After the TMUA: Preparing for Your Cambridge Computer Science Interview

Cambridge Computer Science requires the TMUA of every applicant, and for two colleges it requires a second written assessment after that. Applicants to Peterhouse or Trinity also sit the CSAT, which the department says is taken “on the day of interview”. Interviews for 2027 entry run from 7 to 18 December 2026, most applicants have one or two totalling 35 minutes to an hour, and the length and format depend entirely on which college holds the application.

What Happens Between the TMUA and Your Interview Invitation

Every Cambridge Computer Science applicant sits the same admissions test. The university's course page is unambiguous: “All applicants for Computer Science are required to take the Test of Mathematics for University Admission (TMUA) at an authorised assessment centre.” The department's own admissions FAQ says the same in four words — “All applicants sit the Test of Mathematics for University Admission (TMUA)”.

What happens to that score afterwards is common to every course that uses a UAT-UK test, and we have set it out once rather than on every page: see After the TMUA for the release timing, the published score scale and UAT-UK's statement that it sets no cut score. The short version is that Cambridge has your result before you do.

What is specific to this course is what the department weighs alongside it. Asked whether an A level in Computer Science counts, it answers: “Yes. We value good marks in all subjects, albeit not always equally. Our primary focus is on Mathematics because it is taught in all schools, provides a formal underpinning for much of our course, and there is a positive statistical correlation between those who do well in mathematics at school and those who do well on our course.” The course page adds a requirement that has moved in recent cycles: “Further Mathematics is now required to AS or A level if your school offers it.”

Invitations arrive in the same window as every other Cambridge subject. The university states that “Most interview invitations are sent in November, but some might be sent in early December”, and adds something worth holding onto through that fortnight: “The timing of your interview does not reflect your perceived strength as a candidate.”

If You Applied to Peterhouse or Trinity, You Have One More Written Test

This is the single most consequential thing on this page, and none of the five competing guides we read for it carries it. Cambridge's Computer Science course page states plainly: “If you're applying to Peterhouse or Trinity you will also need to take the Computer Sciences Aptitude Test (CSAT).”

The department describes the same requirement from the general end, and adds the timing: “In addition to the TMUA test, some colleges will require candidates to sit another written assessment (such as the Computer Science Aptitudes Test (CSAT)) on the day of interview. Please check with individual colleges to determine their interview process.” The two Cambridge pages spell the name differently — one “Computer Sciences Aptitude Test”, the other “Computer Science Aptitudes Test” — so the acronym is the safe thing to use.

Three practical points follow. First, you do not arrange it: Cambridge's guidance on college assessments says “You do not need to register for College admission assessments” and that the interviewing college will tell you when and how to take it. Second, it is sat around the interview rather than weeks before, so it sits inside the same day you have already been preparing for. Third, and least comfortable: a candidate who assumed the October paper was the end of the written stage may first learn otherwise from an invitation email in late November.

The department also points candidates at a practice resource for it, listing Practice+ “For sample CSAT questions with hints and solutions” among its preparation links. If you hold an application at either of those two colleges, that is the one item on the department's list that is not optional reading.

How Long Your Interviews Are Depends on the College That Took Your Application

Cambridge does not run a single Computer Science interview format, and the department publishes three worked examples rather than a general rule: “The number and length of your interviews depends on the College that you apply to. For example, applicants to: Gonville and Caius have two 25-minute Computer Science interviews Peterhouse have one 25-minute Computer Science interview and one 25-minute Maths interview Churchill have one 30-40 minute Computer Science interview”.

Read down the second column and the three are materially different preparations. Two 25-minute subject interviews at Caius means two separate openings, two sets of interviewers and two chances to settle. Peterhouse splits the time between Computer Science and mathematics, which is a different examination of the same candidate. Churchill's single longer interview gives one continuous conversation with no reset, and it is the only one of the three where a slow start cannot be recovered in a second room.

None of that is a ranking, and the university says so about the general case: “The number of interviews you have does not relate to how strong your application is.” It is variation by college, and it is knowable in advance, which is the whole reason for reading it now rather than discovering it on the day. The department's own advice is to “consult the Computer Science page on the website of the College you applied to”.

Online or In Person: What Cambridge's 2027-Entry College Table Says

Cambridge publishes a college-by-college interview-format table specifically for this cycle, headed “Check the interview formats used by each College for 2027 entry.” It is worth counting rather than skimming, because the distribution is not what most candidates expect.

Of the 29 colleges listed in that table, 14 state that all interviews are online: Christ's, Downing, Fitzwilliam, Girton, Hughes Hall, Lucy Cavendish, Magdalene, Murray Edwards, Newnham, Queens', St Catharine's, St Edmund's, St John's and Wolfson. Four state that all are in person: Churchill, Emmanuel, King's and Selwyn. The remaining 11 — Clare, Corpus Christi, Gonville & Caius, Homerton, Jesus, Pembroke, Peterhouse, Robinson, Sidney Sussex, Trinity and Trinity Hall — make the format conditional, either on the course applied for or on where the applicant is based.

Two cautions about that count, because both matter. It describes the colleges listed in that table, not every Cambridge college. And it describes a published intention for 2027 entry: Cambridge tells applicants that “Interviews may be online or in person, depending on which College is assessing your application and the course you have applied for”, and that “You will not usually be able to request a particular format.” Your invitation is the authority for your own case.

For a Computer Science applicant there is one further detail in the table. Three colleges list course-level exceptions to their default — Clare names Medicine and Music, Homerton names Mathematics and Music, and Jesus names a longer list including Mathematics, Medicine, Philosophy and Natural Sciences (Physical). Computer Science does not appear in any of the three. That is a statement about what the table lists rather than a guarantee, but it means a Computer Science applicant to those colleges has no published exception to their default format.

What the Department Itself Says to Work On

Most preparation advice for this interview is written by people selling preparation. The department publishes its own, and it opens with a sentence that decides how the next few weeks should be spent: “Since solving Maths problems will likely form a large part of your interview, make sure to practise solving tricky problems.” It goes on: “These problems might just involve Maths, however some might focus more on algorithms or other concepts in Computer Science, such as programming and logic.”

The resource list that follows is short and specific, and the first item on it is the test you have just sat. Under maths problems it names TMUA past papers and MAT past paper questions; then the UKMT senior competitions (the Senior Maths Challenge, Senior Kangaroo and British Maths Olympiad), NRICH's problems by topic and advanced problem-solving resources, and the STEP Support Programme. Under programming problems it names Project Euler and the British Informatics Olympiad. Separately it points at Oxford's published sample Computer Science interview problems and at a sample interview dialogue for Oxford Computer Science, which it describes as “very similar to a Cambridge one”.

Re-reading your own TMUA paper is therefore not nostalgia; it is the department's first recommendation. What changes is how you work it. The department is explicit that the interview rewards a different behaviour from the test: “You should explain your approach to the problem and the steps that you are taking. Your interviewers will give you hints if you get stuck or go in the wrong direction.” It also says, plainly, “Practise talking through a problem as you solve it”, and “Practise talking about Computer Science and what interests you about it”.

And it lowers the bar where candidates tend to raise it: “The interviewers will not expect you to know things that are outside of your school curriculum and do not expect you to fully complete all of the problems presented during the interview.” A question you do not finish is not a question you have failed.

One last item on the department's list is your own application. It notes that interviewers “might ask about things that you've mentioned in your personal statement”, and gives a concrete example: if you mentioned a coding project, look at the code again, and be ready to say which algorithms you used and why you chose them rather than the alternatives.

Your Interview Falls Between 7 and 18 December 2026: What to Have Ready

Cambridge publishes a “Main interview period: 7 December to 18 December 2026” for 2027 entry, with “Winter pool interviews: around mid to late January 2027” for candidates pooled between colleges. The university is firm about the window: “You must keep the interview period free. We cannot reschedule interviews, unless under exceptional circumstances.”

If yours is online, the practical preparation is small and specific. Cambridge advises picking a quiet space, a device with a full battery, a tested webcam, microphone and connection, and pen and paper. For this subject there is one more item, and it is easy to leave too late: practise “using a stylus and tablet to annotate a shared document or whiteboard if you've applied for a science or mathematics course and your College has told you you'll need to use one in your interview”. The college may run a tech-check session; the invitation says whether it does.

That instruction exists because of what the interview asks you to do. Cambridge tells applicants “You may be asked to share your workings if the interviewers ask you a problem-solving question”, and notes that this usually happens for science and mathematics courses. Writing algebra legibly on a shared whiteboard, while talking, is a skill in its own right and nobody is good at it the first time.

One rule is worth knowing before the day rather than after it. If you are unwell or something goes wrong, tell the college first: Cambridge states that “Any illness, injury or personal circumstances that you've reported after your interview won't usually be taken into account when the College considers your interview performance.” The order matters more than the circumstance.

If your interview is in person, travel support exists and is narrower than many candidates realise: Cambridge offers it for UK students eligible for Free School Meals, with accommodation and meals possibly provided, and notes that some colleges may support others in financial need. The same eligibility applies to help with technology for an online interview.

For the wider picture across both universities — what the score did, when it arrives, and how Oxford's December differs from Cambridge's — see After the TMUA. For the ESAT side of the same fortnight, After the ESAT for Oxford Biomedical Sciences follows the same shape. And our Cambridge Computer Science interview page covers what interviewers look for and works a real question through in full.