Topics
Pick a path. Each topic groups maps you can finish in a sitting.
System design
18 studiesCapacity, trade-offs, and request paths you can defend on a whiteboard.
rate-limiting · sharding · queues
APIs
24 studiesHTTP semantics, retries, idempotency, GraphQL tradeoffs, and contract design.
http · rest · graphql · idempotency
Caching
8 studiesLatency wins, stampede control, and invalidation that does not lie.
redis · ttl · cache-aside
Databases
42 studiesIndexes, isolation, storage engines, shard and partition keys, and zero-downtime migrations you can ship without a maintenance window.
indexes · transactions · storage · migrations · partitioning · shard-keys
Networking
30 studiesTCP, TLS, load balancers, and why the p99 lives in the handshake.
tcp · tls · lb
Concurrency
18 studiesLocks, isolation, and the bugs that only show up in production.
locks · async · races
Observability
17 studiesSLIs, traces, and the dashboard you would actually page on.
metrics · tracing · sli
AI / ML
59 studiesRetrieval, embeddings, vector indexes, evals, and serving patterns for senior interviews.
rag · embeddings · evals · serving
SQL
18 studiesQuery plans, joins, and the index the interviewer hopes you mention.
joins · plans · window-functions
Messaging
17 studiesKafka, event-driven architecture, outbox and CQRS, WebSockets, MQTT, and queues you can defend in interviews.
kafka · eda · outbox · queues
Data engineering
29 studiesPipelines, sketches, approximate aggregations, object storage, and stream processing with event time, windows, and exactly-once sinks.
sketches · pipelines · aggregations · object-storage · stream-processing
Distributed systems
41 studiesRaft consensus, replication, consistent hashing, saga-style distributed transactions, two-phase commit, and conflict-free replicated data types.
raft · consensus · replication · sagas · two-phase-commit · crdt
Security
31 studiesAuthN, AuthZ, OAuth/OIDC, OWASP web attacks (injection, XSS, CSRF, SSRF, CORS), secrets/KMS, tokens, and service identity you can defend in interviews.
oauth · oidc · jwt · mtls · authz · secrets · kms
DevOps
42 studiesKubernetes workloads, CI/CD pipelines, artifact digests, supply-chain controls, Git rebase, merge, and recovery, and Terraform state, modules, and safe change you can defend in interviews.
kubernetes · deployments · probes · rollouts · cicd · supply-chain · git · terraform · iac
Performance
6 studiesProfiling, flame graphs, latency budgets, and load tests you can defend in interviews.
profiling · flame-graphs · latency · p99
Testing
7 studiesPyramid, contracts, property-based tests, doubles, and flakes you can defend in interviews.
test-pyramid · contracts · property-based · flakes
DSA & Algorithms
37 studiesInterview pattern map — arrays to DP/backtracking — with Big-O, templates, and LeetCode drills.
dsa · algorithms · leetcode · patterns · big-o
Frontend
6 studiesBrowser and PWA internals: service workers, the rendering pipeline, and the multi-process model you can defend in interviews.
pwa · service-workers · browser-engines · rendering
Language Internals
34 studiesJavaScript, Python, Rust, and Go runtimes, plus TypeScript and Python typing: ownership, event loops, the GIL, goroutines, and packaging.
javascript · python · rust · go
Engineering practices
6 studiesTimed interview debugging: find the signal, reproduce, ship the smallest fix, then design one component.
debugging · cloudwatch · interview
Operating systems
12 studiesVirtual memory, paging, the page cache, and Linux I/O models: blocking calls, epoll, io_uring, and event-loop backpressure.
virtual-memory · paging · tlb
High-level design
6 studiesHLD interview and machine-coding scale-up: capacity, APIs, data model, caching, sharding, and the path from a single-node solution to production.
hld · url-shortener · system-design · machine-coding
Low-level design
12 studiesOOP and SOLID class design for machine-coding LLD: interfaces, invariants, in-memory state, and concurrency you can implement and test.
lld · ood · machine-coding · concurrency
Reliability & Disaster Recovery
6 studiesRTO and RPO, backups and PITR, multi-region failover, and cells with static stability you can defend in interviews.
disaster-recovery · rto · rpo · multi-region · failover