Software Engineer I, Backend (Collections)

A foundations course that builds eleven core data structures from the ground up (arrays, matrices, stacks, queues, linked lists, trees and BSTs, hash tables, hash sets, heaps, graphs and tries), then covers sorting, searching, greedy and divide and conquer. Every chapter has practice problems, flashcards and an assessment. It suits students and career switchers whose foundations came from tutorials and who find pattern courses move too fast.

• Job search
• DSA
• CS fundamentals

A structured learning path through coding interview preparation that brings together data structures and algorithms fundamentals, recursion and the pattern-based approach to coding questions in one order. It totals 77 chapters and 1,054 lessons, with quizzes, flashcards and a certificate. Use it when you have plenty of material but no clear plan for what to study first.

• Job search
• DSA
• Career

A free newsletter of short, focused posts on system design and problem solving, from the team behind the Grokking courses. Recent posts cover company interview processes (such as OpenAI and Anthropic roles), the most asked mobile system design questions and preparation plans, each linking to a fuller article on the blog. It suits engineers who want a steady, low-effort way to keep system design and interview topics fresh between deeper study sessions.

• System design
• DSA

The second volume of Grokking the System Design Interview, aimed at senior and staff (L5/L6) design rounds. It works through harder case studies such as a payment system, flash sale, notification service, unique ID generator, Gmail, Reddit, Google Calendar and a code judging system, then goes beneath them with patterns like quorum, write-ahead logs and vector clocks and deep dives into Dynamo, Cassandra, Kafka, Chubby, HDFS, GFS and BigTable.

• System design
• Backend
• Job search

MIT's full undergraduate algorithms course from Spring 2020, free on OpenCourseWare with lecture videos, notes, problem sets, quizzes and exams with solutions, taught in Python by Erik Demaine, Jason Ku and Justin Solomon. It covers data structures, sorting, hashing, trees, graph search, shortest paths and dynamic programming with the reasoning behind each, which is what lets the ideas transfer to new problems.

• DSA
• CS fundamentals
• Programming

A very large site of articles on data structures, algorithms and core CS subjects such as operating systems, DBMS, computer networks and OOP, usually with code in several languages, plus practice problems and paid courses. It is handy for revising a university topic or finding a worked example of a specific algorithm. Quality varies because much is community written, so cross-check anything surprising against a textbook or official documentation.

• DSA
• CS fundamentals
• Databases