Computer science · free flashcards
Computer science flashcards: algorithms, system design, APIs, design patterns and cryptography
Interviews and day-to-day engineering lean on the same core ideas: complexity, memory, concurrency, scaling, clean APIs and testable code. These decks turn them into short, precise cards you review for a few minutes a day, so the concepts are there when you need them.
- Interview readyBig-O, data structures, system design trade-offs and design patterns, phrased the way interviewers ask.
- Concepts, not triviaEach card tests one idea, with a short example where it helps it stick.
- From basics to architectureStart with bits and memory, finish with caching, sharding and consistency models.
Computer science decks
Computer science
CS fundamentals: binary and hex, two’s complement, Big-O, stack vs heap, threads and deadlocks, CPU caches, compilers, UTF-8 and floating point.
50 cardsMorse code
Learn International Morse code: all 26 letters, the 10 digits, common punctuation and signals like SOS, each with its rhythm and a memory aid.
50 cardsDS & Algorithms
Big-O for arrays, hash maps, heaps, trees and graphs, sorting trade-offs, and the patterns behind interview problems: two pointers, sliding windows, BFS, Dijkstra and DP.
50 cardsDesign patterns
SOLID, DRY, KISS and YAGNI, plus the Gang of Four patterns used most: singleton, factory, builder, adapter, decorator, observer, strategy, command and more.
50 cardsSoftware testing
Software testing fundamentals: the test pyramid, unit, integration and E2E tests, TDD, mocks vs stubs vs fakes, coverage, mutation and property-based testing.
50 cardsAPI design
API design fundamentals: REST, HTTP methods, status codes, pagination, versioning, OAuth 2.0 and JWT, CORS, OpenAPI, GraphQL, gRPC and webhooks.
50 cardsSystem design
System design fundamentals: load balancers, caching, CDNs, replication and sharding, CAP, consistency, queues, rate limiting and back-of-the-envelope math.
50 cardsCryptography
Cryptography flashcards: AES modes, RSA, elliptic curves, Diffie–Hellman, hashing, HMAC, signatures, password hashing, TLS 1.3 and common pitfalls.
50 cardsHow spaced repetition works
- Step 1See a cardRecall the answer before you flip it. Effortful recall is what builds memory.
- Step 2Grade yourselfAgain, Hard, Good or Easy. Each answer sets when the card comes back.
- Step 3Review just in timeCards return right before you would forget them: minutes, then days, then months.
Frequently asked questions
Are these decks good for coding interviews?
Yes. Data structures and algorithms, system design, API design and design patterns cover the most common interview topics, and spaced repetition keeps them fresh between interviews.
Do I need a computer science degree to start?
No. The computer science basics deck starts from binary, memory and processes, and every card explains its answer.
Is code included?
Yes, short snippets where they make a concept concrete, in languages like Python, Java and TypeScript.
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