The Core Technical T-Shape
A good full-stack developer has broad knowledge across the stack, but they should be deeply specialized (the vertical bar of the “T”) in at least one area.
Frontend Proficiency: Deep understanding of modern JavaScript/TypeScript and at least one major framework (React, Vue, or Angular). They should understand state management, responsive CSS, and web performance (like minimizing bundle sizes and rendering optimization).
Backend & API Design: Strong command of an enterprise-grade backend language (Node.js, Python, Go, Java, or .NET). More importantly, they must know how to design clean, scalable RESTful or GraphQL APIs.
Database Management: Proficiency in both relational (SQL like PostgreSQL, MySQL) and non-relational (NoSQL like MongoDB) databases. They should know how to write efficient queries, design schemas, and handle basic indexing.
Architecture & Systems Thinking
Junior developers write features; senior developers build systems. Look for a candidate who understands:
Cloud & DevOps Basics: They don’t need to be a dedicated DevOps engineer, but they should know how to navigate AWS, GCP, or Azure, manage Docker containers, and understand CI/CD deployment pipelines.
System Design: An understanding of caching strategies (Redis), authentication flows (OAuth, JWT), and architectural patterns (microservices vs. monoliths).