learn.surkar.in / CS Fundamentals

Senior Engineer
Fundamentals

The mental models, mechanisms, and trade-offs that separate engineers who understand systems from those who merely use them. Each page: deep theory + visual diagrams + a quiz to test yourself.

36topics

12domains

0drill cards

0due today

Open Drill Mode View Study Stats

Hardware & Compute

3 topics

CPU Architecture

Fetch-decode-execute, pipelining, out-of-order execution, branch prediction, caches (MESI), SIMD, speculative execution & Spectre/Meltdown.

Memory Hierarchy & RAM

Latency numbers every engineer must know, DRAM, virtual memory, TLB, page faults, mmap, CoW, allocators, garbage collection.

HDD vs SSD internals, NVMe, RAID levels, file systems (ext4, XFS, ZFS), WAL, durability guarantees, fsync.

Operating Systems

5 topics

PCB, process states, fork/exec, CoW, memory layout (text/data/heap/stack), CFS scheduler, context switching, IPC.

Threads & Concurrency

Threads vs processes, sync primitives (mutex/semaphore/CAS), deadlock, livelock, epoll/io_uring, actor model, async/await.

Kernel & System Calls

Kernel space vs user space, syscall mechanics, monolithic vs microkernel, Linux subsystems, namespaces & cgroups (foundation of containers).

Linux Internals

Boot process, systemd, strace/perf/proc/sys, networking tools, file permissions, SELinux/AppArmor, seccomp, capabilities.

Encoding & Serialization

UTF-8, IEEE 754 (why 0.1+0.2≠0.3), Base64, protobuf/Avro/JSON comparison, schema evolution, gzip/Brotli/zstd/LZ4.

Networking

4 topics

Network Models & Layers

OSI 7-layer model, TCP/IP model, encapsulation, Ethernet, ARP, VLANs, IPv4/IPv6, ICMP, BGP, OSPF.

3-way handshake, state machine, congestion control (CUBIC/BBR), sliding window, Nagle, TIME_WAIT, HOL blocking → QUIC.

Resolution flow, all record types, DNSSEC, DoH/DoT, amplification attacks, split-horizon, service discovery.

HTTP & Web Protocols

HTTP/1.1 → 2 → 3 (QUIC), status codes, WebSockets, SSE, gRPC/protobuf, full version comparison.

Web Fundamentals

2 topics

Browser Internals

Critical rendering path, V8 (hidden classes/JIT), event loop, microtasks vs macrotasks, service workers, Core Web Vitals.

SOP, CORS, XSS (reflected/stored/DOM), CSRF, CSP, SameSite cookies, clickjacking, SSRF, OWASP Top 10.

Cryptography & Security

3 topics

Symmetric Encryption

AES-GCM deep dive, ChaCha20-Poly1305, SHA-256/SHA-3 hashing, HMAC, KDFs (Argon2/bcrypt/PBKDF2), digital signatures.

TLS 1.2 vs 1.3 handshake, certificate chain, OCSP, PFS, cipher suites, SNI, mTLS, Let's Encrypt/ACME.

Authentication & Authorization

JWT pitfalls, OAuth 2.0 flows (PKCE, Client Credentials), OIDC, SAML, WebAuthn/FIDO2, RBAC vs ABAC.

Data Structures

3 topics

Data Structures→

Arrays, Lists, Stacks & Queues

Contiguous vs linked, dynamic arrays (amortized O(1)), ring buffers, LRU cache, Bloom filter, skip list, Union-Find.

Data Structures→

Hash functions, chaining vs open addressing, Robin Hood hashing, cuckoo hashing, consistent hashing, real-world internals.

Data Structures→

BST, AVL, Red-Black, B+ Tree (databases), heap (priority queue), trie (autocomplete), Segment Tree, Fenwick Tree.

Algorithms

3 topics

Sorting Algorithms

O(n log n) lower bound proof, quicksort, mergesort, heapsort, Timsort, counting/radix/bucket sort, full comparison table.

Graph Algorithms

BFS, DFS, Dijkstra, Bellman-Ford, A*, Floyd-Warshall, Kruskal/Prim MST, topological sort, SCC, max flow.

Dynamic Programming

Overlapping subproblems, memoization vs tabulation, knapsack, LCS, edit distance, space optimization, DP vs greedy.

Databases

2 topics

NoSQL Databases

Document (MongoDB), key-value (Redis/DynamoDB), column-family (Cassandra), graph (Neo4j), time-series, CAP theorem, PACELC.

Database Internals

B-Tree vs LSM-Tree, WAL, buffer pool, query optimizer, MVCC, read/write/space amplification trade-offs, connection pooling.

Infrastructure

5 topics

Infrastructure→

Caching Strategies

Cache-aside, write-through, write-behind, LRU/LFU/W-TinyLFU, stampede, penetration, avalanche, hot key, Redis, CDN.

Infrastructure→

Message Queues & Events

Kafka (commit log, partitions, ISR), RabbitMQ (exchanges), SQS/SNS, event sourcing, CQRS, saga pattern.

Infrastructure→

Distributed Systems

8 fallacies, Lamport/vector clocks, Raft consensus, consistency models, replication, consistent hashing, 2PC, saga, FLP impossibility.

Infrastructure→

Docker & Containers

Namespaces + cgroups + overlay FS, Dockerfile best practices, multi-stage builds, networking, volumes, security hardening.

Infrastructure→

Control plane, core objects (Pod/Deployment/Service), networking (CNI, NetworkPolicy), HPA/VPA, scheduling, deployment strategies.

Cloud Computing

2 topics

Cloud Fundamentals

IaaS/PaaS/SaaS/FaaS, VPC (subnets, SG vs NACL), IAM (least privilege, policy evaluation), EC2, S3, RDS/Aurora, cost optimization.

Git internals (DAG, index), CI pipelines, blue-green/canary deploys, feature flags, Terraform/GitOps, immutable infra.

Performance & Observability

2 topics

Performance Engineering

P99 latency (why averages lie), Amdahl's Law, Little's Law, flame graphs, load/stress/soak testing, N+1, connection pooling.

Three pillars (logs/metrics/traces), RED & USE methods, Prometheus/Grafana, OpenTelemetry, SLOs, error budgets, burn rate alerting.

Architecture & Design

2 topics

Architecture→

Requirements estimation, scalability, HA patterns, API design (idempotency/pagination/versioning), rate limiting, circuit breakers.

Architecture→

Software Architecture

Monolith vs microservices, event-driven, hexagonal/clean architecture, DDD (bounded contexts, aggregates), SOLID, design patterns.

No topics match that filter.