📊 Skill Matrix: what you know vs. what to deep dive
Levels: 0 = never used · 1 = know the concept · 2 = can use it with docs · 3 = built something real and can explain the trade-offs · 4 = can debug it in production and teach it Target = what a strong SDE-1/SDE-2 at a top product company shows in interviews and on the job.
How to use this
Fill in Now on W1 day 1. Update it at every phase retro. Anything with a gap ≥ 2 gets extra time in the next phase. Be brutally honest: this matrix is for you, not a recruiter.
| Area | Skill | Now | Target | Where |
|---|---|---|---|---|
| Language | Java (modern, 21/25) | 4 | Java Advanced | |
| Language | Java concurrency / JVM | 3 | Java Advanced · Concurrency | |
| Language | Go | 4 | Go Advanced | |
| Language | Python | 2 | Python Essentials | |
| DSA | Core patterns (arrays → graphs) | 4 | DSA Roadmap (Java) | |
| DSA | DP / advanced graphs | 3 | Pattern Playbook | |
| CS | OS / processes / memory | 3 | Operating Systems | |
| CS | Networking (TCP, HTTP, TLS, DNS) | 3 | Networking | |
| CS | DB internals (indexes, MVCC, isolation) | 3 | Database Internals | |
| Design | LLD / OOP / design patterns | 4 | Low-Level Design & Machine Coding | |
| Design | HLD / system design | 3 | System Design Roadmap | |
| Design | Distributed systems theory | 3 | Distributed Systems | |
| Java stack | Spring Boot | 4 | Spring Core & Boot | |
| Java stack | JPA / Hibernate | 3 | Spring Data & JPA | |
| Java stack | Spring Security / OAuth2 | 3 | Spring Security | |
| Java stack | Spring Cloud / resilience | 3 | Spring Cloud & Microservices | |
| Java stack | Spring AI | 3 | Spring AI | |
| Go stack | Go web services | 4 | Go Backend Development | |
| APIs | REST design | 4 | REST API Design | |
| APIs | gRPC / Protobuf | 3 | gRPC & Protobuf | |
| APIs | GraphQL | 3 | GraphQL | |
| Data | PostgreSQL | 4 | PostgreSQL | |
| Data | Redis | 3 | Redis | |
| Data | Kafka | 3 | Kafka | |
| Data | Data pipelines / CDC | 2 | Data Pipelines | |
| Infra | Docker | 4 | Docker | |
| Infra | Kubernetes | 3 | Kubernetes | |
| Infra | Envoy / gateway / mesh | 2 | Envoy, Gateways & Service Mesh | |
| Infra | AWS | 3 | Cloud (AWS) | |
| Infra | Terraform | 2 | Terraform & IaC | |
| Infra | CI/CD, GitOps | 3 | CI-CD & GitOps | |
| Ops | Observability (OTel) | 3 | Observability | |
| Ops | SRE / performance | 3 | SRE & Reliability | |
| Security | AppSec + auth | 3 | Security Engineering | |
| AI | LLM integration | 4 | LLM Fundamentals | |
| AI | RAG | 3 | RAG | |
| AI | Agents / LangGraph / MCP | 3 | Agents & Workflows · MCP | |
| AI | Evals & LLMOps | 3 | Evals, Guardrails & LLMOps | |
| Frontend | React + TypeScript (+ React Flow) | 2 | Frontend Essentials | |
| Internals | JVM / Go runtime | 3 | JVM Internals · Go Runtime Internals | |
| Internals | Spring / Postgres / Redis / Kafka | 3 | Internals Roadmap | |
| Internals | Containers / K8s / Envoy / network stack | 3 | Internals Roadmap | |
| Internals | LLM inference / vector search | 3 | LLM Inference Internals | |
| Patterns | GoF + concurrency | 4 | GoF Patterns (Java & Go) · Concurrency Patterns | |
| Patterns | Distributed / cloud / AI patterns | 3 | Distributed & Cloud Patterns · AI & Agent Patterns | |
| Thinking | Predict → verify, debugging, trade-offs | 4 | Cognitive Drills | |
| Soft | Design docs / communication | 3 | Design Docs & ADRs | |
| Soft | Behavioral interviews | 4 | Behavioral & STAR |
History
| Date | Phase | Biggest gaps | Actions |
|---|---|---|---|
| 2026-09-28 | Baseline |