Software Engineer Interview Notes: DSA Patterns, OOP, DBMS, OS and Networks

B.Tech, BCA and MCA final-year students and freshers preparing for software engineer and SDE-1 interviews get one set of interview-depth notes instead of scattered textbooks, videos and forum posts. Each topic gives the idea, the follow-up questions interviewers ask, and small code that actually runs, with tests.

What's inside

• Software-Engineer-Interview-Notes.pdf: 108 A4 pages
  • 16 DSA patterns: two pointers, sliding window, prefix sums, hashing, binary search on the answer, stack and monotonic stack, queue and deque, linked lists, recursion and backtracking, trees and BSTs, heaps and top-K, BFS, DFS and topological sort, Dijkstra, union-find, greedy with a proof sketch, and dynamic programming (1D, 2D, knapsack, LIS). Each pattern has recognition clues, a template with its complexity, an original worked problem with a dry-run table and the real output of the code, a 60-second explanation, variations, common mistakes, 3 follow-up questions with answers and 3 practice problems with solution outlines.
  • Complexity cheat sheet (2 pages).
  • OOP: the four pillars in Python and Java, SOLID with one example each, composition vs inheritance, interfaces vs abstract classes, 5 design patterns (singleton, factory, strategy, observer, builder), a small design exercise and 12 questions with answers.
  • DBMS: ER diagrams to tables, keys, normalisation to BCNF with a worked example, transactions and ACID, isolation levels and anomalies, B+ tree indexing, joins, a 2-page SQL summary, serializability, recovery and 12 questions.
  • Operating systems: processes and threads, a worked Gantt example, synchronisation and deadlock, the Banker's algorithm, disk scheduling, paging, a worked page-replacement example and 12 questions.
  • Computer networks: OSI and TCP/IP, TCP vs UDP, the three-way handshake, HTTP and HTTPS, DNS, what happens when you type a URL, subnetting with a worked example, CRC and 12 questions.