SP and DSE Practice Exercises: Build a Technical Explanation

The exercises below are original practice material, written from general programming concepts rather than a recalled employer paper. They are not copies of an Infosys paper, a confirmed Specialist Programmer or Digital Specialist Engineer sequence, or evidence that a specific role will ask these questions. Use the official Infosys careers page and the current role communication for live process information.

Exercise one: make a duplicate detector explainable

Given a list of identifiers, return the identifiers that occur more than once. Start by describing a nested-loop approach. Then use a map or set to improve the solution. Explain what the program should return for an empty list and for a list where every identifier is the same.

The learning objective is not a secret question pattern. It is the ability to explain data choice, edge cases, and complexity.

Exercise two: inspect a service failure

Imagine a small web service returns an error only after a new configuration value is deployed. Write a debugging plan before proposing a fix. A sensible plan can include reproducing the error safely, checking logs for the failing boundary, comparing the new configuration with the prior version, and testing a narrow change before broader rollout.

State what evidence would make you stop and ask for help. This shows judgement; it is not a prediction about an employer's production system.

Exercise three: discuss a project trade-off

Take a project from your resume and choose one decision you made under constraints. Explain the alternatives, the reason for your choice, the drawback, and what you would change after receiving more time or data. Avoid claiming that an interviewer wants a particular framework or architecture.

Build a repeatable answer review

After a practice session, ask:

• Did I define the input and output clearly?
• Did I explain why the algorithm terminates?
• Did I name at least one failure case?
• Did I distinguish what I know from what I would verify?
• Did I describe my personal contribution truthfully?

Write the answer once, then say it aloud in two minutes. If the explanation becomes vague, return to the code or project documentation.

Keep role facts separate from practice

Titles, eligibility, assessment stages, compensation, and timelines are employer-controlled facts. They should come from the current official role posting or written invitation, not from a practice page. The official Infosys careers page and the written application communication are the employer sources to consult for those current materials; neither turns this exercise guide into a role specification.

One more way to check an answer

Pair with a classmate only after each of you has attempted an exercise alone. Exchange explanations rather than just final code. The listener should be able to ask what happens at an input boundary, why a data structure was chosen, and how the result would be tested. If either explanation depends on a copied solution, rebuild it from the stated input before moving on.