https://andergrove.com/ Fast, private browser tools and short writing about building software. en-us Sat, 25 Jul 2026 00:00:00 GMT https://andergrove.com/posts/ssh-key-types-ed25519-vs-rsa/ https://andergrove.com/posts/ssh-key-types-ed25519-vs-rsa/ Sat, 25 Jul 2026 00:00:00 GMT Why ssh-keygen -t ed25519 is the right default, how Ed25519, ECDSA and RSA compare, what quantum computing really changes, and using one key for Git and SFTP. https://andergrove.com/posts/uuid-randomness-and-entropy/ https://andergrove.com/posts/uuid-randomness-and-entropy/ Sat, 25 Jul 2026 00:00:00 GMT A v4 UUID carries 122 bits of randomness; a v7 carries 74. How each is built, where each is used, and why randomness and entropy are not the same thing. https://andergrove.com/posts/how-to-choose-a-web-framework/ https://andergrove.com/posts/how-to-choose-a-web-framework/ Wed, 22 Jul 2026 00:00:00 GMT A decision framework for picking a web framework: the four questions that actually narrow the field, and why team familiarity beats benchmarks. https://andergrove.com/posts/how-to-write-an-invoice/ https://andergrove.com/posts/how-to-write-an-invoice/ Wed, 22 Jul 2026 00:00:00 GMT The nine things every invoice needs, how to number invoices properly, what Net 30 means, and the wording changes that measurably speed up payment. https://andergrove.com/posts/what-is-a-heic-file/ https://andergrove.com/posts/what-is-a-heic-file/ Wed, 22 Jul 2026 00:00:00 GMT HEIC is the iPhone's default photo format — half the size of JPEG at the same quality, but it won't open everywhere. Why Apple uses it, and how to get JPGs. https://andergrove.com/posts/are-online-pdf-tools-safe/ https://andergrove.com/posts/are-online-pdf-tools-safe/ Wed, 22 Jul 2026 00:00:00 GMT When you upload a PDF to a free online tool, where does it actually go and how long does it live there? The real risks, and the browser-only alternative. https://andergrove.com/posts/cron-syntax-cheatsheet/ https://andergrove.com/posts/cron-syntax-cheatsheet/ Mon, 06 Jul 2026 00:00:00 GMT The five cron fields, the schedules everyone actually needs — every 5 minutes, daily at midnight, weekdays at 9 — and the day-of-week trap. https://andergrove.com/posts/sql-formatting-style-guide/ https://andergrove.com/posts/sql-formatting-style-guide/ Mon, 06 Jul 2026 00:00:00 GMT Keyword casing, leading vs. trailing commas, indentation that shows query structure, and JOIN/CTE layout — the SQL rules that make queries reviewable. https://andergrove.com/posts/how-to-unscramble-words/ https://andergrove.com/posts/how-to-unscramble-words/ Mon, 06 Jul 2026 00:00:00 GMT Anagram techniques that actually work: alphagrams, prefix/suffix chunking, and the letter math behind Scrabble, Wordle and newspaper jumbles. https://andergrove.com/posts/average-reaction-time-benchmarks/ https://andergrove.com/posts/average-reaction-time-benchmarks/ Mon, 06 Jul 2026 00:00:00 GMT The average human reaction time is about 250 ms to a visual stimulus. How that shifts with age, hardware and sound vs. sight — and how to test yours. https://andergrove.com/posts/spf-dkim-dmarc-explained/ https://andergrove.com/posts/spf-dkim-dmarc-explained/ Mon, 06 Jul 2026 00:00:00 GMT What SPF, DKIM and DMARC actually check, how the three DNS records fit together, and the misconfigurations that send legitimate email to spam. https://andergrove.com/posts/chunking-strategies-for-rag/ https://andergrove.com/posts/chunking-strategies-for-rag/ Sun, 05 Jul 2026 00:00:00 GMT Most RAG retrieval failures start at chunking. Fixed-size vs. structure-aware vs. semantic chunking, sensible size and overlap defaults, and how to evaluate. https://andergrove.com/posts/how-qr-codes-work/ https://andergrove.com/posts/how-qr-codes-work/ Sat, 04 Jul 2026 00:00:00 GMT A QR code is a 2D barcode holding text with heavy error correction. How the modules encode data, why a torn or logo'd code still scans, and the quishing risk. https://andergrove.com/posts/common-json-errors-and-how-to-fix-them/ https://andergrove.com/posts/common-json-errors-and-how-to-fix-them/ Wed, 01 Jul 2026 00:00:00 GMT "Unexpected token" tells you something broke, not what. The handful of mistakes behind almost every JSON parse error, with the one-line fix for each. https://andergrove.com/posts/webp-vs-jpeg-vs-png/ https://andergrove.com/posts/webp-vs-jpeg-vs-png/ Mon, 29 Jun 2026 00:00:00 GMT Picking the wrong image format bloats pages and hurts Core Web Vitals. Lossy vs lossless, transparency, when WebP and AVIF win, and what compression saves. https://andergrove.com/posts/css-color-formats-explained/ https://andergrove.com/posts/css-color-formats-explained/ Thu, 25 Jun 2026 00:00:00 GMT #7c3aed, rgb(124 58 237) and hsl(258 83% 58%) are one colour. What each CSS colour format encodes, why HSL is the tweakable one, and where oklch fits. https://andergrove.com/posts/embeddings-and-cosine-similarity-explained/ https://andergrove.com/posts/embeddings-and-cosine-similarity-explained/ Sat, 20 Jun 2026 00:00:00 GMT Embeddings turn text into vectors so machines can compare meaning. What an embedding is, why cosine similarity is the metric, and how semantic search works. https://andergrove.com/posts/how-much-vram-to-run-an-llm/ https://andergrove.com/posts/how-much-vram-to-run-an-llm/ Sun, 14 Jun 2026 00:00:00 GMT Will that model fit on your GPU? Where VRAM goes (weights, the KV cache, overhead), what quantization actually saves, and a sizing table by GPU. https://andergrove.com/posts/how-llm-tokenization-works/ https://andergrove.com/posts/how-llm-tokenization-works/ Mon, 08 Jun 2026 00:00:00 GMT Tokens aren't words, and you're billed per token. How LLM tokenization works, why code and emoji cost more, and how to estimate your API bill before you ship. https://andergrove.com/posts/how-to-read-a-tls-certificate/ https://andergrove.com/posts/how-to-read-a-tls-certificate/ Mon, 01 Jun 2026 00:00:00 GMT A TLS certificate is signed metadata binding a public key to a name. How to read the fields that matter — subject, SAN, issuer, validity — and spot red flags. https://andergrove.com/posts/valorant-to-cs2-sensitivity/ https://andergrove.com/posts/valorant-to-cs2-sensitivity/ Mon, 25 May 2026 00:00:00 GMT Moving from Valorant to CS2? Here's the exact sensitivity conversion, why cm/360 is what really matters, and how to keep the muscle memory you built. https://andergrove.com/posts/what-is-a-good-cps/ https://andergrove.com/posts/what-is-a-good-cps/ Mon, 18 May 2026 00:00:00 GMT What counts as a good CPS (clicks per second)? See click-speed benchmarks by skill level, what affects your score, and proven ways to click faster. https://andergrove.com/posts/how-totp-authenticator-apps-work/ https://andergrove.com/posts/how-totp-authenticator-apps-work/ Sun, 10 May 2026 00:00:00 GMT The 6-digit code isn't sent by the server. How TOTP works: a shared secret, an HMAC of the current time, and why the code rotates every 30 seconds. https://andergrove.com/posts/share-a-password-securely/ https://andergrove.com/posts/share-a-password-securely/ Sat, 02 May 2026 00:00:00 GMT Slacking or emailing a password leaves it in logs forever. How to share one safely without a vault: the two-channel rule, and what never to do. https://andergrove.com/posts/hmac-and-webhook-signature-verification/ https://andergrove.com/posts/hmac-and-webhook-signature-verification/ Fri, 24 Apr 2026 00:00:00 GMT A plain hash of a request body proves nothing. Why webhook verification needs HMAC (a keyed hash), how the flow works, and how to compare signatures safely. https://andergrove.com/posts/how-json-web-tokens-work/ https://andergrove.com/posts/how-json-web-tokens-work/ Thu, 16 Apr 2026 00:00:00 GMT A JWT isn't encrypted, only signed, so anyone can read the payload. How JWTs work, why alg:none is dangerous, and how to validate one safely. https://andergrove.com/posts/debt-snowball-vs-avalanche/ https://andergrove.com/posts/debt-snowball-vs-avalanche/ Tue, 07 Apr 2026 00:00:00 GMT Debt snowball vs. avalanche: the snowball builds momentum, the avalanche saves the most interest. See how each works, the trade-off, and which to pick. https://andergrove.com/posts/uuid-v4-vs-v7-for-database-ids/ https://andergrove.com/posts/uuid-v4-vs-v7-for-database-ids/ Sun, 29 Mar 2026 00:00:00 GMT UUIDv4 is random; UUIDv7 is time-ordered. Why random UUIDs fragment database indexes, how v7 fixes it, and a decision table for primary keys vs auto-increment. https://andergrove.com/posts/uuid-versions-explained/ https://andergrove.com/posts/uuid-versions-explained/ Sun, 22 Mar 2026 00:00:00 GMT UUIDs come in several versions, each for a different job. What v1, v3, v4, v5, v6, v7 and v8 (plus nil and max) are for, and which one to reach for. https://andergrove.com/posts/how-long-to-crack-a-password/ https://andergrove.com/posts/how-long-to-crack-a-password/ Sun, 15 Mar 2026 00:00:00 GMT Crack-time charts oversimplify. The real math of password strength: entropy in bits, guesses per second, why length beats complexity, and how to test yours. https://andergrove.com/posts/practical-regex-cheat-sheet/ https://andergrove.com/posts/practical-regex-cheat-sheet/ Thu, 05 Mar 2026 00:00:00 GMT A task-oriented regex cheat sheet: the building blocks that cover 90% of cases, greedy vs lazy, capture groups, copy-paste recipes, and the ReDoS pitfall. https://andergrove.com/posts/how-compound-interest-works/ https://andergrove.com/posts/how-compound-interest-works/ Tue, 24 Feb 2026 00:00:00 GMT Compound interest means earning interest on your interest. See the formula, a worked example, and why starting a decade earlier can beat saving far more later. https://andergrove.com/posts/unix-timestamps-explained/ https://andergrove.com/posts/unix-timestamps-explained/ Sat, 14 Feb 2026 00:00:00 GMT What a Unix timestamp really is: seconds since 1970 UTC. Seconds vs milliseconds, why you store UTC, the Year 2038 problem, and how to get epoch time anywhere. https://andergrove.com/posts/base64-is-not-encryption/ https://andergrove.com/posts/base64-is-not-encryption/ Wed, 04 Feb 2026 00:00:00 GMT Base64 is reversible encoding, not encryption: no key, no secrecy. How it works (3 bytes to 4 chars), why it exists, the 33% size cost, and what to use instead. https://andergrove.com/posts/sha-256-explained/ https://andergrove.com/posts/sha-256-explained/ Sat, 24 Jan 2026 00:00:00 GMT SHA-256 turns any data into a fixed 64-character fingerprint. A plain-English look at what a hash is, what SHA-256 is used for, and why you can't reverse it. https://andergrove.com/posts/hello-world/ https://andergrove.com/posts/hello-world/ Sun, 11 Jan 2026 00:00:00 GMT Why Andergrove Software exists, and how this lean static site is built and maintained. https://andergrove.com/posts/datapower-mgmt-apis/ https://andergrove.com/posts/datapower-mgmt-apis/ Sun, 07 May 2023 00:00:00 GMT A practical guide to the IBM DataPower Gateway REST management API: structure, key resources, and curl examples for reading and updating configuration. https://andergrove.com/posts/datapower-docker/ https://andergrove.com/posts/datapower-docker/ Thu, 02 Mar 2023 00:00:00 GMT How to run IBM DataPower Gateway locally as a free Docker service for development: setup, the docker run command explained, and enabling the Web UI. https://andergrove.com/posts/introduction/ https://andergrove.com/posts/introduction/ Mon, 08 Jun 2020 00:00:00 GMT Andergrove Software is a software services company from Canberra, Australia, run by Chris Hare — an introduction to the blog.