Practical field notes
Developer Guides
These guides explain the decisions behind common debugging tasks. They combine standards-based references with repeatable checks you can use before copying tool output into an application, ticket, or production workflow.
Written Around A Real Failure Mode
Each guide starts with a problem developers actually encounter, shows the boundary that causes it, and ends with a verification checklist. The linked tools are demonstrations, not substitutes for the system that will consume the result.
References And Review
Technical claims are checked against standards or platform documentation where an authoritative source exists. Review dates, limitations, and related tools are kept visible so readers can judge how much confidence to place in an example.
How to debug invalid JSON without guessing
Find the first real syntax error, distinguish JSON from JavaScript, and verify the corrected payload.
AuthenticationHow to inspect a JWT without trusting it
Read token claims safely and understand what still must be verified by the receiving application.
Time and dataUnix timestamp troubleshooting
Recognize seconds, milliseconds, timezone display problems, and boundary errors.
EncodingBase64, URL encoding, and the boundary problem
Choose the correct encoding for bytes, URL components, and text without double-encoding data.
Text matchingHow to debug a regular expression
Reduce a failing pattern, inspect capture groups, and account for differences between regex engines.
IntegrityHashes, checksums, and what they prove
Choose a digest for the job, compare exact bytes, and avoid confusing integrity checks with encryption.
Data exchangeMoving data between JSON and CSV
Identify the tabular boundary, preserve types intentionally, and test quoting and missing values.
SchedulingCron schedules and timezone surprises
Read five-field expressions, preview the right instants, and check the scheduler's timezone rules.