Notes on building.
Guides on mobile apps, web platforms and AI products. Cost breakdowns, stack comparisons and how we ship.
WhatsApp Service Messages Now Cost Money: Rebudget
Since October 1, 2026, Meta bills service messages past the first 1,000 a month per phone number, and utility messages inside the 24-hour window are billable too. Here is how to find your exposure and cut it.
Cost & planning · Oct 25, 2026 · 10 min read
Mistral Large 4 Preview: Use the API or Wait for Weights
Mistral opened Large 4 as a public preview on October 6 and promised open weights before the end of the month. Here is how to decide between calling the preview API, waiting for the weights, or ignoring it.
AI & strategy · Oct 24, 2026 · 11 min read
Android 17 and targetSdk 37: What Founders Need to Plan
Android 17 shipped in June and targeting API 37 changes how your app behaves on tablets and foldables. Here is what breaks, what the upgrade costs, and how it connects to Google Play's October 28 contacts and location rules.
How to build · Oct 24, 2026 · 9 min read
GPT-6 Luna vs Claude Haiku 5.5: Which Cheap Model Wins
OpenAI and Anthropic now sell their small models at the same list price. That makes price the least useful way to choose. Here is how to decide on workload, long-context rules and switching cost.
AI & strategy · Oct 23, 2026 · 10 min read
What It Costs to Take Over an Abandoned App Codebase
Your agency went quiet, your freelancer moved on, or your CTO left with the passwords. Here is what a takeover costs, what to secure in week one, and when to stop patching and rebuild.
Cost & planning · Oct 22, 2026 · 11 min read
Meta Muse Wonder API: Should Your Startup Switch?
Meta shipped its first frontier-tier model to a self-serve API on October 12. Here is what the preview gives you, what it hides, and a two-week test that tells you whether to switch.
Technology · Oct 21, 2026 · 11 min read
Mercury 3 and Diffusion LLMs: Where Speed Pays Off
Inception Labs released Mercury 3 on October 19, a diffusion language model priced well below the frontier. Here is where a fast, cheap tier belongs in your app and where it does not.
How to build · Oct 21, 2026 · 9 min read
Gemini 4 Argon Pricing Doubles December 1: Budget for It
Google's introductory rate for Gemini 4 Argon ends soon, and the list price doubles after it. Here is how to model your unit cost at the post-December price, cap the downside and decide whether to stay.
Cost & planning · Oct 20, 2026 · 10 min read
Open-Weight Frontier Models: Self-Host or Pay the API?
A wave of open-weight models landed in mid-October 2026, and every founder with an API bill is asking whether to switch. For most startups the answer is still an API plus routing, with a few clear exceptions.
AI & strategy · Oct 20, 2026 · 12 min read
Pricing an AI Feature: Credits, Seats or Usage?
Every AI feature has a variable cost that your old seat-based plan never had to carry. Here is how to choose between seats, usage, credits and outcome pricing without wrecking your gross margin.
AI & strategy · Oct 19, 2026 · 11 min read
Staged Rollouts for Mobile Apps: A Release Playbook
App store review is not a safety net, and a bad release can reach every user in hours. This playbook covers rollout percentages, crash thresholds, halt rules and rollback options for iOS and Android.
How to build · Oct 19, 2026 · 11 min read
Apple's Oct 16 Review Rules: AI Content and Hidden Features
Apple updated its App Review Guidelines on October 16, 2026, tightening Guideline 1.2 on AI-generated intimate imagery and adding Guideline 2.5.19 on hidden or dormant features. Here is what changed, who is exposed, and what to audit this week.
How to build · Oct 18, 2026 · 10 min read