Write-ups from the people building itTenant boundaries, idempotent payments, layout shift, mobile clients — the problems we hit building and running Clasify, written up in full.What Does a Web Development Company Actually Do?A web development company builds the data model, the permissions, the payments and the operations behind a site — not only the design. What the work covers, what it excludes, and how to judge one.How to Choose a Web Development Company in EgyptSearch for web development companies in Egypt and you get directories with hundreds of names. Here are the questions that separate a team who can build your project from one who can pitch it.A Layout Shift That Only Exists While the HTML Is Still StreamingOur homepage scored CLS 0.351 while the finished page never moved. The cause was one centring class and a 300 KB streamed document — and why localhost can never show it.Adding a Mobile Client to a Product That Already Has a Web AppParity is a moving target, scope decisions need tests of their own, and a phone outlives both the session and the tenant. Three problems that cost us time — none of them layout.Why Every Permission Check in Our System Lives in One FileA missing call is visible in review; a missing role comparison is not. How we centralised authorization for an internal system, and why we log denials rather than grants.You Sent the Charge and the Connection Died. Did It Charge?The hard part of payments is not the card form — it is reconciling with someone else's ledger across crashes, retries and duplicate webhooks. How we designed for exactly-once.Multi-Tenant SaaS Architecture: Where to Put the Tenant BoundaryHow we enforce tenant isolation in a multi-tenant SaaS — a Prisma guard that fails closed in every environment, and the test that stops the allowlist rotting.