Cheat sheets
Dense one-pagers for last-minute revision. Open one, hit print (or save as PDF) and stick it on your wall the night before the interview.
48 must-know facts & snippets
From unknown to infer, on one page
Partial → Awaited, all of them
Rendering to Server Components, on one page
Every hook, one example each
Signals to guards, standalone-first
The 30 operators you'll actually use
Semantics to grid, cascade to stacking
App Router, RSC, caching and actions
Event loop to streams, checked on Node 22
OOP to virtual threads, on one page
Beans to JWT and @Transactional, one page
Core Python to asyncio, on one page
DDD to sagas, retries and tracing
Joins to MVCC, every query run on Postgres 16
BSON to sharding, with the defaults that matter
Goroutines to generics, slices to context
Dockerfile to Compose, layers to PID 1
Pods to Helm, plus a troubleshooting table
Data types to Cluster slots, Redis 7.4/8
EC2 to IAM to DR, the services that come up
Staging area to canary deploys, on one page
Partitions to transactions, KRaft era
GlideRecord to update sets, on one page
Big-O to DP, with Python templates
Rendering to caching, plus five mini-designs
Bayes to CUPED, p-values to regression
Bias-variance to boosting, metrics to leakage
Backprop to KV cache, Adam to LoRA
Tokens to agents, RAG to guardrails
Pipelines to PSI, registry to rollback