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Question sets

  1. 1
    Started with introduction and then proceeded to demo of application.
    Times asked 2
    Official solution

    Simple30 second: naam, degree, project kya hai, stack (Flask + Jinja + SQLAlchemy + SQLite).

    Example

    Main Priya, IITM BS. MAD1 mein parking/ticket app — Flask backend, Jinja templates, session login, SQLite.
  2. 2
    What do you understand by web application development? What are the main aspects of it?
    Times asked 2
    Official solution

    SimpleMAD1 typical: Browser → Flask routes → validate/auth → SQLAlchemy → SQLite → Jinja response.

    Suggested flowRequest → Route → Auth check → DB → render_template / redirect

  3. 3
    What framework of Python do you use to render your view?
    Times asked 2
    Official solution

    SimpleStack bolo: Python, Flask, Jinja2, SQLAlchemy, SQLite, HTML/CSS/Bootstrap, maybe Chart.js.

  4. 4
    What do you understand by flask sqlalchemy?
    Times asked 1
    Official solution

    SimpleSQLAlchemy MAD1 ka common ORM. Flask-SQLAlchemy wrapper se db.Model, db.session.

    Example

    user = User(email='a@b.com')
    db.session.add(user)
    db.session.commit()
    users = User.query.filter_by(role='admin').all()
  5. 5
    What is celery?
    Times asked 6
    Official solution

    SimpleCelery background tasks (email, CSV, reports) async chalaata hai. Redis broker/queue + cache.

    User 'Export' click → Celery task queue → Redis message → worker CSV banaata hai → user baad mein download.
    Saath isliye: Celery ko broker chahiye, Redis tez in-memory. MAD2 topic zyada, MAD1 mein optional.
    Priority: task queues/routing. Caching: Redis mein key-value, DB hits kam.
    Pub/Sub: publisher channel pe message, subscribers sunte hain — Redis yeh bhi karta hai.

  1. 1
    what is redis and how did you implement it?
    Times asked 1
    Official solution

    SimpleRedis fridge pe sticky note hai — poori kitchen (database) kholne ki zarurat nahi.

    Redis in-memory key-value store hai. Data RAM mein rehta hai, isliye disk wale SQLite/Postgres se kai guna tez.

    MAD2 mein Redis do kaam karta hai:
    1) Cache — same venue/show/dashboard JSON baar-baar DB se mat nikaalo.
    2) Celery message broker — Flask task queue mein daalta hai, worker uthata hai.

    Source of truth database hi hai. Redis band ho to cache miss ho jaata hai aur Celery queue ruk sakti hai. Crash pe cache gayab ho sakta hai — isliye important data sirf Redis mein mat rakho.

    Example

    import redis
    r = redis.Redis(host='localhost', port=6379, db=0)
    r.set('venues', json.dumps(data), ex=30)
    print(r.get('venues'))

    Project example: GET /api/venues pehle Redis dekho. Miss pe SQLAlchemy query, phir SET with timeout. Celery worker Redis list se daily reminder uthata hai.

    Viva tipCache ke liye db=1, broker ke liye db=0 rakhna smart hai taaki keys mix na hon. Viva mein redis-cli ping → PONG dikhana strong hai.

  2. 2
    what are lifecycle hooks? explain a few of them
    Times asked 2
    Official solution

    SimpleLifecycle = component ki zindagi ke stages. API call tab jab DOM ready ho — mounted.

    created: instance bani, this data, DOM nahi. mounted/onMounted: page pe aa gaya — fetch, Chart.js, setInterval.
    updated: data change ke baad. unmounted: cleanup (clearInterval) warna memory leak.

    Dashboards onMounted isliye: canvas/API tab valid. created mein $el nahi.

    Composition: onMounted(() => {}) setup ke andar.

    Example

    export default {
      async mounted() {
        const r = await fetch('/api/venues')
        this.venues = await r.json()
      }
    }

    Project example: Venues.vue mounted fetch list. Clock component unmounted pe interval clear.

    Viva tipcreated: data setup, DOM nahi. mounted/onMounted: $el mil gaya — fetch yahi. Dashboards isliye onMounted use karti hain.

  3. 3
    explain celery w.r.t your code
    Times asked 2
    Official solution

    SimpleCode explain formula: input kya aaya → auth/validation → DB change → response/UI.

    Viva tipFunction signature + 3-4 important lines + edge case.

  4. 4
    how are you doing RBAC?
    Times asked 2
    Official solution

    SimpleRBAC = Role Based Access Control. Roles (admin/user) se permissions milti hain, har user pe alag list nahi.

    Example

    if current_user.role != 'admin':
        flash('Not allowed')
        return redirect(url_for('user.home'))
  5. 5
    what are props in vue?
    Times asked 1
    Official solution

    SimpleVue.js frontend framework — reactive UI components. MAD2 mein common, MAD1 optional.

    Component: reusable UI (Navbar.vue) + data + template.
    Props: parent → child data. Child → parent: $emit('update', val).
    Slots: parent child ke andar extra HTML daal sakta hai.
    Lifecycle: created (data setup), mounted (DOM ready — API call), updated, unmounted.
    v-model two-way bind. Vue Router SPA routes (routes.js). Vuex/Pinia global state; mutations sync change, actions async.
    Standalone component: khud ke saath compile, parent register kam.

  6. 6
    show a component and explain fetch request and the lifecycle hook used
    Times asked 1
    Official solution

    SimpleLifecycle = component ki zindagi ke stages. API call tab jab DOM ready ho — mounted.

    created: instance bani, this data, DOM nahi. mounted/onMounted: page pe aa gaya — fetch, Chart.js, setInterval.
    updated: data change ke baad. unmounted: cleanup (clearInterval) warna memory leak.

    Dashboards onMounted isliye: canvas/API tab valid. created mein $el nahi.

    Composition: onMounted(() => {}) setup ke andar.

    Example

    export default {
      async mounted() {
        const r = await fetch('/api/venues')
        this.venues = await r.json()
      }
    }

    Project example: Venues.vue mounted fetch list. Clock component unmounted pe interval clear.

    Viva tipcreated: data setup, DOM nahi. mounted/onMounted: $el mil gaya — fetch yahi. Dashboards isliye onMounted use karti hain.

  7. 7
    diff between caching and memoization
    Times asked 1
    Official solution

    SimpleMemoize args-aware. cached view/URL. Prefixes differ.

    Same Redis. Different key recipe.

    Redis in-memory key-value store hai — fridge pe sticky note, poori kitchen (SQL database) har baar mat kholo.

    MAD2 mein Redis do kaam: (1) cache — same venues/shows/dashboard JSON baar-baar DB se nahi (2) Celery broker — Flask task queue mein daalta hai, worker uthata hai.

    Flow: cache.get(key) → hit pe return, miss pe SQLAlchemy + SET with timeout. Admin write ke baad cache.delete, warna stale list.

    Source of truth database hi hai. Redis crash/band = cache miss (app chalni chahiye) + queue ruk sakti hai. Important bookings sirf Redis mein mat rakho.

    Alag: Redis ≠ Memcached (Celery broker nahi). Redis ≠ localStorage (woh browser). redis-cli ping → PONG viva proof.

    Project example: Two decorators two files explain.

  8. 8
    show where you have implemented caching and why we need it
    Times asked 1
    Official solution

    SimpleCache = pehli baar hisaab karke copy rakh lo, doosri baar copy dikha do.

    Baar-baar same expensive kaam (DB query, counting bookings) mat karo. Result Redis jaise store mein timeout ke saath rakh do.

    Cache hit: key mil gayi, DB skip. Cache miss: DB se lao, SET karo, return karo.

    Tradeoff: speed vs stale data. Admin naya venue add kare aur cache 50s ka ho to user purani list dekh sakta hai — isliye write pe invalidation zaroori hai.

    Browser cache, Flask-Caching, Redis alag layers hain. MAD2 examiner Redis + @cache.cached code dekhta hai.

    Example

    @cache.cached(timeout=50, query_string=True)
    @app.route('/api/shows')
    def shows():
        return jsonify([s.serialize() for s in Show.query.all()])

    Project example: Admin dashboard counts / venues list cache. Create/update/delete ke baad cache.delete('venues').

    Viva tipprint('DB queried') function ke andar laga ke miss/hit demo karo — hit pe print nahi chalega.

  1. 1
    Demo of your application
    Times asked 2
    Official solution

    SimpleDemo script pehle se practice: 5–7 min, Admin + User roles, saare mandatory features.

    Suggested flow1) Register/login user
    2) Admin login — CRUD
    3) Approval/blacklist
    4) Booking/apply + edge case
    5) Search
    6) Logout

    Viva tipBolte-bolte dikhao. Code tab kholna jab poochhein.

  2. 2
    Checked if the modification made to show details is reflected in the user page.
    Times asked 2
    Official solution

    SimpleDemo script pehle se practice: 5–7 min, Admin + User roles, saare mandatory features.

    Suggested flow1) Register/login user
    2) Admin login — CRUD
    3) Approval/blacklist
    4) Booking/apply + edge case
    5) Search
    6) Logout

    Viva tipBolte-bolte dikhao. Code tab kholna jab poochhein.

  3. 3
    What is lazy loading?
    Times asked 3
    Official solution

    Simplelazy loading related objects tab load karta hai jab attribute access karte ho, pehle nahi.

    user = User.query.get(1)  # posts query nahi

    user.posts # ab query

    lazy=True / 'select' default. lazy='joined' eager join. lazy='dynamic' query object.
    uselist=False One-to-One (single object, list nahi). Hataoge to list mil sakti hai.
    Frontend lazy loading images alag cheez hai (viewport mein aaye tab load).

  4. 4
    SPA
    Times asked 1
    Official solution

    SimpleMAD1 typical: Browser → Flask routes → validate/auth → SQLAlchemy → SQLite → Jinja response.

    Suggested flowRequest → Route → Auth check → DB → render_template / redirect

  5. 5
    POST and GET
    Times asked 2
    Official solution

    SimpleGET data read/show karta hai (idempotent). POST create/submit karta hai (form).

    Example

    @app.route('/login', methods=['GET', 'POST'])
    def login():
        if request.method == 'POST':
            # validate + session
            ...
        return render_template('login.html')
  1. 1
    Difference between authentication and authorisation
    Times asked 4
    Official solution

    SimpleAuthentication: tu kaun hai? (login). Authorization: tujhe permission hai? (role check).

    Example

    # auth
    if check_password_hash(user.password, pwd):
        session['user_id'] = user.id
    
    # authz
    if user.role != 'admin':
        abort(403)
  2. 2
    how have i implemented RBAC for admin
    Times asked 1
    Official solution

    SimpleRBAC = Role Based Access Control. Roles (admin/user) se permissions milti hain, har user pe alag list nahi.

    Example

    if current_user.role != 'admin':
        flash('Not allowed')
        return redirect(url_for('user.home'))
  1. 1
    How you are tokens ,,by which framework
    Times asked 2
    Official solution

    SimpleCode explain formula: input kya aaya → auth/validation → DB change → response/UI.

    Viva tipFunction signature + 3-4 important lines + edge case.

  1. 1
    (1) Asked to show working function of app
    Times asked 2
    Official solution

    SimpleDemo script pehle se practice: 5–7 min, Admin + User roles, saare mandatory features.

    Suggested flow1) Register/login user
    2) Admin login — CRUD
    3) Approval/blacklist
    4) Booking/apply + edge case
    5) Search
    6) Logout

    Viva tipBolte-bolte dikhao. Code tab kholna jab poochhein.

  2. 2
    (2) venue and show capacity constraint (Eg. 100 seats in venue then for show inside that venue we cant allot 120 seats)
    Times asked 2
    Official solution

    SimpleViva wrap-up hai. Short thanks + confirm submission ZIP latest hai.

  3. 3
    (4) SPA
    Times asked 2
    Official solution

    SimpleMAD1 typical: Browser → Flask routes → validate/auth → SQLAlchemy → SQLite → Jinja response.

    Suggested flowRequest → Route → Auth check → DB → render_template / redirect

  4. 4
    (5) single page and multipage difference
    Times asked 2
    Official solution

    SimpleMAD1 typical: Browser → Flask routes → validate/auth → SQLAlchemy → SQLite → Jinja response.

    Suggested flowRequest → Route → Auth check → DB → render_template / redirect

  5. 5
    (6) Explain edit show code from from frontend to backend
    Times asked 1
    Official solution

    SimpleCode dikhao to pehle related file: models → route → template. Flow explain karte hue lines padho.

  6. 6
    (7) Explain models
    Times asked 1
    Official solution

    Simplemodels.py = har table ki class: columns, PK/FK, relationships. Yeh Model layer hai.

    Suggested flow1) Classes list karo
    2) Har table ka kaam 1 line
    3) Relationships (1-M / M-M)
    4) Constraints (unique, nullable)

    Example

    class Lot(db.Model):
        id = db.Column(db.Integer, primary_key=True)
        name = db.Column(db.String(80), nullable=False)
        spots = db.relationship('Spot', backref='lot', lazy=True)
  7. 7
    (8) Implement constraint on password length (Frontend)
    Times asked 2
    Official solution

    SimpleMAD1 frontend usually Jinja templates + HTML/CSS/Bootstrap (+ thoda JS). MAD2 pe Vue ho to clearly bolo.

  8. 8
    (10) Can we use POST instead of PUT
    Times asked 2
    Official solution

    SimplePOST naya janam (har baar naya id). PUT poori photo replace. PATCH sticker chipkao.

    POST create, not idempotent. PUT full update, idempotent. PATCH partial.

    POST ki jagah PUT se REST semantics toot. GET typically no body.

    CRUD map: POST create, GET read, PUT/PATCH update, DELETE delete.

    Pehle 1-line definition, phir related MAD2 layer (Vue SFC / Flask route / models.py / tasks.py / Redis).

    4-line formula: input kahan se aaya, auth/validation kaunsa, DB ya cache ya Celery, kya return.

    Related mix mat karo — cache ≠ Celery, authentication ≠ authorization, v-if ≠ v-show, Beat ≠ Worker. Follow-up ke liye ek difference ready rakho.

    Example

    POST /api/venues
    PUT  /api/venues/1   {all fields}
    PATCH /api/venues/1 {only name}

    Project example: POST /api/venues create. PUT /venues/1 saari fields. PATCH sirf name.

  1. 1
    Introduction
    Times asked 5
    Official solution

    Simple30 second: naam, degree, project kya hai, stack (Flask + Jinja + SQLAlchemy + SQLite).

    Example

    Main Priya, IITM BS. MAD1 mein parking/ticket app — Flask backend, Jinja templates, session login, SQLite.
  2. 2
    Demonstration of the application
    Times asked 2
    Official solution

    SimpleDemo script pehle se practice: 5–7 min, Admin + User roles, saare mandatory features.

    Suggested flow1) Register/login user
    2) Admin login — CRUD
    3) Approval/blacklist
    4) Booking/apply + edge case
    5) Search
    6) Logout

    Viva tipBolte-bolte dikhao. Code tab kholna jab poochhein.

  3. 3
    Then he saw the entire codebase
    Times asked 2
    Official solution

    SimplePehle 1-line definition, phir apne MAD1 project mein file dikhao, phir chhota example.

    Suggested flow1) Concept kya hai?
    2) Mere code mein kahan?
    3) Example / demo
    4) Edge case

    Example

    # related file: models.py / routes / template
    # formula: request → check/auth → DB → render/redirect

    Viva tipExact line yaad nahi to honestly related part dikhao. Bluff mat karo.

  4. 4
    What is Vue, why have you used vue?
    Times asked 2
    Official solution

    SimpleVue = UI ka smart assistant. Data badlo, screen khud update. MAD1 Jinja har click pe naya HTML.

    Progressive frontend framework. Components, reactivity, directives.

    MAD2 SPA: ek index.html, Vue Router pages, Flask sirf JSON.

    Fayde: easy, SFC, docs. Vs React: templates HTML-like, course sikhata hai. Vs plain JS: baar-baar DOM mat chhedo.

    Example

    <!-- HelloWorld.vue -->
    <template>
      <h1>{{ msg }}</h1>
    </template>
    <script>
    export default { data() { return { msg: 'Hello' } } }
    </script>

    Project example: Navbar.vue + views (Login, Dashboard). data() / setup() reactive. fetch APIs.

    Viva tipFayde: easy, SFC, reactivity. Vs React: chhota learning curve. Vs plain JS: UI state auto-update.

  5. 5
    Which part did you find hard to code, frontend or backend
    Times asked 2
    Official solution

    SimpleMAD1 frontend usually Jinja templates + HTML/CSS/Bootstrap (+ thoda JS). MAD2 pe Vue ho to clearly bolo.

  6. 6
    What are lifecycle hooks
    Times asked 2
    Official solution

    SimpleVue.js frontend framework — reactive UI components. MAD2 mein common, MAD1 optional.

    Component: reusable UI (Navbar.vue) + data + template.
    Props: parent → child data. Child → parent: $emit('update', val).
    Slots: parent child ke andar extra HTML daal sakta hai.
    Lifecycle: created (data setup), mounted (DOM ready — API call), updated, unmounted.
    v-model two-way bind. Vue Router SPA routes (routes.js). Vuex/Pinia global state; mutations sync change, actions async.
    Standalone component: khud ke saath compile, parent register kam.

  7. 7
    Asked what each decorator does (app.route, cache.memoize, celery.task)
    Times asked 2
    Official solution

    Simplelogin_required jaisa decorator protected routes pe: session nahi to login redirect.

    Example

    def login_required(fn):
        @wraps(fn)
        def wrapper(*a, **k):
            if 'user_id' not in session:
                return redirect(url_for('auth.login'))
            return fn(*a, **k)
        return wrapper
  8. 8
    Asked to change the style of buttons at frontend
    Times asked 2
    Official solution

    SimpleLive UI change: relevant CSS/HTML template kholo — color, margin, flex, bootstrap class. Save + hard refresh.

    Example

    /* button red */
    .btn-primary { background: red; }
    
    /* center navbar item */
    .navbar { justify-content: center; }

    Viva tipDevTools se pehle try, phir file mein permanent change.

  9. 9
    What other features can you add to the webapp?
    Times asked 2
    Official solution

    SimplePehle 1-line definition, phir apne MAD1 project mein file dikhao, phir chhota example.

    Suggested flow1) Concept kya hai?
    2) Mere code mein kahan?
    3) Example / demo
    4) Edge case

    Example

    # related file: models.py / routes / template
    # formula: request → check/auth → DB → render/redirect

    Viva tipExact line yaad nahi to honestly related part dikhao. Bluff mat karo.

  10. 10
    What is celery and how is it used to create scheduled jobs?
    Times asked 1
    Official solution

    SimpleLive jobs: Redis, worker, beat, crontab abhi, logs + email/CSV.

    Scheduled vs user-triggered dono dikhao. Missing feature honestly.

    Examiner 2 cheezein: simple desi line + tumhare project ki exact file.

    Pehle ID, GitHub, portal ZIP. Phir run: Redis + Flask + worker + beat + Vue. Feature demo: login, RBAC, cache hit/miss, Celery mail, search.

    Line pe ungli: input kahan, kaunsa check, query/cache/task, JSON/UI. Copilot band. Jo nahi kiya honestly bolo + kaise add karte.

    Suggested flow1) redis
    2) worker
    3) beat
    4) crontab now
    5) logs + MailHog

    Example

    CELERY_BEAT_SCHEDULE = {
      'daily-reminder': {
        'task': 'jobs.daily_reminder',
        'schedule': crontab(hour=18, minute=0),
      },
    }

    Project example: Change schedule current time. MailHog. Export button 202.

  1. 1
    Csrf
    Times asked 2
    Official solution

    SimpleCSRF = Cross-Site Request Forgery — logged-in user ke browser se attacker site hidden form submit karwati hai.

    FixCSRF token hidden field, server verify. Flask-WTF: {{ form.hidden_tag() }}

    SameSite cookies bhi help. GET pe destructive action mat rakho.

  2. 2
    Cors
    Times asked 2
    Official solution

    SimpleDifferent origin Vue vs Flask — browser CORS check. Server Allow-Origin.

    Failed = frontend error even if curl works. Examiner curl vs browser.

    HTTP verbs + status REST ki zabaan. GET read, POST create, PUT replace, PATCH partial, DELETE remove. GET typically no body.

    Status: 200 OK, 201 created, 202 accepted (Celery task), 400 bad input, 401 no/bad token, 403 role nahi, 404 missing, 409 conflict (double book), 500 server.

    AJAX/fetch page reload nahi. SPA poori isi pe. Postman se bina Vue ke API prove karo — examiner pasand.

    Example

    from flask_cors import CORS
    CORS(app, resources={r'/api/*': {'origins': 'http://localhost:8080'}})

    Project example: Flask-CORS localhost:8080.

  3. 3
    He told me to move the button in nav bar to the right.
    Times asked 2
    Official solution

    SimpleLive UI change: relevant CSS/HTML template kholo — color, margin, flex, bootstrap class. Save + hard refresh.

    Example

    /* button red */
    .btn-primary { background: red; }
    
    /* center navbar item */
    .navbar { justify-content: center; }

    Viva tipDevTools se pehle try, phir file mein permanent change.

  4. 4
    Mutations and actions
    Times asked 2
    Official solution

    SimpleMutations sync diary entry. Actions async kaam phir diary.

    Direct state mutate action se Vuex 4 discouraged. Devtools time-travel mutations.

    Purpose of Actions: API, phir commit. Purpose of Mutations: state change one place.

    Pehle 1-line definition, phir related MAD2 layer (Vue SFC / Flask route / models.py / tasks.py / Redis).

    4-line formula: input kahan se aaya, auth/validation kaunsa, DB ya cache ya Celery, kya return.

    Related mix mat karo — cache ≠ Celery, authentication ≠ authorization, v-if ≠ v-show, Beat ≠ Worker. Follow-up ke liye ek difference ready rakho.

    Project example: action fetchVenues → commit setVenues. Mutation sirf array replace.

  5. 5
    Lifecycle hooks
    Times asked 6
    Official solution

    SimpleLifecycle = component ki zindagi ke stages. API call tab jab DOM ready ho — mounted.

    created: instance bani, this data, DOM nahi. mounted/onMounted: page pe aa gaya — fetch, Chart.js, setInterval.
    updated: data change ke baad. unmounted: cleanup (clearInterval) warna memory leak.

    Dashboards onMounted isliye: canvas/API tab valid. created mein $el nahi.

    Composition: onMounted(() => {}) setup ke andar.

    Example

    export default {
      async mounted() {
        const r = await fetch('/api/venues')
        this.venues = await r.json()
      }
    }

    Project example: Venues.vue mounted fetch list. Clock component unmounted pe interval clear.

    Viva tipcreated: data setup, DOM nahi. mounted/onMounted: $el mil gaya — fetch yahi. Dashboards isliye onMounted use karti hain.

  6. 6
    Difference between security and privacy
    Times asked 2
    Official solution

    SimplePrivacy personal data minimize. Security attacks rokna CIA. Overlap not same.

    GDPR vs firewall example.

    Browser + API ke beech extra darwaze: CORS origin allow, HTTPS encrypt transit, CSRF cookie-auto-send attack, XSS HTML inject, SQL injection raw query.

    MAD2 SPA: Vue :8080 Flask :5000 → Flask-CORS. JWT localStorage XSS se chori ho sakta — v-html user input pe avoid. Password Network tab localhost pe dikhega; prod HTTPS, response mein password echo nahi.

    401 unauthenticated, 403 unauthorized, 400 validation. Hash one-way — SHA decrypt nahi hota. Secret key .env, GitHub pe nahi.

    Project example: Don't return other users' emails to normal user API.

  7. 7
    Delete on cascade
    Times asked 2
    Official solution

    SimpleCascade parent delete pe children pe kya ho: delete-orphan related rows hata deta hai.

    Example

    db.relationship('Spot', cascade='all, delete-orphan')

    Viva tipParking lot delete → uske spots/bookings policy clear bolo.

  8. 8
    Data type error in sqlalchemy
    Times asked 2
    Official solution

    SimpleSQLAlchemy MAD1 ka common ORM. Flask-SQLAlchemy wrapper se db.Model, db.session.

    Example

    user = User(email='a@b.com')
    db.session.add(user)
    db.session.commit()
    users = User.query.filter_by(role='admin').all()
  9. 9
    Components in vue.js
    Times asked 2
    Official solution

    SimpleVue = UI ka smart assistant. Data badlo, screen khud update. MAD1 Jinja har click pe naya HTML.

    Progressive frontend framework. Components, reactivity, directives.

    MAD2 SPA: ek index.html, Vue Router pages, Flask sirf JSON.

    Fayde: easy, SFC, docs. Vs React: templates HTML-like, course sikhata hai. Vs plain JS: baar-baar DOM mat chhedo.

    Example

    <!-- HelloWorld.vue -->
    <template>
      <h1>{{ msg }}</h1>
    </template>
    <script>
    export default { data() { return { msg: 'Hello' } } }
    </script>

    Project example: Navbar.vue + views (Login, Dashboard). data() / setup() reactive. fetch APIs.

    Viva tipFayde: easy, SFC, reactivity. Vs React: chhota learning curve. Vs plain JS: UI state auto-update.

  10. 10
    Redis
    Times asked 6
    Official solution

    SimpleRedis fridge pe sticky note hai — poori kitchen (database) kholne ki zarurat nahi.

    Redis in-memory key-value store hai. Data RAM mein rehta hai, isliye disk wale SQLite/Postgres se kai guna tez.

    MAD2 mein Redis do kaam karta hai:
    1) Cache — same venue/show/dashboard JSON baar-baar DB se mat nikaalo.
    2) Celery message broker — Flask task queue mein daalta hai, worker uthata hai.

    Source of truth database hi hai. Redis band ho to cache miss ho jaata hai aur Celery queue ruk sakti hai. Crash pe cache gayab ho sakta hai — isliye important data sirf Redis mein mat rakho.

    Example

    import redis
    r = redis.Redis(host='localhost', port=6379, db=0)
    r.set('venues', json.dumps(data), ex=30)
    print(r.get('venues'))

    Project example: GET /api/venues pehle Redis dekho. Miss pe SQLAlchemy query, phir SET with timeout. Celery worker Redis list se daily reminder uthata hai.

    Viva tipCache ke liye db=1, broker ke liye db=0 rakhna smart hai taaki keys mix na hon. Viva mein redis-cli ping → PONG dikhana strong hai.

  11. 11
    Celery
    Times asked 9
    Official solution

    SimpleCelery = background naukri. HTTP request ko 10 second email bhejne ke liye mat rokna.

    Distributed task queue: aap function ko abhi nahi, worker process mein later/retry/schedule pe chalaate ho.

    MAD2 typical jobs: daily reminder mail, monthly HTML report, user-triggered CSV export.

    Web request 200ms hona chahiye. 10,000 emails request thread mein = timeout. Worker alag CPU pe kaam kare.

    Redis broker chahiye. Beat alag process schedule ke liye.

    Example

    @celery.task
    def daily_reminder():
        for u in User.query.filter_by(active=True):
            send_mail(u.email, 'Book something today!')

    Project example: User Export click → 202 Accepted. Worker CSV + email. Daily 6pm Beat reminder.

    Viva tipWorker + Redis bina Beat ke user-triggered chalega. Scheduled jobs ke liye Beat bhi chahiye.

  12. 12
    Publish and subscribe
    Times asked 2
    Official solution

    SimpleViva wrap-up hai. Short thanks + confirm submission ZIP latest hai.

  13. 13
    Scaling in application
    Times asked 2
    Official solution

    SimpleLoad badhe to handle: scale up/out, cache, async, DB tune.

    SQL scale: indexes, pool, replicas, partition, cache hot queries.

    Pehle 1-line definition, phir related MAD2 layer (Vue SFC / Flask route / models.py / tasks.py / Redis).

    4-line formula: input kahan se aaya, auth/validation kaunsa, DB ya cache ya Celery, kya return.

    Related mix mat karo — cache ≠ Celery, authentication ≠ authorization, v-if ≠ v-show, Beat ≠ Worker. Follow-up ke liye ek difference ready rakho.

    Project example: If 10k: URI postgres, gunicorn, cache, celery concurrency.

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