Keep ownership visible.
Choose a container →Separate an owning sequence from a borrowed view, then check the lifetime and invalidation contract.
Programming courses & practice
Learn to code.
Build projects.
Work through lessons, coding exercises and projects in C++, Python, SQL, Git, Bash and Lua.
basics / is_even.cppC++
1// Return true when n is even.
2bool is_even(unsigned n) {
3 return n % 2 == 0;
4}
THE PRACTICE LOOP
- 01 Learn the idea
- 02 Check your understanding
- 03 Find and fix a bug
- 04 Complete the missing pieces
- 05 Build a working solution
Lessons, exercises and projects
SEE THE CONTRACT
Make the idea visible before changing the code.
Follow the rows.
Explore the join →Move the same predicate between ON and WHERE and inspect the rows that remain.
Recover from evidence.
Inspect a recovery route →Distinguish stored objects, reference names and working edits before deciding what can be recovered.
NEW TO PROGRAMMING?
Start from zero.
Never written a program? Pick a language and begin here. Each of these courses opens with six short lessons that take you from printing one line to a complete interactive program: output, variables, input, decisions, loops and functions. If you have no preference, choose Python.
CHOOSE A STARTING POINT
Choose a programming course.
Start with the fundamentals, or pick the tool you want to get better at. Each course shows what to learn first. Python, SQL, Git, Bash and Lua have their own learning sequences.
C++foundations.cpp
Modern C++ & systems programming
Start from zero with your first C++ programs, then learn values, ownership and generic code and apply them to containers, algorithms, concurrency and native systems.
Start learning Lessons & practice
Pyexperiments.py
Python & empirical ML
Start from zero with your first Python programs, then learn objects, functions and reliable data handling and work toward numerical experiments, NumPy, PyTorch and empirical evaluation.
Start learning Lessons & practice
SQLqueries.sql
SQL & relational data
Query real tables and reason about NULLs, joins, grouping, windows, transactions and indexes with runnable SQLite exercises.
Start learning Lessons & practice
gitworkflow.git
Git & collaboration
Work with real repository history: staging, branches, conflicts, remotes, rebase, recovery, worktrees and bisect.
Start learning Lessons & practice
$_scripts.sh
Bash & shell scripting
Start from zero with your first scripts, then make arguments, quoting, streams, pipelines, files and processes work together in dependable shell programs.
Start learning Lessons & practice
Luafunctions.lua
Lua programming
Start from zero with your first Lua programs, then learn values, tables, functions and modules before exploring metatables, iterators, coroutines and resource cleanup.
Start learning Lessons & practice
Make the bits make sense. Learn binary, hexadecimal, one’s complement and two’s complement, with diagrams and practice.
Number foundations →BUILD ON THE FUNDAMENTALS
Languages, data and dependable services.
Go further with Go or JavaScript, or bring your Python and SQL foundations into focused courses. Every course names its prerequisites and ends with a graded project.
Py2 units
HTTP, JSON & API fundamentals
Understand HTTP exchanges and build deterministic URL, JSON, pagination and retry-policy tools over supplied offline responses.
Explore course 7 lessons
Py2 units
Practical Python classes & composition
Design small Python programs with real classes, explicit ownership, stable interfaces and dependable failure behavior.
Explore course 7 lessons
Py3 units
Functional Python foundations
Extend Python functions and iterators into reusable, deterministic data transformations.
Explore course 8 lessons
Py3 units
Cleaning real-world data with Python
Turn messy CSV and JSON into validated records, safe joins and an auditable sales report using Python's standard library.
Explore course 7 lessons
Py3 units
HTML, URLs & parsing
Parse local HTML, resolve and classify URL references, and produce deterministic link reports in Python.
Explore course 7 lessons
Go4 units
Go programming
Go from a first program: a starter unit for complete beginners, then typed values and shared slices through explicit errors to a deterministic JSON log-summary capstone.
Explore course 13 lessons
JS4 units
JavaScript for backend work
An independent Node.js language course that starts from zero, from a first program and explicit values to a tested local data CLI.
Explore course 14 lessons
Py3 units
From Linux processes to containers
Package and review a tiny Python service through processes, images, build inputs, argv, ports, configuration, storage and lifecycle. Graded work uses honest offline fixtures.
Explore course 8 lessons
SQL3 units
Relational database design
Design durable relational schemas with native SQLite keys, dependencies, integrity, migrations and order-level reports.
Explore course 7 lessons
Py3 units
Web application security foundations
Reason about request, identity, data and output boundaries with deterministic Python policy fixtures and real in-memory SQLite.
Explore course 7 lessons
Py3 units
Logs, metrics & debugging services
Investigate structured logs, metric support and trace fixtures; write a reproducible report that separates observations, hypotheses and limits.
Explore course 7 lessons
Py3 units
Queues, retries & reliable background work
Build deterministic Python models of bounded work admission, delivery ownership, retry budgets and idempotent effects, then integrate a restartable job-state simulation.
Explore course 7 lessons
Py3 units
Search your own documents
Build and evaluate a local Python search engine: stable document IDs, Unicode tokens, inverted indexes, ranked results and retrieval metrics.
Explore course 7 lessons
Py3 units
AI tool calling foundations
Build a deterministic Python tool-calling simulation with typed arguments, explicit permissions, structured results and a bounded feedback loop.
Explore course 7 lessons
Py3 units
Your first Python game loop
Build a playable catch-the-ball game: pure state updates, input, elapsed time, Pygame shapes, scoring and restart.
Explore course 7 lessons
Py3 units
Visual graph traversal in Python
Animate breadth-first and depth-first search on a grid, reconstruct parent paths and export a replayable trace.
Explore course 7 lessons
Py3 units
A real API client
Build a bounded Python CLI client against a bundled loopback API: validated pages, retries, cancellation and a deterministic report.
Explore course 7 lessons
Py3 units
Publish a page from Markdown
Build a small documented Markdown parser and publish a styled single HTML page with explicit escaping, safe links and useful diagnostics.
Explore course 7 lessons
SQL3 units
From SQL results to useful dashboards
Define metrics at the right grain, reconcile native SQL results and publish an interactive sales-report snapshot with honest charts.
Explore course 6 lessons
Go3 units
Build your first HTTP service
Build a standard-library Go notes API with explicit server configuration, bounded JSON, deliberate routes, repository boundaries and handler tests.
Explore course 7 lessons
Go3 units
Cryptography for application developers
Use standard Go primitives to distinguish byte encodings, checksums, authentication, authenticated encryption and password-storage requirements.
Explore course 7 lessons
Go3 units
Instrument a tiny service
Connect a running Go notes service to structured logs, server-owned request IDs, bounded counters and honest latency distributions.
Explore course 7 lessons
Py3 units
Working effectively with coding agents
Specify a small bug fix, bound context and tools, review proposed patches and independently verify the final code with a replayable Python/Git lab.
Explore course 7 lessons
Py3 units
Cloud infrastructure fundamentals
Map a tiny API onto compute, network, identity and storage; validate an explained local infrastructure plan before provisioning.
Explore course 7 lessons
TS3 units
TypeScript foundations
Add explicit contracts to JavaScript, narrow unknown data and migrate the existing JSON report CLI with real compiler diagnostics and runtime checks.
Explore course 6 lessons
Go3 units
From SQLite to PostgreSQL
Move a small notes application from an actual SQLite fixture to an owned local PostgreSQL cluster, with versioned migrations, parameters, transactions and full-row reconciliation.
Explore course 7 lessons
Py3 units
From Python records to DataFrames
Translate records into actual Pandas operations with deliberate dtypes, missing-value policy, grouping grain and validated joins; reconcile the existing cleaning report.
Explore course 7 lessons
PUT THE PIECES TO WORK
Explore projects and learning paths.
Try an interactive tool
Choose a C++ container, investigate Git recovery or follow real rows through a SQL join.
Follow a practical learning path
Connect courses around backend, systems, embedded or data work, with preparation and a concrete outcome.
Build a weekly practice habit
Trace a small program, choose an explanation and use the feedback to decide what to practice next.
Take a contract into a project. Preview an original C++/Linux artifact publisher, with starter code and tests.
Project preview →FROM PROGRAM TO PHYSICAL PROJECT
Make something you can put on your desk.
Guided lessons, downloadable code and desktop logic tests. Bring compatible parts you own, or explore the optional equipment cards when you are ready to build.
C++ / GUIDED BUILD
Build an Arduino distance beacon
Make a tabletop proximity display with an ultrasonic sensor, three LEDs, bounded reads and testable C++ state transitions.
Explore the course →6 lessons
C++ / GUIDED BUILD
Build a CoreS3 motion counter
Use the built-in IMU and screen to count distinct motion bursts, with gravity rejection, rearming and a cooldown.
Explore the course →6 lessons
PYTHON / GUIDED BUILD
Build a camera-powered QR journal
Turn a Raspberry Pi camera into a local marker journal. Validate labels, suppress repeat scans and keep a useful event log.
Explore the course →6 lessons
PYTHON / GUIDED BUILD
Build a Pico room monitor
Read temperature and humidity, handle missing samples and drive a calm two-LED status display with MicroPython.
Explore the course →6 lessons
MORE THAN READING
Learn with diagrams, exercises and review.
See the moving parts.
Read worked examples, explore diagrams and use videos when another explanation helps. Connect the code to the idea behind it.
Make a working solution.
Answer checks, debug broken code and build in the editor. Test feedback shows what to work on next.
Bring it back later.
Use spaced coding review and flashcards to revisit the decisions: which type, which container, which command, and why.
Try flashcards →SYSTEMS PROGRAMMING TOPICS
Explore operating systems and hardware.
Move from language fundamentals to the systems they run on.
Before you start
What does CodeRigor cost?
CodeRigor’s courses, lessons, exercises and flashcards are currently available without charge. Optional courses, tutoring and equipment from other providers may cost money. Affiliate offers identify the provider and include a referral disclosure.
Do I need to learn C++ before Python or SQL?
No. Python, SQL, Git, Bash and Lua have independent sequences. Inside each sequence, prerequisite links help you find the right order.
Where should a complete beginner start?
Start with the first unit of a language course, “Start here: your first programs”, which assumes no programming experience at all: Python, JavaScript, C++, Go, Bash or Lua. If you have no preference, choose Python. Six short lessons take you from printing a line of text to a complete interactive program, and the next unit of the same course continues from there. If the bits are unfamiliar, keep the binary and hex lessons alongside your study.