates, and one SQL report. The candidate called the set easy. This report saved the most useful question detail.

02: 2025 new-grad OA

Three questions again: a 3Sum variation, Break a Palindrome, and one SQL question. The candidate rated both coding tasks as medium. The SQL prompt was not remembered.

03: Recruiter screen, then coding and OOP

The recruiter call lasted about 30 minutes and was fully behavioral. The technical round lasted about one hour with two TDP engineers. It included one easy algorithm question and basic OOP questions. SQL appeared in the OA but not in this live round.

04: Coding, debugging, then a relaxed final

A full-time New Jersey candidate got one easy algorithm question and one debugging task in an online editor. The final felt relaxed and conversational, but it was still behavioral.

05: Coding, debugging, and application basics

Another candidate reported one easy algorithm question, one easy debugging task, and questions about OOP and technologies used to build applications.

Two separate candidates mentioned debugging, so it deserves real prep time. Still, the live round was not identical for everyone.

What to practice

Coding and SQL

1. Do a 60-minute mock with two easy-to-medium coding questions and one SQL question.
2. Review arrays, hash maps, two pointers, strings, and remainder counting.
3. Write joins, GROUP BY, COUNT, and HAVING without looking up basic syntax.

Live technical

1. Read a short piece of code, find the bug, and explain the fix out loud.
2. Explain encapsulation, inheritance, polymorphism, and abstraction in simple words.
3. Ask clarifying questions before you start coding.

Behavioral

1. Prepare short STAR stories about teamwork, conflict, failure, and a surprise change.
2. Have a clear answer for why AT&T, why TDP, and which software areas interest you.
3. Keep each story concrete: what happened, what you did, and what changed.

Final checklist

☐ Solve the five linked FastPrep questions.

☐ Practice one coding + SQL set under time pressure.

☐ Debug code while explaining your thinking.

☐ Review basic OOP in plain English.

☐ Prepare four short behavioral stories.

This roundup combines five candidate reports. The process can change by year, role, and location. If your recent experience was different, share what changed and what you can verify.