Cheat Sheets
Every subject on one page. For the last hour before a test or an interview.
One dense, printable page per subject: the definitions, formulas, patterns and numbers that come up again and again in placement tests and interviews. Read one in ten minutes, or print it and keep it with you.
- Revise a whole subject in about ten minutes
- The formulas, patterns and must-know facts, without the long explanations
- Print any sheet, or save it as a PDF
CS Theory
Operating systems, DBMS, computer networks and OOP.
Operating Systems
Processes and threads, CPU scheduling, synchronisation, deadlocks, memory, paging and disk scheduling on one page.
DBMS
Keys, normalisation, ACID, isolation levels, locking, indexing, ER modelling and SQL command groups on one page.
Computer Networks
The OSI and TCP/IP layers, TCP vs UDP, ports, IP addressing and subnets, what happens when you open a URL, devices and protocols on one page.
OOP
The four pillars, overloading vs overriding, abstract class vs interface, access modifiers, constructors, key keywords, relationships and SOLID on one page.
Coding
DSA patterns, Java for coding tests, recursion and DP, and SQL.
DSA Patterns
What fits in the time limit, the cost of every common data structure and sort, a clue-to-pattern table, and the templates for binary search, sliding window, graphs and trees.
Java for Coding Tests
The Java collections, snippets, sorting, string methods and integer traps you need in a timed coding test.
Recursion & DP
The recursion recipe, base-case values, pick-or-skip and backtracking templates, the 4 memo steps, table loop order and the six DP patterns on one page.
SQL
Query order, joins, GROUP BY vs HAVING, NULL rules, window functions, CTEs and the classic interview queries on one page.
Aptitude
Quantitative formulas, logical reasoning and verbal ability.
Quantitative Aptitude
Every formula for percentages, profit and loss, interest, ratios, mixtures, time and work, speed, numbers, permutations, probability, clocks and calendars.
Reasoning & Verbal
Quick methods for series, coding-decoding, blood relations, directions, syllogisms, seating arrangements, data sufficiency, reading comprehension and sentence correction.
System Design and ML
The building blocks and numbers to know, and the machine learning essentials.
System Design
The interview framework, numbers to estimate with, scaling, caching, databases, CAP, queues, reliability and the key idea behind common designs on one page.
Machine Learning
Types of learning, bias vs variance, evaluation metrics, the main algorithms, gradient descent, neural networks, data preparation and LLM basics on one page.