Podcast2026
بِسْمِ اللَّهِ الرَّحْمَٰنِ الرَّحِيمِ
Cambridge
Computer Science
you can run.
Write pseudocode, see it run, then try real exam questions marked for you.
Just landed · updated 8 Nov 2026
What's new on CS with ZAK
AskZ now reads your photos and papers, the real past paper marks itself end to end, and every page has its own help. Here's what changed — on the website and in the ZAPP app.
New20 Oct 2026
Your study route: the whole syllabus, one section at a time
Pick your level and follow every syllabus section in order: read the notes, watch a lecture, pass a 5-question check, then flashcards and real past-paper questions. A chapter test closes each topic, and a 10-minute check first tells you where to begin.
- Continue on the home page takes you to your next section
- A pace that finishes a week before your paper, with dates for your calendar
- Checks are advice: re-read, try a fresh 5, or skip and come back
- O Level / IGCSE, AS, A2 and Full A Level
Open the study route
New17 Oct 2026
ZAK's books: prices, sets and ordering in a few taps
Every book, workbook and ebook now shows its price, and each level has a set of two books and two workbooks that costs less than its parts. Add it to your basket and the order goes straight to the books desk on WhatsApp.
- Sets for O Level (current and new syllabus), AS, A2 and Full A Level
- Black and white, full colour or ebook
- Free delivery on every printed set in Pakistan
- Printed fresh for your order, delivered in 7–10 working days
Choose your set
Also new · 4
Improved8 Nov 2026Classroom: Teach or Study, two plain doorsSigned in, the Classroom page now starts with two doors: Teach for the classes you teach and Study for the classes you are a student in, each saying what is waiting inside. The demo class sits apart, named as a made-up class. Teach has a class rail on the left, five tab groups per class and a three-step card for your first class.Open Classroom For teachers8 Nov 2026Classroom: Service keys, your own accounts for live classesEvery teacher connects their own accounts under Service keys: the built-in room on your Cloudflare RealtimeKit account, Zoom, Google Meet and Google Classroom, and Microsoft Teams, each with numbered steps. Choose the AskZ engine or your own AI key for marking.Open Service keys For teachers7 Nov 2026Classroom: the report, class and student PDFs, bulk actionsEach piece of work has a report: facility and discrimination for every question, topics, the weakest syllabus bullets and a quiz's distractor table. The gradebook gives a class report PDF and one per student from released marks. Tick rows on the desk to release, hold, return, extend or excuse many students at once.Open your classes For teachers7 Nov 2026Classroom: start free, take a trial term, or look around the demoAn approved teacher can now start Classroom alone: Start free gives one class with every feature, a trial term gives sixty days for more students, and the demo class is a finished class to press anything in. A licence for more is arranged through the enquiry form.Open your console
Three ways in
Learn it. Practise it. Ask about it.
Everything on the site sits behind one of these. Start with whichever you need today.
Learn
Read, watch, understand
30 topics in syllabus order, each with Smart Notes, ZAK's lectures, infographics and key terms.
- 30
- topics
- 588
- lectures
Practise
Real questions, marked for you
Every Cambridge question since 2015 by topic, with the mark scheme and the examiner's comment — plus quick rounds.
- 3,450
- exam questions
- 1,613
- quiz questions
Ask
Stuck? Ask, any time
AskZ knows the syllabus and this whole site. It explains, marks your answer and reads a photo of your question.
- 24/7
- day and night
- Free
- always
3,450
real exam questions, by topic
1,613
auto-marked quiz questions
30
topics, each with Smart Notes + assignments
68
exam-ready infographics
435
runnable examples in 7 languages
523
hours of video lectures, by topic
2015→
every past paper since
Zafar Ali Khan
O & A Level Computer Science Educator · Entrepreneur · Programmer at Heart · President & Co-founder, ByteCorp · Creator of AskZ
The person behind the site
“I am not a teacher.
I am an awakener.”
A proud Pakistani educator, entrepreneur and programmer at heart: twenty-five years of O and A Level Computer Science (0478, 2210, 9618) across Karachi's most renowned institutes, thousands of students, A*s and CAIE distinctions every session, and an online following of 65,000+ wherever CAIE CS is offered. ZAK built this free platform because the resources students actually needed did not exist — so he wrote the interpreter, sorted the papers, shot the lectures and trained the tutor himself.
- The City School
- Beaconhouse
- Alpha College
- Cedar College
- Whales College
- Sceptre College
- Nixor College
- Foundation Public School
- Credo
- Heuser College
- Reads College
- DHA Public School
Testimonials
What students say.
Real students, real schools, real results — every testimonial is submitted with credentials and approved by ZAK before it appears.
O Level / IGCSE Featured
I had the privilege of being taught Computer Science by Sir Zafar Ali Khan during my O and A Levels, and I will always be deeply grateful that I was his student. He is an exceptional teacher, but what I value most is the genuine care, generosity and selflessness he has always shown me. He gave me his time, knowledge and support so freely, often going far beyond what anyone could expect from a teacher. Much of the confidence and passion for learning that I carried forward in life began in his classroom, and I truly believe his influence played a part in the person I became. Even years later, he has never hesitated to guide or help me whenever I have reached out. Some teachers leave you with good grades Sir Zafar left me with something far more lasting. I can never fully thank him for everything he has done for me, and I feel incredibly fortunate to still call him my mentor.
A Level Featured
ZAK didn’t just teach Computer Science; he had an incredible way of inspiring and uplifting his students. From supporting us in the classroom to being there for us and responding even after class hours, ZAK always went above and beyond. The love for CS that I developed started with his classes, and I’m genuinely grateful for that foundation. With technology evolving so rapidly, I can only imagine how much more enriching the experience of learning from him must be today
A Level Featured
I was fortunate to study A-level Computer Science with this teacher in Pakistan. He made the classroom welcoming, explained difficult concepts clearly, and always made learning enjoyable. His teaching has stayed with me well beyond A-levels. The foundation he gave me in computer science, especially low-level languages, has been incredibly helpful as I study at Simon Fraser University in Canada. Many of the concepts we covered and assignments we completed prepared me for my first- and second-year university courses. He is a friendly, dedicated, and truly excellent teacher. I’m grateful for the confidence and strong foundation he helped me build.
Every May
ZAKATHON
Marathon revision workshops right before the CAIE papers. Started as an experiment with a few students in a room, now fills an auditorium every year.
About the endeavourLearn with ZAK in person
Small-group classes for O Level, AS and A2 across 5 centres in Karachi, plus live online sessions for students anywhere.
Centres & registration Cloud drives
Success Packs
Everything ZAK gives his own students, in one drive. ZAK's notes, tests and mocks plus every CAIE paper, mark scheme and examiner report — one drive per level, updated every session.
What's insideWatch ZAK teach it
Every lecture, indexed by syllabus topic.
588 videos — 523 hours — from ZAK's YouTube channel, each tagged with the topic it teaches. New uploads land here on their own. These are the latest; press play.
A2202633 views
O Level20265 views
A220262 views
From the blog
Exam technique, study skills, real talk.
70 posts from ZAK, pulled live from the blog.
- How Cambridge grades your paper: grade thresholds, the A*, IBCC equivalence and the awardsUsSalam-o-AlaiKum. I first wrote this page in May 2011. It became the most read post on this blog, with more than twelve thousand visits, and students still send it to each other every August and… · 19 min · Blogger
Video - Computer Science after A Level or Inter: which degree, and why they are not the same thingUsSalam-o-AlaiKum. Every November the same message lands in my WhatsApp conversations. "Sir, CS or Software Engineering? Is AI better? · 8 min · Blogger
Video - Why every cover of my new books is a heat map of the examBismillah. For years students have asked me one question more than any other: "Sir, which book should I follow?" Today I can finally give a complete answer. · 2 min · Blogger
Your A* starts with one topic.
Pick a level, open a topic, read the notes, run a bit of pseudocode — or Python, SQL, assembly, Prolog — and try the assignment. That's it. Come back tomorrow and the streak counter does the rest.
