https://misbah.co/blog Notes on revenue-critical code, plugin modernization, founder engineering, and products that last. en Mon, 13 Jul 2026 00:00:00 GMT https://misbah.co/blog/cost-cutting-is-motion-not-a-strategy https://misbah.co/blog/cost-cutting-is-motion-not-a-strategy Cutting costs moves the numbers, not the company. The long game goes to people who stay to hold context and balance operators with entrepreneurs. Mon, 13 Jul 2026 00:00:00 GMT https://misbah.co/blog/store-money-as-integer-cents-never-a-float https://misbah.co/blog/store-money-as-integer-cents-never-a-float An opinionated rule for money code: store amounts as integer minor units, never a binary float, and never divide a total to get its parts. Sat, 11 Jul 2026 00:00:00 GMT https://misbah.co/blog/the-refund-path-is-where-i-read-a-codebases-soul https://misbah.co/blog/the-refund-path-is-where-i-read-a-codebases-soul Checkout code is easy. Refunds, proration, and failed webhooks are where I can tell if a payments codebase was built by someone senior. Wed, 08 Jul 2026 00:00:00 GMT https://misbah.co/blog/you-dont-rewrite-a-plugin-with-a-big-install-base https://misbah.co/blog/you-dont-rewrite-a-plugin-with-a-big-install-base How I evolve a WordPress plugin with a large install base without breaking users mid-update: a strangler-fig approach with real PHP and version gates. Wed, 01 Jul 2026 00:00:00 GMT https://misbah.co/blog/the-first-hire-who-touches-your-billing-should-be-boring https://misbah.co/blog/the-first-hire-who-touches-your-billing-should-be-boring The engineer who owns revenue early should reach for idempotency, audit logs, and reconciliation by reflex. How to screen for it and reject the rest. Wed, 24 Jun 2026 00:00:00 GMT https://misbah.co/blog/boring-code-is-a-feature-you-ship-to-your-future-self https://misbah.co/blog/boring-code-is-a-feature-you-ship-to-your-future-self Boring code wins on systems that have to last. Why the durable choice looks unimpressive, how to defend it in review, and when to delete clever code. Wed, 17 Jun 2026 00:00:00 GMT https://misbah.co/blog/six-payments-edge-cases-that-bite-at-2am https://misbah.co/blog/six-payments-edge-cases-that-bite-at-2am Partial refunds, duplicate webhooks, currency rounding, retries, chargebacks, and clock skew: the payments edge cases that page you, with the fix for each. Wed, 10 Jun 2026 00:00:00 GMT https://misbah.co/blog/shipping-a-feature-into-a-five-year-old-plugin https://misbah.co/blog/shipping-a-feature-into-a-five-year-old-plugin Real tactics for shipping into an old WordPress plugin: feature flags, backward-compatible DB migrations, and staged rollouts across a live install base. Wed, 03 Jun 2026 00:00:00 GMT https://misbah.co/blog/three-questions-before-i-write-billing-code https://misbah.co/blog/three-questions-before-i-write-billing-code Three questions to answer before you build billing: what is the source of truth, what happens when this runs twice, and how do we reconstruct it later. Wed, 27 May 2026 00:00:00 GMT https://misbah.co/blog/subscriptions-are-licensing-that-bills-on-time https://misbah.co/blog/subscriptions-are-licensing-that-bills-on-time A subscription is a state machine bolted to a billing clock. Dunning, grace periods, and proration are where it leaks money. Here is how I model each. Wed, 20 May 2026 00:00:00 GMT https://misbah.co/blog/backward-compatible-migrations-on-an-install-base https://misbah.co/blog/backward-compatible-migrations-on-an-install-base The migration rules I hold on a live WordPress install base: additive columns only, no destructive deploys, version gates, and a rollback plan. Wed, 13 May 2026 00:00:00 GMT https://misbah.co/blog/build-vs-buy-for-billing https://misbah.co/blog/build-vs-buy-for-billing For most early products a hosted processor like Stripe is enough. It stops at four: global tax, usage-based pricing, marketplaces, and provider limits. Wed, 06 May 2026 00:00:00 GMT https://misbah.co/blog/why-i-run-uptime-checks-at-the-edge https://misbah.co/blog/why-i-run-uptime-checks-at-the-edge A single VPS in one region tells you about its own path, not your users'. Here is how I built edge uptime checks on Cloudflare Workers and why. Wed, 29 Apr 2026 00:00:00 GMT https://misbah.co/blog/supporting-a-plugin-across-wordpress-versions https://misbah.co/blog/supporting-a-plugin-across-wordpress-versions A compatibility strategy for WordPress and PHP versions you don't control: function_exists and capability checks, graceful degradation, a support matrix. Wed, 22 Apr 2026 00:00:00 GMT https://misbah.co/blog/authentication-mistakes-in-early-products https://misbah.co/blog/authentication-mistakes-in-early-products The same auth bugs show up in early products: session fixation, weak hashing, no rate limiting, tokens in the wrong place. Here is the fix for each. Wed, 15 Apr 2026 00:00:00 GMT