Junaid Khalid

I have sat the papers I teach

Every grade below is from the Cambridge International system, the same system Cambridge IGCSE and 9618 students are in now.

• O-Level

  Straight A* grades

  All eight subjects, Computer Science included. O-Level is the qualification Cambridge International sets at the same stage as IGCSE, and it is graded on the same scale.

• AS-Level

  Best Across Five

  A Cambridge International distinction awarded for the top aggregate mark across five AS-Level subjects. It is a comparative award rather than a grade, so it says something a transcript of grades does not.

• A-Level

  Straight A grades

  Computer Science included. The same papers, the same mark schemes and the same examiner conventions that students sitting 9618 meet today.

Where the specification and a working codebase overlap

A syllabus topic on the left, and what that topic is in an ordinary working week on the right. This is the part a tutor who only teaches cannot offer, and it is the reason explanations in a lesson tend to arrive with a reason attached.

Databases and SQL

Designing schemas, writing queries against live databases, and finding out the hard way which missing index turns a 20 millisecond query into a 20 second one. Normalisation stops being an exam ritual once you have had to migrate a table that was not normalised.

Networks and protocols

DNS records, HTTP headers, TLS certificates, reverse proxies and CDNs, configured rather than memorised. When a question asks what a packet carries or why a request failed, the answer comes from having read the failing request.

Security

Password hashing, authentication tokens, firewall rules and web application firewalls on systems that real people log in to. The syllabus asks for the definition of a brute-force attack; production asks you to stop one.

Systems software and architecture

Linux servers, containers, process supervision, memory limits and the reason a machine falls over at 3am. Virtual memory and interrupts are on the specification because they explain behaviour you can watch.

Algorithms and complexity

Where a nested loop is entirely fine and where it takes a page down. Big O is worth marks in an exam and worth money in a codebase, and the second one is what makes it stick.

Object-oriented programming

Classes, inheritance, interfaces and composition in codebases that have to be maintained by someone else later. Most students can define encapsulation. Far fewer can say what goes wrong without it, which is what the higher mark bands ask for.

Programming and testing

Python, TypeScript and SQL, most days. Reading a stack trace, forming a hypothesis and proving it is the same skill as an exam question that hands you nine lines of broken code and asks you to state the error.

What I help with, and what I will not do

Lessons cover theory, programming, exam technique and past-paper work, and for A-Level students the NEA coursework project. On the NEA that means planning, structuring, debugging your own code and reviewing your write-up against the mark scheme.

It does not mean writing it. Supplying coursework is against exam board rules and, in England, against the law. A tutor who offers to write your project is offering to get you disqualified, and the work would not survive a moderator reading it next to your interview notes anyway.