“Learn the fundamentals so you’ll succeed in your endeavor” This is a common piece of advice people often give. You’ll frequently hear it when asking how to secure your career or how to learn a new technology, etc.
In today’s world, overflowing with knowledge and information. This advice is vague and it leaves us with unanswered questions. What exactly should I learn as fundamentals? How can I be sure I’m learning the right things?
So when someone says “learn the fundamentals”, the right response is:
“Which fundamentals, and how deep, based on what I’m building?”
Physics & Electronics (Atoms, Electrons, Gates, etc.)
Necessary if you’re doing hardware design, building compilers, or working with embedded systems. Not necessary for typical software developers.
Computer Architecture & Operating Systems
This area consists of concepts CPU cycles, memory hierarchy (RAM vs cache), processes, threads, virtual memory, file systems.
This is necessary if you’re into systems programming, performance tuning, or OS development.
Programming Language Theory & Compilers
This is about syntax, parsing, type systems, interpreters vs compilers.
This is necessary if you’re building tools (like linters, and transpilers), designing new languages, or deep into back-end design.
Data Structures & Algorithms
Concepts and implementation of arrays, linked lists, trees, hashmaps, sorting, recursion, time/space complexity.
This is essential for all developers. They underlie everything, from efficient code to debugging performance issues.
Networking Basics
This is about the theory of HTTP, TCP/IP, DNS, client-server model.
This is necessary if you build web apps, mobile apps, APIs, etc. But you don’t need to know TCP flags or OSI model layers deeply unless you’re in DevOps or network engineering.
Databases & Querying
This is about the design of databases, SQL, indexing, normalization, and transactions.
Learning databases is essential for most types of app developers. You can’t avoid data persistence.
Version Control, Build Tools, Deployment
This is about learning Git, CI/CD, testing, and packaging tools.
It is required for modern software development in teams and production settings.
Software Architecture
Software architecture becomes fundamental once you move from building apps that “just work” to systems that are “designed to last.” Architecture is essential at certain points in a developer’s or engineer’s journey. especially when working on large-scale, long-lived, or team-based systems.
Linear Algebra, Statistics, Programming (Python) and ML Theory
The fundamentals required for AI vary depending on the role you’re aiming for.
whether you’re a machine learning engineer, data scientist, AI researcher, ML ops engineer, or even a developer using AI APIs these are the core knowledge areas required for that.
Final thoughts:
My list is limited to few common IT and Computer related fields. There are many more.
When learning fundamentals, you don’t need to “boil the ocean” of computer science. As a practical use, go just deep enough to understand what your tools abstract away. And just go deeper when things break, or performance matters.

A multifaceted professional known for diverse interests and contributions in various fields, including management, technology, education and entrepreneurship. Also the founder of ITPro.lk, bringing a unique perspective and industry knowledge to writing.