🧠Galhoom Path — Track 5 · Foundations (stack-agnostic notes — not a language Study series).
Stack-agnostic study notes for shared backend engineering—topics that recur across most backend jobs, independent of PHP, Laravel, Node, Django, Spring, or any other language/framework track.
Those stack-specific repos stay separate. This repo is the common layer. Full rules: 00-SCOPE.md.
Coverage draws from public roadmaps (backend, architecture, system design, APIs, DevOps/DevSecOps, data platforms, performance, security literacy, interviews, …)—filtered to transferable ideas. See 00-ATTRIBUTION.md.
Where examples appear, they illustrate the same idea across runtimes (Go, Java, C#, Python, Ruby, Rust, Node, SQL, bash, …)—not a curriculum for one stack.
Folders are numbered in recommended study order. Each phase prepares you for the next: finish a folder’s notes in file order before moving on.
| Phase | Folders | You leave ready to… |
|---|---|---|
| 1 — Build services | 01 → 06 | Ship HTTP APIs with solid data stores |
| 2 — How machines & networks work | 07 → 10 | Reason about processes, packets, complexity |
| 3 — Craft APIs & code | 11 → 13 | Design clean contracts and secure endpoints |
| 4 — Scale systems | 14 → 16 | Design for load, structure, and speed |
| 5 — Run in production | 17 → 21 | Operate Linux → containers → clusters → delivery/security |
| 6 — Professional practice | 22 → 25 | Review code, cyber/network literacy, then interview |
- Append-only for new top-level tracks: add
26-…,27-…(do not renumber existing folders after publish). - Keep the slug after the number stable (
14-system-designstays that name). - Put new notes at the end of an existing folder (
30-…md) unless they must sit earlier for prerequisites—then renumber only inside that folder. - Update this README table when you add a folder.
| # | Folder | Focus |
|---|---|---|
| 01 | 01-core-backend/ |
HTTP → internet → API styles → concurrency → auth → authZ → structure → jobs → caching → observability → security → testing → Git → languages (comparative) |
| 02 | 02-databases/ |
Schema, relationships, SQL/NoSQL/CAP, indexes, ORMs/migrations, specialized stores |
| 03 | 03-sql/ |
SQL DML/DDL, aggregates, joins, CTEs, transactions, EXPLAIN, windows, DB security |
| 04 | 04-postgresql/ |
Postgres as a common backend platform (types, MVCC, indexes, pooling, replication) |
| 05 | 05-redis/ |
Redis structures, streams, persistence, cache/session/rate-limit patterns |
| 06 | 06-mongodb/ |
Document modeling, queries, aggregation, scale, security |
| 07 | 07-operating-systems/ |
Processes, threads, scheduling, memory/sync, CPU cache |
| 08 | 08-networking/ |
Stack, TCP/UDP, DNS/failure, protocols, LBs/gateways, web servers, realtime |
| 09 | 09-algorithms/ |
Complexity, structures, search/sort/graphs, LRU, techniques, interview patterns |
| 10 | 10-computer-science/ |
CS map for backends, encodings/endianness, B-trees/tries, P/NP awareness |
| 11 | 11-software-design/ |
Clean code, OOP/composition, principles, GoF, coupling/cohesion, enterprise patterns |
| 12 | 12-api-design/ |
Resources/URIs, versioning, pagination, errors, caching headers, authZ models, webhooks, contracts |
| 13 | 13-api-security/ |
Auth hardening, JWT/OAuth, TLS/throttle, input/BOLA, endpoint hygiene, security CI |
| 14 | 14-system-design/ |
Scale, HA, cloud, storage, sharding, async, resilience, brokers, CQRS/sagas, gateways |
| 15 | 15-architecture/ |
Decisions, ADRs, DDD, hexagonal, integrations, cloud patterns, IaC, PKI, mesh, data platforms |
| 16 | 16-backend-performance/ |
Caching, DB perf, payloads, async, LB/scaling, code+network tuning, load tests |
| 17 | 17-linux/ |
Filesystem, shell, processes, systemd, disks/logs, networking tools, troubleshooting |
| 18 | 18-docker/ |
Containers vs VMs, images/Dockerfiles, volumes, networking, Compose, DevEx/CI |
| 19 | 19-kubernetes/ |
Workloads, Services/Ingress, config/probes, HPA, RBAC/netpol, rollouts/Helm/GitOps |
| 20 | 20-devops/ |
Hosts/SSH, edge/TLS, cloud/serverless, config/secrets, observability, GitOps, CI tooling |
| 21 | 21-devsecops/ |
Shift-left, crypto, secure coding, threat modeling, supply chain, IAM, IR, compliance |
| 22 | 22-code-review/ |
Pyramid, automation, author/reviewer practices, PR & API checklists |
| 23 | 23-cyber-security/ |
SOC literacy, vulns/hardening, threat awareness, ATT&CK/Kill Chain, enterprise auth |
| 24 | 24-network-engineering/ |
CIDR/NAT, VLAN/routing literacy, firewalls/VPN/VPC, app-side troubleshooting |
| 25 | 25-interviews/ |
Hiring stages, impact signaling, system-design Q&A, REST API Q&A (after the depth above) |
- Language/framework curricula (PHP, Laravel, Node.js, Django, Spring Boot, NestJS, …)—use a stack-specific repo
- Frontend UI tracks (React/Vue, microfrontends, etc.)
- Heavy enterprise EA frameworks / ERP products (TOGAF deep-dives, SAP, Dynamics, …)
- Generic project-management certifications (PMI, Prince2, …) as standalone tracks
- Puzzle-heavy CS tracks (N-Queens, full UML catalogs) unless needed for interviews
- Full cyber career tracks (CTFs, OSCP/CEH paths, offensive tooling, deep forensics/RE)
- Full network-engineer careers (CCNA labs, wireless site surveys, deep BGP/MPLS ops)
- Humans & agents: read
00-SCOPE.mdbefore adding notes - CI:
.github/workflows/scope-guard.ymlrejects stack-specific folder/path patterns
See 00-ATTRIBUTION.md.