Interview Q&A

Answer: ccess them in workflows: env: WS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}

What interviewers expect

• A clear definition tied to Version Control in Git & GitHub projects
• Trade-offs (performance, maintainability, security, cost)
• When you would and would not use it in production

Real-world example

In a production Git & GitHub application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.

How to explain in the interview

1. Define the concept in one or two sentences.
2. Context — where it fits in Git & GitHub architecture.
3. Example — a specific project, bug, or performance win.
4. Trade-off — what you gain vs what you sacrifice.

Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.

Answer: <<<<<<< HEAD your code ======= incoming code >>>>>>> branch

What interviewers expect

• A clear definition tied to Version Control in Git & GitHub projects
• Trade-offs (performance, maintainability, security, cost)
• When you would and would not use it in production

Real-world example

In a production Git & GitHub application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.

How to explain in the interview

1. Define the concept in one or two sentences.
2. Context — where it fits in Git & GitHub architecture.
3. Example — a specific project, bug, or performance win.
4. Trade-off — what you gain vs what you sacrifice.

Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.

My preferred strategy depends on the project type and team size:

• For large enterprise projects with planned releases → I prefer Git Flow.
• Branches: main, develop, feature/*, release/*, hotfix/*
• Benefits: Organized release management, clear isolation of features and

fixes.

• For agile teams or startups deploying multiple times a day → I prefer Trunk-Based

Development.

• Developers work on short-lived feature branches and merge into main

frequently (often daily).

• CI/CD pipelines ensure code is always deployable.

Real-world example:

t my last company, we used Trunk-Based Development for a SaaS platform — it reduced

merge conflicts and allowed fast continuous deployment.

source code during software development.

What interviewers expect

• A clear definition tied to Version Control in Git & GitHub projects
• Trade-offs (performance, maintainability, security, cost)
• When you would and would not use it in production

Real-world example

In a production Git & GitHub application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.

How to explain in the interview

1. Define the concept in one or two sentences.
2. Context — where it fits in Git & GitHub architecture.
3. Example — a specific project, bug, or performance win.
4. Trade-off — what you gain vs what you sacrifice.

Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.

Answer: Store tokens (like AWS_ACCESS_KEY, DOCKER_TOKEN) in → Settings > Secrets and variables > Actions Access them in workflows: env: AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}

What interviewers expect

• A clear definition tied to Version Control in Git & GitHub projects
• Trade-offs (performance, maintainability, security, cost)
• When you would and would not use it in production

Real-world example

In a production Git & GitHub application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.

How to explain in the interview

1. Define the concept in one or two sentences.
2. Context — where it fits in Git & GitHub architecture.
3. Example — a specific project, bug, or performance win.
4. Trade-off — what you gain vs what you sacrifice.

Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.

Answer: git config --global user.signingkey <key-id> git config --global commit.gpgsign true

What interviewers expect

• A clear definition tied to Version Control in Git & GitHub projects
• Trade-offs (performance, maintainability, security, cost)
• When you would and would not use it in production

Real-world example

In a production Git & GitHub application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.

How to explain in the interview

1. Define the concept in one or two sentences.
2. Context — where it fits in Git & GitHub architecture.
3. Example — a specific project, bug, or performance win.
4. Trade-off — what you gain vs what you sacrifice.

Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.

Integration means connecting your Git repository to your CI/CD system so every

push, pull request, or tag triggers an automated build, test, and deploy pipeline.

✅ Jenkins Integration

• Install the Git plugin in Jenkins.

Create a new pipeline job and link it to your Git repository:

pipeline {

gent any

stages {

stage('Checkout') {

steps {

git branch: 'main', url:

}
}

stage('Build') {

steps {

sh 'npm install'

sh 'npm test'

}
}
}
}

• ● Jenkins polls Git or listens for webhooks to trigger builds automatically.

✅ GitLab CI/CD

GitLab CI is built-in — simply create .gitlab-ci.yml:

stages:

• test
• deploy

test:

script:

• npm install
• npm test

deploy:

script:

• ./deploy.sh

only:

• main

Every push triggers this pipeline automatically.

✅ GitHub Actions

GitHub has its own YAML-based workflows:

name: Node CI

on: [push, pull_request]

jobs:

build:

runs-on: ubuntu-latest

steps:

• uses: actions/checkout@v4
• run: npm ci
• run: npm test

It runs directly in GitHub without needing extra setup.

Real-world example:

Your team pushes code to GitHub → GitHub Actions automatically runs tests →

Jenkins (or GitLab CI) deploys to a staging environment → Approval required for

production deploy.

git cherry-pick <commit-hash>

What interviewers expect

• A clear definition tied to Version Control in Git & GitHub projects
• Trade-offs (performance, maintainability, security, cost)
• When you would and would not use it in production

Real-world example

In a production Git & GitHub application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.

How to explain in the interview

1. Define the concept in one or two sentences.
2. Context — where it fits in Git & GitHub architecture.
3. Example — a specific project, bug, or performance win.
4. Trade-off — what you gain vs what you sacrifice.

Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.

git switch -c hotfix/save-work

What interviewers expect

• A clear definition tied to Version Control in Git & GitHub projects
• Trade-offs (performance, maintainability, security, cost)
• When you would and would not use it in production

Real-world example

In a production Git & GitHub application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.

How to explain in the interview

1. Define the concept in one or two sentences.
2. Context — where it fits in Git & GitHub architecture.
3. Example — a specific project, bug, or performance win.
4. Trade-off — what you gain vs what you sacrifice.

Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.

git checkout -b feature/login abc1234

What interviewers expect

• A clear definition tied to Version Control in Git & GitHub projects
• Trade-offs (performance, maintainability, security, cost)
• When you would and would not use it in production

Real-world example

In a production Git & GitHub application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.

How to explain in the interview

1. Define the concept in one or two sentences.
2. Context — where it fits in Git & GitHub architecture.
3. Example — a specific project, bug, or performance win.
4. Trade-off — what you gain vs what you sacrifice.

Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.

Answer: dashboard). → This prevents misuse. Remove the secret from code: git rm --cached path/to/file git commit -m "Remove sensitive file"

What interviewers expect

• A clear definition tied to Version Control in Git & GitHub projects
• Trade-offs (performance, maintainability, security, cost)
• When you would and would not use it in production

Real-world example

In a production Git & GitHub application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.

How to explain in the interview

1. Define the concept in one or two sentences.
2. Context — where it fits in Git & GitHub architecture.
3. Example — a specific project, bug, or performance win.
4. Trade-off — what you gain vs what you sacrifice.

Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.

Answer: Accidentally pushing secrets (API keys, passwords, tokens) is serious — even if you delete them, they may still exist in commit history. Steps to fix it:

What interviewers expect

• A clear definition tied to Version Control in Git & GitHub projects
• Trade-offs (performance, maintainability, security, cost)
• When you would and would not use it in production

Real-world example

In a production Git & GitHub application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.

How to explain in the interview

1. Define the concept in one or two sentences.
2. Context — where it fits in Git & GitHub architecture.
3. Example — a specific project, bug, or performance win.
4. Trade-off — what you gain vs what you sacrifice.

Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.

git merge origin/main

What interviewers expect

• A clear definition tied to Version Control in Git & GitHub projects
• Trade-offs (performance, maintainability, security, cost)
• When you would and would not use it in production

Real-world example

In a production Git & GitHub application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.

How to explain in the interview

1. Define the concept in one or two sentences.
2. Context — where it fits in Git & GitHub architecture.
3. Example — a specific project, bug, or performance win.
4. Trade-off — what you gain vs what you sacrifice.

Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.

After initializing a Git repo locally (git init), you can connect it to a remote repository

(like one on GitHub) using:

git remote add origin

Then push your code:

git push -u origin main

Explanation:

• origin is just a nickname for the remote URL.
• The -u flag links your local branch with the remote one so future pushes are easier

(git push alone works after that).

Real-world example:

You create a local portfolio website and later decide to host it on GitHub. You connect your

local repo to the remote one using git remote add origin so both stay in sync.

Answer: Mark the conflicting sections in your file: <<<<<<< HEAD your current branch code ======= incoming branch code >>>>>>> feature/new-ui

What interviewers expect

• A clear definition tied to Version Control in Git & GitHub projects
• Trade-offs (performance, maintainability, security, cost)
• When you would and would not use it in production

Real-world example

In a production Git & GitHub application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.

How to explain in the interview

1. Define the concept in one or two sentences.
2. Context — where it fits in Git & GitHub architecture.
3. Example — a specific project, bug, or performance win.
4. Trade-off — what you gain vs what you sacrifice.

Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.

A Git tag marks specific points in a repository’s history — usually to label release versions

(like v1.0, v2.1, etc.). It’s like a snapshot that says, “this commit is stable and ready to

release.”

Types of tags:

• Lightweight tag: just a name for a commit.
• Annotated tag: includes metadata like the tagger’s name, date, and message.

Commands:

git tag -a v1.0 -m "Version 1.0 release"

git push origin v1.0

Real-world example:

fter testing your project, you tag the commit representing your first release with v1.0. This

helps other developers or CI/CD pipelines identify which version is live.

Answer: <<<<<<< HEAD current branch code ======= incoming branch code >>>>>>> feature/contact-form

What interviewers expect

• A clear definition tied to Version Control in Git & GitHub projects
• Trade-offs (performance, maintainability, security, cost)
• When you would and would not use it in production

Real-world example

In a production Git & GitHub application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.

How to explain in the interview

1. Define the concept in one or two sentences.
2. Context — where it fits in Git & GitHub architecture.
3. Example — a specific project, bug, or performance win.
4. Trade-off — what you gain vs what you sacrifice.

Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.

A branch in Git is like a separate line of development — a parallel universe for your code. It

llows you to work on new features, bug fixes, or experiments without affecting the main

codebase (usually called the main or master branch).

Why branches are useful:

They make collaboration easier by keeping each developer’s work isolated until it’s ready to

be merged back.

Real-world example:

Imagine your company website is live, but you need to add a “dark mode” feature. Instead

of editing the main code directly (which might break the live site), you create a new branch

called feature/dark-mode to work independently. Once it’s done and tested, you merge it

back into main.

Git is a distributed version control system (VCS) that allows multiple developers to work on

project without overwriting each other's work. It's designed to be fast, flexible, and

scalable, allowing developers to track changes in code and collaborate with ease.

In contrast, SVN (Subversion) is a centralized version control system. This means that SVN

has one central repository, and developers check out code to work locally. Git, on the other

hand, allows every developer to have their own full local repository, including the project’s

history. This makes Git faster and more reliable, especially in distributed teams.

Real-World Example:

If you were working on a website project with a team, using Git allows each developer to

clone the repository, make changes locally, and push their changes without disrupting others.

In SVN, the code is pulled from the central server, and only one developer can commit

changes at a time.

Answer: A distributed version control system (DVCS) for tracking changes in source code during software development.

What interviewers expect

• A clear definition tied to Version Control in Git & GitHub projects
• Trade-offs (performance, maintainability, security, cost)
• When you would and would not use it in production

Real-world example

In a production Git & GitHub application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.

How to explain in the interview

1. Define the concept in one or two sentences.
2. Context — where it fits in Git & GitHub architecture.
3. Example — a specific project, bug, or performance win.
4. Trade-off — what you gain vs what you sacrifice.

Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.

git checkout wrong-branch git reset --hard HEAD~2

What interviewers expect

• A clear definition tied to Version Control in Git & GitHub projects
• Trade-offs (performance, maintainability, security, cost)
• When you would and would not use it in production

Real-world example

In a production Git & GitHub application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.

How to explain in the interview

1. Define the concept in one or two sentences.
2. Context — where it fits in Git & GitHub architecture.
3. Example — a specific project, bug, or performance win.
4. Trade-off — what you gain vs what you sacrifice.

Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.

• origin – The main remote repository you cloned or own.
• upstream – Usually refers to the original repository that your fork came from.

Example:

If you fork a popular open-source project:

• Your fork on GitHub = origin
• The original repo (the one you forked from) = upstream

Commands to set both:

git remote add origin

git remote add upstream

Why it matters:

This setup lets you pull new changes from the main project (upstream) while pushing your

changes to your fork (origin).

Git is the tool used to track changes in your code locally (on your computer), whereas

GitHub is a platform that hosts Git repositories online, enabling collaboration and sharing.

GitHub allows teams to work on Git-based projects in a central location, review code, and

manage issues and pull requests.

Real-World Example:

You use Git to make changes to your website’s code locally. Once you're happy with your

changes, you push them to GitHub so your team can see and review the updates. GitHub is

essentially a cloud service that works on top of Git.

Answer: including its entire history, allowing for offline work and decentralized collaboration.

What interviewers expect

• A clear definition tied to Version Control in Git & GitHub projects
• Trade-offs (performance, maintainability, security, cost)
• When you would and would not use it in production

Real-world example

In a production Git & GitHub application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.

How to explain in the interview

1. Define the concept in one or two sentences.
2. Context — where it fits in Git & GitHub architecture.
3. Example — a specific project, bug, or performance win.
4. Trade-off — what you gain vs what you sacrifice.

Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.

Answer: GitHub Actions tokens (GITHUB_TOKEN) should have minimal scopes: permissions: contents: read deployments: write packages: read

What interviewers expect

• A clear definition tied to Version Control in Git & GitHub projects
• Trade-offs (performance, maintainability, security, cost)
• When you would and would not use it in production

Real-world example

In a production Git & GitHub application, teams apply this when handling user-facing features or integration boundaries. For example, you might use it during a sprint where reliability and observability matter—logging metrics, validating edge cases, and documenting the decision in an ADR so future developers understand why the approach was chosen.

How to explain in the interview

1. Define the concept in one or two sentences.
2. Context — where it fits in Git & GitHub architecture.
3. Example — a specific project, bug, or performance win.
4. Trade-off — what you gain vs what you sacrifice.

Tip: Practice aloud on Toolliyo mock interview or the Interview Q&A section before your real interview.