The Gnoseed library
Every topic, browseable by category. Chasing a goal instead? Try the guided paths.
Pick a category, dive into the quizzes
5,065 questions across 38 categories. Each category holds a set of focused quizzes you can drill independently.
Kubernetes
Cluster architecture, workloads, networking, storage, config and security — plus ops and real-world scenarios.
AI & LLMs
How models work, prompt engineering, building apps, customizing and deploying LLMs in production.
Linux
Practical DevOps Linux, performance troubleshooting, Bash & shell scripting, plus the full LPIC-1 101 & 102 exam objectives.
Claude Certification
Prep for the Claude Certified Developer — Foundations (CCDV-F) exam — the Messages API, model selection, cost and tokens, and building agents.
AWS Cloud Practitioner
Two tiers for the AWS certification path — CLF-C02 fundamentals (cloud concepts and economics, shared responsibility and IAM, core services, billing and support) and the SAA-C03 trade-off tier above it, where the question stops being what a service is and becomes which one, at what cost, and what breaks at scale.
HTTP & Networking
Network fundamentals — the OSI and TCP/IP models, subnetting, DNS and firewalls — plus HTTP protocols, status codes, TLS and the nginx web server.
Git & GitHub
Version control with Git and collaboration on GitHub — branching, merging, remotes, pull requests, GitHub Actions, and repository governance.
DevSecOps
Shift-left culture, the software factory and CI/CD, containers and service mesh, zero trust, and cATO governance.
PostgreSQL
JSONB, index strategies, EXPLAIN, MVCC and vacuum — plus the advanced tier: constraints as business rules, temporal data, write skew and capacity judgment.
Terraform
HashiCorp Terraform Associate — fundamentals through advanced state and modules.
GitOps
Continuous delivery the GitOps way — the OpenGitOps principles, Argo CD and the Application model, repo patterns and sync strategies, and the Flux toolkit for multi-cluster.
SRE
Reliability targets and error budgets, incident management, toil and automation, DORA metrics, and resilience practices.
Interview Prep
Open-answer practice for real interviews — no multiple choice. You answer out loud, then compare against one model answer and a checklist of what a strong reply covers.
Service Mesh
Sidecars and ambient mode, traffic management, mTLS, resilience and mesh observability — Istio and Linkerd concepts.
Supply Chain Security
SBOMs and PURL, SLSA build provenance and Sigstore signing, dependency risk, EPSS and KEV prioritization, VEX, and artifact integrity.
Serverless & Event-Driven
The execution model behind functions — cold starts and concurrency, sync, async and poll-based triggers, CloudEvents and dead-letter handling, orchestration with Step and Durable Functions, Knative, Cloud Run and edge isolates, plus quotas and cost.
Web Security
The browser security model, XSS and CSRF, security headers, authentication, and web threat modeling.
Micro-Frontends
Frontend architecture at scale — the landscape, principles, DDD, composition, communication and modern tooling.
MITRE ATT&CK
Adversary tactics and techniques, mitigations and detection strategies, threat-intel objects, and threat-informed defense.
Argo Workflows & Events
The other half of the Argo Project — container-native pipelines where every step is a Pod, template types and reusable WorkflowTemplates, artifacts and DAG fan-out, and the EventSource, EventBus and Sensor chain that fires them from outside events.
Ansible
Agentless configuration management — inventory, modules and idempotency, playbooks with handlers and Jinja2 templates, roles and collections, plus Vault, loops and privilege escalation.
Helm
Charts, templating, releases, values and the Helm package workflow.
Python
Types and data structures, control flow, functions, OOP and the gotchas every Pythonista should know.
SQL
Queries, joins, aggregation, window functions, data modeling and transactions — standard SQL for every engine.
EU Cyber Resilience Act
The EU regulation for products with digital elements — scope and carve-outs, manufacturer duties and support periods, Annex I requirements, CE marking, and the 24-hour reporting clock.
Prometheus
Metrics, PromQL, exporters, alerting and observability fundamentals.
Go
Syntax, goroutines, channels, interfaces and idiomatic Go patterns.
Podman
Daemonless, rootless containers — pods, user namespaces, Buildah and Skopeo, and systemd Quadlet.
containerd
The runtime beneath Docker and Kubernetes — shims and runc, OCI specs, the CRI, snapshotters, and ctr/nerdctl.
AI & Model Security
OWASP LLM application risks, attacks on models themselves, MLSecOps provenance and AI-BOM, AI in the SDLC, and NIST AI RMF, ISO 42001 and the EU AI Act.
Docker
Images, layers, Dockerfiles, volumes, networks and container basics.
Observability
The three signals and RED/USE, structured logging and Loki, distributed tracing with spans and sampling, OpenTelemetry, and Grafana.
etcd
The distributed key-value store behind Kubernetes — MVCC, leases, Raft consensus, quorum, backup/DR and the K8s datastore.
Cilium
eBPF-powered Kubernetes networking, security and observability — identity-based policy, L7/DNS rules, Hubble and kube-proxy replacement.
Secure Coding
Authentication, access control, input validation, crypto and safe logging — app-security fundamentals.
Falco
CNCF runtime security for Kubernetes — syscall/eBPF detection, the rules language, threat scenarios and the falcosidekick ecosystem.
OPA / Gatekeeper
CNCF policy-as-code — the OPA engine and Rego, Gatekeeper constraints and admission control, plus OPA beyond Kubernetes.
JavaScript
Types, scope, closures, async and the quirks every dev should know.