# SkillJev Taxonomy v0.1 — Backend / Fullstack (IT/Engineering)

10 competency groups (a JD maps to 6–10 of them = radar axes). Each group has stable `group_id`; skills are leaves (`skill_id`, lowercase snake_case). The **skill head** predicts `group_id`.

| group_id | Name | Example skills (leaves) |
|---|---|---|
| `lang_core` | Programming Languages & Core CS | java, go, python, node_ts, kotlin, rust, concurrency, data_structures |
| `api_design` | API & Service Design | rest, grpc, graphql, api_versioning, idempotency, openapi |
| `data_storage` | Data Storage & Modeling | postgresql, mysql, mongodb, redis, schema_design, query_optimization, migrations |
| `system_design` | Distributed Systems & Architecture | microservices, event_driven, kafka, caching_strategy, scalability, consistency |
| `cloud_devops` | Cloud, Containers & Delivery | aws, gcp, docker, kubernetes, terraform, ci_cd |
| `reliability_obs` | Reliability & Observability | monitoring, tracing, slo_sli, incident_response, performance_tuning |
| `security` | Application & Infra Security | authn_authz, oauth_oidc, owasp, secrets_mgmt, encryption |
| `testing_quality` | Testing & Code Quality | unit_testing, integration_testing, tdd, code_review, static_analysis |
| `frontend` | Frontend (fullstack roles) | react, typescript_fe, state_mgmt, web_performance, accessibility |
| `leadership` | Technical Leadership & Collaboration | mentoring, tech_design_docs, cross_team, ownership, hiring |

Rules
- One requirement → exactly one primary `group_id` (secondary groups allowed in `meta.secondary_groups`, not trained in v1).
- Unmapped skills → `other` (kept out of v1 training; logged for taxonomy growth).
- Synonyms normalized in `taxonomy/aliases` (e.g. "k8s"→kubernetes, "Postgres"→postgresql, "AWS ECS"→aws+docker).
- Taxonomy is versioned (`taxonomy_version: "0.1"`); every sample stores it.