Learn it properly, then prove it.
Full courses taught idea first, then traced by hand, then coded — with a step-through simulator in almost every lesson that you drive yourself. No account, no payment, no autoplay.
DSA: Zero to Placement Ready
A complete Data Structures and Algorithms track for engineering students, assuming no prior coding at all. It starts at writing your first program and ends at defending your approach in an interview. Every topic is taught idea first, then traced by hand on a small example, then coded naive and optimised, and closes with the interview questions and practice problems that topic actually attracts.
- 01
Getting Started with Code
Beginner4 lessonsYour first program, the types your data lives in, the operators that combine it, and the branching that makes it decide.
- 02
Loops and Pattern Printing
Beginner2 lessonsRepetition, dry running with trace tables as a graded skill, and the i-j reasoning gymnasium that everything later depends on.
- 03
Functions and Data Containers
Beginner5 lessonsNaming and reusing code, then the containers you will spend the rest of the course filling: arrays, strings, matrices and the standard library.
- 04
Complexity and Math
Beginner2 lessonsHow to count what your code costs before you run it, and the number theory that shows up in interview problems.
- 05
Recursion and Bits
Intermediate2 lessonsThe call stack drawn out frame by frame, and the bit operations that turn arithmetic tricks into one-liners.
- 06
Sorting and Searching
Intermediate4 lessonsFour algorithms built from scratch and compared honestly on stability, adaptivity and cost - not on reputation.
- 07
Array and String Patterns
Intermediate4 lessonsThe named patterns interviewers actually test, and the recognition skill that lets you name the right one from the problem statement.
- 08
Linear Data Structures
Intermediate3 lessonsPointer rewiring, the monotonic stack that collapses a quadratic scan to linear, and the queues behind sliding windows and BFS.
- 09
Trees, Heaps and Tries
Advanced4 lessonsNon-linear structures: traversals as one recursion with the visit moved, the BST property, the heap array trick, and prefix trees.
- 10
Graphs and Algorithmic Techniques
Advanced5 lessonsTraversal on graphs and grids, then the four techniques that solve most hard problems: backtracking, dynamic programming, greedy and the advanced structures.
- 11
Interview Preparation
Advanced3 lessonsCore CS revision, the six-step method run end to end on a real problem, and what each company track actually tests.
DBMS: From Files to Transactions
A complete Database Management Systems course for engineering students, assuming no prior database experience. It starts at the difference between data and information and ends at serialisable schedules, taking in ER modelling, the relational model, SQL and normalisation on the way. Every topic is taught idea first, then shown running on a small concrete example you can step through yourself, then closed with the interview questions and practice that topic actually attracts.
- 01
Foundations of Database Systems
Beginner3 lessonsWhat data, a database and a DBMS actually are, the file-system problems that made database software necessary, and the people who run it.
- 02
DBMS Architecture
Beginner4 lessonsThe three levels a database is described at, what data independence buys you, schemas versus instances, the four families of database language, and how the tiers are laid out.
- 03
The ER Model
Intermediate5 lessonsModelling a real situation before you build any table: entities, attributes, relationships, cardinality, weak entities, and the extended features of specialisation and aggregation.
- 04
The Relational Model
Intermediate4 lessonsTables done properly: relations and tuples, the full family of keys, the constraints that keep data honest, and the rules for turning an ER diagram into tables.
- 05
SQL
Advanced6 lessonsThe language itself, from CREATE TABLE to views, with the query evaluation order, grouping, joins and subqueries taught by running them a step at a time.
- 06
Normalization and Transactions
Advanced5 lessonsWhy a badly designed table corrupts itself, how to decompose it through 1NF to BCNF, and how transactions and schedules keep concurrent work correct.
Computer Networks: From Wire to Web
A complete Computer Networks course for engineering students, assuming no prior networking experience. It starts at what a network is and ends at the TLS handshake behind the padlock in your browser, taking in the OSI and TCP/IP models, framing and error detection, IP addressing and subnetting, routing, TCP's handshake and congestion control, DNS, HTTP and network security on the way. Every topic is taught idea first, then shown running on a small concrete example you can step through yourself, then closed with the interview questions and practice that topic actually attracts. The final lesson answers the question every interviewer asks: what happens when you type a URL and press Enter.
- 01
Networking Basics
Beginner4 lessonsWhat a network is and what it buys you, how networks are classified by scale and wired by topology, the two ways to arrange who serves whom, and every device from repeater to router pinned to its layer.
- 02
OSI and TCP/IP Models
Beginner3 lessonsWhy the stack is layered at all, the seven OSI layers and what each one owns, the four layer TCP/IP stack that actually runs the Internet, and what happens to your data as it is wrapped on the way down and unwrapped on the way up.
- 03
Physical and Data Link
Intermediate5 lessonsWhat the bits physically travel through, the four delays that add up to latency, how a frame is addressed and delimited, how a receiver detects that bits changed, and how a frame finds the right machine on a LAN.
- 04
Network Layer
Intermediate6 lessonsThe addressing that gets a packet across the planet: IPv4 and its classes, subnetting and CIDR worked bit by bit, private space and NAT, how a router chooses a path, the diagnostics built on ICMP, and what IPv6 changed.
- 05
Transport Layer
Advanced5 lessonsDelivery to a process rather than a machine: ports and sockets, the TCP and UDP trade-off, the three way handshake and teardown, keeping a fast sender from drowning a slow receiver, and keeping the network itself from collapsing.
- 06
Application Layer and Security
Advanced7 lessonsThe protocols you use every day and the ones protecting them: DNS, HTTP and HTTPS with cookies and caching, email and file transfer, DHCP, firewalls and VPNs, TLS, and a capstone that walks one URL through every layer in the course.
Quantitative Aptitude: Models and Methods
A complete quantitative aptitude course built the way the topics are actually set in placement papers and competitive exams: as a small number of recognisable models per chapter, each with a method and a shortcut. It starts at number classification and divisibility, then works through percentages, ratio and proportion, simple and compound interest, profit, loss and discount, time and work, pipes and cisterns, boats and streams, ages, partnerships and mixtures. Every model is taught idea first, then shown worked once on small hand-checkable numbers, then given a step-through console so you can change the givens and watch the method rather than the answer. Each lesson closes with the interview questions and the practice that model actually attracts, including the traps examiners set deliberately.
- 01
Number Foundations
Beginner2 lessonsThe layer every other chapter assumes: classifying a number on sight, predicting whether a result must be odd or even, and finding a factor without dividing. Divisibility rules are taught as four families with a reason each, so a forgotten rule can be rebuilt.
- 02
Percentages
Beginner9 lessonsThe single most reusable chapter in the syllabus. Percentage change, the fraction multipliers worth memorising, and the models built on them: comparison, successive change, the remaining model, salary, election and examination marks.
- 03
Ratio and Proportion
Beginner13 lessonsReading a ratio sentence correctly and then dividing, connecting, and changing ratios. Includes the thirteen sentence patterns that translate English into a ratio, the coins concept, unit conversion traps, and income, expenditure and savings.
- 04
Simple Interest
Beginner4 lessonsInterest charged only on the original principal. Three models: finding any one of the five quantities, relation questions where the principal cancels out entirely, and two-condition comparisons solved by subtracting what the conditions share.
- 05
Compound Interest
Intermediate7 lessonsInterest charged on interest, and every place that differs from the simple case. Basic calculation, compounding periods from annual to quarterly, rates that change year to year, the interest earned in one particular year, and repeated-growth multiples.
- 06
Profit, Loss and Discount
Intermediate7 lessonsCost price, selling price and marked price kept straight, then profit and loss percentages, the dishonest-dealer questions, discount on marked price, successive and equivalent discounts, and the reverse questions that hide the second discount.
- 07
Time and Work
Intermediate9 lessonsWork as a rate rather than a quantity, and the LCM-units method that removes fractions from the whole chapter. Seven models: the basic together case, alternate days, joining and leaving, the chain rule, wages, efficiency, and mixed groups of workers.
- 08
Pipes and Cisterns
Intermediate5 lessonsTime and work with one addition: a pipe that empties works at a negative rate. Two filling pipes, filling against emptying, pipes closed part way through, alternate opening patterns, and faster-slower efficiency comparisons.
- 09
Boats and Streams
Advanced6 lessonsTwo speeds that add going downstream and subtract coming back, and the four formulas that follow. Finding speeds and ratios, finding time and distance, and the round-trip models where the average speed is not the average of the speeds.
- 10
Problems on Ages
Advanced8 lessonsTranslating time-travel sentences into equations, with the constant age gap as the anchor. Six models: matched time shifts, fractional and percentage multipliers, split time travel, birth and marriage milestones, shifting family averages, and long multi-person chains.
- 11
Partnerships
Advanced6 lessonsProfit shared in proportion to money multiplied by time invested. Simple partnership, the late joiner, the complex timeline where partners both join and leave, the working partner who takes a management cut, and monthly additions and withdrawals.
- 12
Mixtures and Alligations
Advanced5 lessonsThe alligation cross as a fast weighted-average tool, and the unit rule that decides whether it may be used at all. The basic rule, repeated replacement, mixing two mixtures together, and profit computed on a mixture rather than on a pure good.