How JSON Web Tokens Work Without Hiding Their Contents
JWTs package claims into portable, signed tokens. Their value comes from verifiable integrity, not from keeping the payload secret.
Read article / 8 min read RegexHow Regular Expressions Read Text
Regular expressions describe text patterns through literals, classes, repetition, boundaries, and groups. Learning how those parts cooperate makes regex far less mysterious.
Read article / 8 min read URLHow URLs Turn Text Into Reliable Web Addresses
A URL is more than a link. Its scheme, authority, path, query, fragment, and encoding rules form a compact instruction for locating and identifying resources.
Read article / 8 min read UUIDHow UUIDs Create Identifiers Without Central Coordination
UUIDs let independent systems create identifiers with an extremely low collision risk, changing how records can be created, merged, and shared.
Read article / 8 min read TimeUnix Time and the Problem of Representing “Now”
Unix timestamps provide a simple shared timeline, but precision, leap seconds, clock quality, and interpretation still require deliberate choices.
Read article / 8 min read HashWhat Cryptographic Hashes Prove, and What They Do Not
A hash condenses data into a fixed-size fingerprint. That fingerprint supports integrity checks and signatures, but it is not encryption or proof of trust by itself.
Read article / 8 min read Base64What Is Base64 Encoding, and Why Does Software Still Use It?
Base64 turns binary bytes into portable text. Understanding why it exists makes its odd-looking output, padding, overhead, and limitations much easier to reason about.
Read article / 8 min read HTMLWhy HTML Entities Exist
HTML entities let documents represent characters that would otherwise be mistaken for markup, but correct escaping depends on context.
Read article / 8 min read JSONWhy JSON Became the Language of Web APIs
JSON won because it made structured data easy to read, generate, and move between unrelated systems. Its success also created conventions developers now take for granted.
Read article / 8 min read RegexAvoiding Catastrophic Regex Backtracking
Some regex patterns explore an enormous number of matching paths on hostile input. Understanding ambiguity prevents performance bugs and denial-of-service risks.
Read article / 8 min read Base64Base64 vs Base64URL: Similar Encodings With Different Jobs
Base64URL changes only a few characters, yet those changes matter whenever encoded data appears in URLs, cookies, filenames, or JWTs.
Read article / 8 min read HashChecksums, Hashes, and Digital Signatures: Choosing the Right Integrity Tool
Checksums detect accidents, hashes fingerprint bytes, MACs authenticate shared-secret messages, and signatures connect integrity to a private key.
Read article / 8 min read UUIDChoosing the Right UUID Version
Random, time-ordered, and name-based UUIDs provide different guarantees. Selecting a version should follow system requirements rather than habit.
Read article / 8 min read JSONDebugging Invalid JSON in Real Applications
Invalid JSON is often a symptom of a broken boundary, unexpected encoding, or incorrect assumptions rather than a simple missing comma.
Read article / 8 min read URLDesigning Clean, Stable, and Shareable URLs
Good URLs communicate hierarchy, preserve meaning over time, avoid accidental state, and remain useful outside the application that created them.
Read article / 8 min read JSONDesigning JSON APIs That Survive Change
A durable JSON API depends less on clever payloads than on predictable naming, explicit types, careful compatibility, and useful errors.
Read article / 9 min read TimeDesigning Reliable Time-Based Systems
Expiration, scheduling, retries, and event ordering need explicit clock semantics, idempotency, and tolerance for delayed or duplicated work.
Read article / 8 min read HTMLHTML Encoding, Decoding, and Data Quality
Entity bugs often reveal unclear ownership between storage, APIs, editors, and templates. A consistent data model prevents double encoding and corrupted text.
Read article / 8 min read JWTJWT Security Mistakes and How to Avoid Them
Most JWT failures come from permissive verification, exposed bearer tokens, weak lifecycle decisions, and misplaced trust in readable claims.
Read article / 9 min read JWTJWT vs Sessions: Choosing an Authentication Model
JWTs and server-side sessions solve overlapping problems with different trade-offs in revocation, scale, privacy, and operational complexity.
Read article / 8 min read HTMLPreventing XSS With Contextual Output Encoding
Cross-site scripting prevention depends on keeping untrusted data out of executable contexts and encoding for the exact place where data is inserted.
Read article / 9 min read TimeTimezones, Daylight Saving, and Calendar Surprises
Local time is a political calendar rule, not a fixed numeric offset. Reliable scheduling requires preserving timezone identity and handling gaps and overlaps.
Read article / 8 min read URLURL Encoding Mistakes That Break Real Applications
Double encoding, confused plus signs, unsafe redirects, and inconsistent parsing turn simple links into difficult production bugs.
Read article / 8 min read UUIDUUID Mistakes in Databases and APIs
UUIDs remove central allocation, but careless storage, validation, indexing, and authorization can turn convenient identifiers into avoidable problems.
Read article / 8 min read Base64When Not to Use Base64: Performance, Security, and Design Trade-offs
Base64 is useful at text-only boundaries, but using it everywhere creates larger payloads, extra memory work, misleading security, and harder APIs.
Read article / 8 min read HashWhy Passwords Need Special Hashing
Fast hashes protect file integrity but make password guessing cheaper. Password storage needs salts, expensive algorithms, and upgradeable parameters.
Read article / 8 min read RegexWriting Regular Expressions Other Developers Can Maintain
Readable regex depends on narrow responsibility, explicit boundaries, named groups, examples, and tests that explain why the pattern exists.
Read article / 8 min read