Debugging
Also known as: debug
Debugging is the process of finding, understanding, and fixing errors, called bugs, in software or systems.
It involves reproducing the problem, narrowing down its cause using tools such as debuggers, logs, and tests, then fixing it and confirming the fix works. Debugging is a core skill for developers and IT support alike. While fixing bugs can be satisfying, the hardest part is usually finding the root cause rather than just the symptom.
Debugging, explained at three levels
At home
Debugging is like being a detective. You gather clues, test theories, and track down exactly what's causing the problem.
At work
Good debugging skills shorten outages and reduce the time staff spend stuck on broken systems.
At home
A simple debugging method is to change one thing at a time and see if the problem changes. Searching the exact error message online often helps too.
At work
Debuggers let developers pause code, inspect variables, and step through line by line. Logs, traces, and metrics help debug problems in production where pausing isn't possible.
At home
Explaining the problem out loud, called 'rubber duck debugging,' often reveals the answer. In my opinion, it works surprisingly well.
At work
Capture reproducible steps, write a failing test before fixing, look for root causes rather than symptoms, document findings in postmortems, and keep debug features disabled in production.
Real-world examples
At home
Aisha's spreadsheet formula gave wrong totals. She checked each cell step by step and found one number stored as text.
At work
Jerome supports a Regina hospital's scheduling system. By comparing logs before and after an update, he found the setting change that broke appointment reminders.
How it compares
| feature | Debugging | Testing |
|---|---|---|
| Goal | Find and fix the cause | Find whether problems exist |
| When | After a problem appears | Before and during development |
| Tools | Debuggers, logs | Test frameworks |
| Result | A fix | Pass or fail |
Testing reveals bugs. Debugging removes them.
For analysts
When reporting defects, I'd always include steps to reproduce, expected and actual results, and screenshots. It can cut debugging time in half.
History & origin
Engineers used the word 'bug' for technical faults well before computers, including Thomas Edison in the 1870s. In September 1947, operators of the Harvard Mark II computer found a moth trapped in a relay and taped it into their logbook with the note 'first actual case of bug being found,' a story Grace Hopper often told. Interactive debuggers appeared in the 1960s, and tools such as the GNU Debugger (GDB), first released in 1986, became standard. Modern development environments include visual debuggers, and observability tools let teams debug live cloud systems. AI assistants now help explain errors and suggest fixes. In my view, debugging teaches more about how software really works than writing it does.