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Global Infotech Software Engineer Interview Guide

Global Infotech Software Engineer interview guide: reported rounds, questions and how candidates describe the process.

The 60-second brief

At Global Infotech, a Software Engineer plays a pivotal role in designing, developing, and maintaining robust, scalable software solutions that drive business transformation. As a key technical contributor, you will work on enterprise-level applications, integration platforms, and client-facing web solutions. The engineering team is responsible for translating complex client requirements into high-performing, clean, and maintainable code. This role is highly critical because Global Infotech focuses on delivering high-availability IT services and software products across various domains. You will have the opportunity to influence system architecture, optimize database workflows, and build seamless user interfaces.

This guide is scoped to a Software Engineer candidate at Global Infotech.

Focus areas

  • PHP
  • MySQL
  • JavaScript

The Global Infotech interview process

Global Infotech candidates report 3 rounds over 3-5 weeks. The stages below are what candidates describe, not a published process.

Written Aptitude & Coding Test

Preliminary screening round with multiple-choice questions on quantitative aptitude, logical reasoning, and basic programming challenges.

What to demonstrate

  • Preliminary screening round with multiple-choice questions on quantitative aptitude, logical reasoning, and basic programming challenges
  • Depth in PHP

How to prepare

  • Answer aloud and timed: Explain the four pillars of Object-Oriented Programming (OOPs) and how you have implemented them in your past projects.
  • Answer aloud and timed: What is the difference between an abstract class and an interface in PHP (or your preferred backend language)?

Technical Interview

Deep-dive discussion focusing on core technical stack, understanding of OOPs, and past project walkthrough.

What to demonstrate

  • Deep-dive discussion focusing on core technical stack, understanding of OOPs, and past project walkthrough
  • Depth in PHP

How to prepare

  • Answer aloud and timed: How do you handle session management and security (like SQL injection and XSS prevention) in a web application?
  • Answer aloud and timed: Explain the life cycle of a backend request from the client browser to the database and back.

HR & Situational Round

Final conversation addressing career goals, behavioral alignment, situational problem-solving, and salary expectations.

What to demonstrate

  • Final conversation addressing career goals, behavioral alignment, situational problem-solving, and salary expectations
  • Depth in PHP

How to prepare

  • Answer aloud and timed: What are magic methods in PHP, and when would you use them?
  • Answer aloud and timed: How do you optimize a slow-running MySQL query? Explain the role of indexing.

Where candidates lose points

Master Your Resume Projects

Do not list any project on your resume that you cannot explain in detail. Be ready to draw the technical architecture, explain the database schema, and justify your choice of technology.

Practice Time Management for Aptitude Tests

Since the initial screening round features a 30-question aptitude test, practice solving logical puzzles and quantitative questions quickly. Accuracy and speed are key.

Do not leave any questions blank on the written aptitude test

Since there is no negative marking, making an educated guess is always better than leaving a blank answer.

Questions & practice

Explain how asynchronous programming works in JavaScript using Promises and Async/Await.

Medium · Frontend Basics & Web Integration

Approach

  1. Say what the runtime actually does before reasoning about the code.
  2. Name what is shared across threads and what owns each piece of state.
  3. Identify the window where an invariant is briefly untrue.
  4. Distinguish a value from a reference to it, and say which one you handed out.

Follow-up

  • What happens if two callers reach this at the same time?
  • Where could this allocate more than you expect?

Given an array of integers, write a function to find the duplicate elements.

Medium · Logical Aptitude & Coding

Approach

  1. Restate the input: its shape, its size, and what is guaranteed about it.
  2. Name the brute-force solution and its complexity before improving on it.
  3. Choose the data structure from the access pattern, not from familiarity.
  4. State the target complexity and say which constraint rules the naive version out.

Follow-up

  • How does this change if the input no longer fits in memory?
  • What is the worst case, and how likely is it on real data?

How do you reverse a string without using built-in language functions?

Medium · Logical Aptitude & Coding

Approach

  1. Restate the input: its shape, its size, and what is guaranteed about it.
  2. Name the brute-force solution and its complexity before improving on it.
  3. Choose the data structure from the access pattern, not from familiarity.
  4. State the target complexity and say which constraint rules the naive version out.

Follow-up

  • How does this change if the input no longer fits in memory?
  • What is the worst case, and how likely is it on real data?

Solve a logical puzzle: You have 3 boxes, one containing only apples, one containing only oranges, and one con

Medium · Logical Aptitude & Coding

Solve a logical puzzle: You have 3 boxes, one containing only apples, one containing only oranges, and one containing both. All boxes are mislabeled. How can you label them correctly by opening only one box?

Approach

  1. Restate the input: its shape, its size, and what is guaranteed about it.
  2. Name the brute-force solution and its complexity before improving on it.
  3. Choose the data structure from the access pattern, not from familiarity.
  4. State the target complexity and say which constraint rules the naive version out.

Follow-up

  • How does this change if the input no longer fits in memory?
  • What is the worst case, and how likely is it on real data?

What is the time complexity of binary search compared to linear search, and when should each be used?

Medium · Logical Aptitude & Coding

Approach

  1. Restate the input: its shape, its size, and what is guaranteed about it.
  2. Name the brute-force solution and its complexity before improving on it.
  3. Choose the data structure from the access pattern, not from familiarity.
  4. State the target complexity and say which constraint rules the naive version out.

Follow-up

  • How does this change if the input no longer fits in memory?
  • What is the worst case, and how likely is it on real data?

How do you optimize a slow-running MySQL query? Explain the role of indexing.

Medium · Database Design & SQL

Approach

  1. Name the grain you start from and join outward from it.
  2. Check whether any join is one-to-many before aggregating, or the sums inflate.
  3. Say which index the query would use, and what makes it unusable.
  4. Handle the rows that do not match: that is usually the actual question.

Follow-up

  • How does the query change if that join becomes one-to-many?
  • What happens to this when the table is ten times larger?

What is database normalization, and when would you choose to denormalize a database?

Medium · Database Design & SQL

Approach

  1. Name the grain you start from and join outward from it.
  2. Check whether any join is one-to-many before aggregating, or the sums inflate.
  3. Say which index the query would use, and what makes it unusable.
  4. Handle the rows that do not match: that is usually the actual question.

Follow-up

  • How does the query change if that join becomes one-to-many?
  • What happens to this when the table is ten times larger?

Write a query to find the second-highest salary from an employee table.

Medium · Database Design & SQL

Approach

  1. Name the grain you start from and join outward from it.
  2. Check whether any join is one-to-many before aggregating, or the sums inflate.
  3. Say which index the query would use, and what makes it unusable.
  4. Handle the rows that do not match: that is usually the actual question.

Follow-up

  • How does the query change if that join becomes one-to-many?
  • What happens to this when the table is ten times larger?

Explain the difference between JOIN, LEFT JOIN, and RIGHT JOIN with practical examples.

Medium · Database Design & SQL

Approach

  1. Name the grain you start from and join outward from it.
  2. Check whether any join is one-to-many before aggregating, or the sums inflate.
  3. Say which index the query would use, and what makes it unusable.
  4. Handle the rows that do not match: that is usually the actual question.

Follow-up

  • How does the query change if that join becomes one-to-many?
  • What happens to this when the table is ten times larger?

Explain the four pillars of Object-Oriented Programming (OOPs) and how you have implemented them in your past

Medium · Core Backend & Object-Oriented Programmi

Explain the four pillars of Object-Oriented Programming (OOPs) and how you have implemented them in your past projects.

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. Work from the requirement backwards to the design.

Follow-up

  • What assumption would you test first?
  • How would you know your answer was wrong?

What is the difference between an abstract class and an interface in PHP (or your preferred backend language)?

Medium · Core Backend & Object-Oriented Programmi

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. Work from the requirement backwards to the design.

Follow-up

  • What assumption would you test first?
  • How would you know your answer was wrong?

Explain the life cycle of a backend request from the client browser to the database and back.

Medium · Core Backend & Object-Oriented Programmi

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. Work from the requirement backwards to the design.

Follow-up

  • What assumption would you test first?
  • How would you know your answer was wrong?

What are magic methods in PHP, and when would you use them?

Medium · Core Backend & Object-Oriented Programmi

Approach

  1. Clarify what is being asked and what a complete answer contains.
  2. State your assumptions explicitly before working the problem.
  3. Say what you would check first and why it is the highest-information step.
  4. Work from the requirement backwards to the design.

Follow-up

  • What assumption would you test first?
  • How would you know your answer was wrong?

Design a database schema for a basic e-commerce system, highlighting the primary and foreign key relationships

Medium · Database Design & SQL

Design a database schema for a basic e-commerce system, highlighting the primary and foreign key relationships.

Approach

  1. Fix the scope first: who calls this, how often, and what they do when it fails.
  2. Name the read and write paths separately; they rarely have the same bottleneck.
  3. Choose a partition key and say what query it makes expensive.
  4. State the consistency you need, and where you are willing to be stale.

Follow-up

  • What breaks first when traffic grows ten times?
  • How does this behave when that dependency is down for an hour?

What is the difference between let, var, and const in JavaScript?

Medium · Frontend Basics & Web Integration

Approach

  1. Say who the caller is and what they do when the call fails halfway.
  2. Define the identity of a request so a retry cannot double-apply it.
  3. Separate accepted, pending, failed and confirmed; they are different facts.
  4. Design the error taxonomy before the success shape; callers branch on it.

Follow-up

  • What happens if the caller retries after a timeout?
  • How does a client discover it is on an old version of this contract?

How does the browser render a webpage? Explain the relationship between HTML, CSS, and the DOM.

Medium · Frontend Basics & Web Integration

Approach

  1. Say who the caller is and what they do when the call fails halfway.
  2. Define the identity of a request so a retry cannot double-apply it.
  3. Separate accepted, pending, failed and confirmed; they are different facts.
  4. Design the error taxonomy before the success shape; callers branch on it.

Follow-up

  • What happens if the caller retries after a timeout?
  • How does a client discover it is on an old version of this contract?

How do you make a web page responsive, and what are the key differences between Flexbox and CSS Grid?

Medium · Frontend Basics & Web Integration

Approach

  1. Say who the caller is and what they do when the call fails halfway.
  2. Define the identity of a request so a retry cannot double-apply it.
  3. Separate accepted, pending, failed and confirmed; they are different facts.
  4. Design the error taxonomy before the success shape; callers branch on it.

Follow-up

  • What happens if the caller retries after a timeout?
  • How does a client discover it is on an old version of this contract?

What is event bubbling and event capturing in JavaScript?

Medium · Frontend Basics & Web Integration

Approach

  1. Say who the caller is and what they do when the call fails halfway.
  2. Define the identity of a request so a retry cannot double-apply it.
  3. Separate accepted, pending, failed and confirmed; they are different facts.
  4. Design the error taxonomy before the success shape; callers branch on it.

Follow-up

  • What happens if the caller retries after a timeout?
  • How does a client discover it is on an old version of this contract?

Exports duplicate a row range about once a week

Hard · leases · clock skew · idempotency

Roughly once a week an export writes a file containing a duplicated range of rows. The affected job_run rows show attempt = 1, status = succeeded, one started_at, and a lease_owner naming a different host from the one whose logs show the job starting. Leases last 30 seconds and are heartbeated every 10 from inside the handler; lease_expires_at is computed on the worker and compared against the database's now(). Find the mechanism, and give a fix that holds even if you cannot fix the clocks.

Approach

  1. Start from the fact that eliminates the obvious answer. attempt = 1 means no retry was recorded, so this is not a re-run after failure; two workers ran the same row concurrently and the takeover path never touched the counter. lease_owner naming a host other than the one that started the job is the same statement from the other side.
  2. Enumerate the mechanisms that cause a premature takeover, then find the signal that separates them. Either the lease genuinely expired because the heartbeat did not fire, which is what happens when the heartbeat runs on the handler's own thread and the handler makes a long blocking call, or it only appeared expired because two clocks disagree, since lease_expires_at is written from the worker's clock and evaluated against the database's. The discriminator is the distribution: incidents clustered on the longest exports indict the heartbeat, incidents clustered on one host indict skew. Measure both, and measure each host's offset against the database directly.
  3. Read the reclaim query precisely. In PostgreSQL now() is transaction start time, not statement time, so a reclaimer holding a long transaction compares against an older timestamp than expected; clock_timestamp() is the statement-time function. This is worth ruling in or out before you redesign anything, because it changes which rows look expired.
  4. Remove the second clock rather than trying to synchronise it. Issue and extend the lease in the database, with lease_expires_at = now() + interval '30 seconds' in both the claim and the heartbeat, so exactly one clock is ever compared and worker skew stops mattering to this predicate.

Follow-up

  • The displaced worker has already streamed half the file to object storage. What makes that side effect safe to repeat?
  • You now count takeovers. What alert fires on that counter, and at what threshold?

Suggested practice checklist

Built from the rounds and topics Global Infotech candidates report.

Day 1 — Map the Global Infotech loop

  • Write out the reported sequence: Written Aptitude & Coding Test, Technical Interview, HR & Situational Round.
  • For each round, write one sentence on what it is judging, from the description above, and mark the one you are least ready for.

Deliverable: A one-page map of the 3 reported rounds, with the weakest marked.

Day 2 — Work PHP

  • Spend the session on PHP, which Global Infotech candidates report being tested on.
  • Write one worked example in PHP and time yourself on it.

Deliverable: One timed worked example in PHP.

Day 3 — Work MySQL

  • Spend the session on MySQL, which Global Infotech candidates report being tested on.
  • Write one worked example in MySQL and time yourself on it.

Deliverable: One timed worked example in MySQL.

Day 4 — Work JavaScript

  • Spend the session on JavaScript, which Global Infotech candidates report being tested on.
  • Write one worked example in JavaScript and time yourself on it.

Deliverable: One timed worked example in JavaScript.

Day 5 — Answer out loud: Core Backend & Object-Oriented Programming

  • Answer aloud, timed: Explain the four pillars of Object-Oriented Programming (OOPs) and how you have implemented them in your past projects.
  • Answer aloud, timed: What is the difference between an abstract class and an interface in PHP (or your preferred backend language)?

Deliverable: Spoken answers to 2 reported Core Backend & Object-Oriented Programming question(s), under time.

Day 6 — Answer out loud: Database Design & SQL

  • Answer aloud, timed: How do you optimize a slow-running MySQL query? Explain the role of indexing.
  • Answer aloud, timed: Design a database schema for a basic e-commerce system, highlighting the primary and foreign key relationships.

Deliverable: Spoken answers to 2 reported Database Design & SQL question(s), under time.

Day 7 — Answer out loud: Frontend Basics & Web Integration

  • Answer aloud, timed: What is the difference between let, var, and const in JavaScript?
  • Answer aloud, timed: Explain how asynchronous programming works in JavaScript using Promises and Async/Await.

Deliverable: Spoken answers to 2 reported Frontend Basics & Web Integration question(s), under time.

Behavioural preparation

Behavioural rounds judge the decision you made and what it cost.

How do you handle session management and security (like SQL injection and XSS prevention) in a web application

Medium · Core Backend & Object-Oriented Programmi

How do you handle session management and security (like SQL injection and XSS prevention) in a web application?

Approach

  1. Pick a story where you made the decision, not one where you watched it.
  2. State the situation in two sentences and spend the rest on the reasoning.
  3. Give the blast radius: what could have broken, and what you measured.
  4. Name the disagreement and how you resolved it with evidence.

Follow-up

  • What would you do differently if you ran that again?
  • How did you know your change caused the improvement?

Unblock an engineer without taking the keyboard

Easy · mentoring · leases · at-least-once

A teammate has spent two days on a job handler that occasionally writes duplicate rows. They are certain the queue is delivering twice by mistake. You suspect a lease expiring under a slow handler, so the job is running concurrently with itself. Describe how you have unblocked someone in this position: what you asked before offering a hypothesis, what you showed them rather than told them, and what you left them owning. Then say what you would do if their theory turned out to be the right one.

Approach

  1. Ask before diagnosing, and ask for things answerable from data they already have: the attempt count on the job rows that produced duplicates, the handler's observed duration against its lease expiry, and whether the duplicate rows share a natural key that a unique constraint could have caught.
  2. Teach the shape rather than the answer. A lease cannot distinguish a dead worker from a slow one, so a handler that outruns its lease is running twice by design, and deploys deliver the other half by killing handlers mid-run on every rollout. Both of their candidate theories produce identical duplicate rows, which is why the evidence has to come from timings rather than from argument.
  3. Hand over a checklist they execute: a natural key on every write the handler performs so the second copy collides rather than appends, the record of intent written before any external effect, a lease heartbeat while running, and the metric that shows it working.
  4. Keep ownership with them deliberately. Pair on the first write, then step back; if you finish it yourself you have closed one ticket and left the same person stuck on the next redelivery.

Follow-up

  • How would you distinguish a genuine double-delivery from a lease expiry using only the data already stored?
  • Their handler calls an external endpoint before recording that it did. What do you tell them to change first?

Estimate work you have never done and defend the range

Hard · estimation · backfills · expand-contract

You are asked to estimate a change you have never attempted: add a column to a 100-million-row table, populate it, move reads across, and drop the old shape. Give a range with the assumptions that generate it, including batch size, the signal your backfill throttles on, and wall-clock hours, and name the three unknowns that would move the number most. Then describe a real estimate you gave under comparable ignorance: how you expressed its uncertainty, what you committed to, and how wrong you turned out to be.

Approach

  1. Decompose into independently deployable steps before estimating anything: add the column nullable, write both shapes, backfill in batches, verify, move reads, stop writing the old shape, drop it. That is four deploys spread over days, and the calendar estimate is dominated by them rather than by the loop's runtime.
  2. Do the arithmetic aloud for the part that has arithmetic in it: batch size times number of batches times per-batch duration, at a write rate the primary can absorb alongside roughly 1.2k writes per second of production traffic. The loop is throttled by replication lag and lock waits, not by how fast it can issue statements.
  3. Price the schema step by its lock rather than its statement duration. In PostgreSQL an ALTER TABLE taking ACCESS EXCLUSIVE waits for every open transaction on that table while later queries queue behind it, so a millisecond change issued during a thirty-second analytics query stalls that table for thirty seconds. Adding a nullable column with a non-volatile default avoids a rewrite from version 11; a new index wants CREATE INDEX CONCURRENTLY, which cannot run inside a transaction block and leaves an invalid index behind if it fails.
  4. Express the answer as a range whose endpoints each trace to a stated assumption, then name the cheapest experiment that collapses it, which is almost always running one real batch against the real table and multiplying.

Follow-up

  • How do you verify the backfill genuinely finished, given rows written by production traffic while it ran?
  • Where does the backfill resume from after a worker is killed mid-batch, and what makes that resume point trustworthy?