David Coimbra — WritingWhat I learn in class, at work and by breaking things.https://davidcoimbra.devenMon, 21 Sep 2026 00:00:00 GMTModularity in practice: naming the cohesion, then splitting two real systemshttps://davidcoimbra.dev/blog/modularity-in-practicehttps://davidcoimbra.dev/blog/modularity-in-practiceA cohesion quiz with real examples, then two decomposition exercises: a condominium payments workflow and a padel club booking system with an AI agent.Mon, 21 Sep 2026 00:00:00 GMTarticlesoftware-architecturesoftware-designmodularityhi@davidcoimbra.dev (David Coimbra)Arithmetic expressions: terms, derivations and a first interpreterhttps://davidcoimbra.dev/blog/arithmetic-expressionshttps://davidcoimbra.dev/blog/arithmetic-expressionsExercises on the arithmetic expressions of TAPL chapter 3: building terms, proving what is and isn't a term, evaluation rules, and a Haskell interpreter.Tue, 15 Sep 2026 00:00:00 GMTarticleprogramming-languagestypessemanticshaskellhi@davidcoimbra.dev (David Coimbra)Reading programming language papers: the notation, from sets to inference ruleshttps://davidcoimbra.dev/blog/pl-notation-primerhttps://davidcoimbra.dev/blog/pl-notation-primerA primer on the maths behind programming language theory: sets, grammars, metavariables, inductive definitions, inference rules, axioms, derivations and evaluation.Tue, 15 Sep 2026 00:00:00 GMTarticleprogramming-languagestypessemanticslogichi@davidcoimbra.dev (David Coimbra)From modules to agents: how architecture evolved, and how to measure modularityhttps://davidcoimbra.dev/blog/modularity-and-cohesionhttps://davidcoimbra.dev/blog/modularity-and-cohesionA short history of software architecture, from Dijkstra's layers to cloud, containers and LLM agents, then modularity vs granularity, cohesion types and the LCOM metric.Mon, 14 Sep 2026 00:00:00 GMTarticlesoftware-architecturesoftware-designmodularityhi@davidcoimbra.dev (David Coimbra)What a software architect does: architecture vs design, the three laws and eight expectationshttps://davidcoimbra.dev/blog/software-architect-laws-and-expectationshttps://davidcoimbra.dev/blog/software-architect-laws-and-expectationsArchitecture vs design, the three laws of software architecture, architecture characteristics, recording decisions, and what is expected of an architect.Mon, 14 Sep 2026 00:00:00 GMTarticlesoftware-architecturesoftware-designcareerhi@davidcoimbra.dev (David Coimbra)One call instead of N: 90% fewer search requestshttps://davidcoimbra.dev/blog/car-and-classic-filtershttps://davidcoimbra.dev/blog/car-and-classic-filtersAt Car & Classic, the search filter modal fired one request per filter group. One call, and a front end rebuilt around it, cut the modal’s requests by about 90%.Tue, 01 Sep 2026 00:00:00 GMTarticlecase-studyperformancearchitecturebackendhi@davidcoimbra.dev (David Coimbra)What the homepage renders first: 125 KB to 43 KBhttps://davidcoimbra.dev/blog/homepage-payloadhttps://davidcoimbra.dev/blog/homepage-payloadA section-by-section audit of the Car & Classic homepage decided what to server-render, what to load later and what to cap, cutting page data by two thirds.Fri, 20 Feb 2026 00:00:00 GMTarticlecase-studyperformancefrontendseohi@davidcoimbra.dev (David Coimbra)4,000 photos that load only when you want them: a virtual carousel in Vuehttps://davidcoimbra.dev/blog/virtual-photo-carouselhttps://davidcoimbra.dev/blog/virtual-photo-carouselHow Car & Classic listing cards show 100+ photos each, Airbnb-style, without janking the homepage: intent-based loading, paged photos, a virtual track.Wed, 18 Feb 2026 00:00:00 GMTarticlecase-studyperformancefrontendvuehi@davidcoimbra.dev (David Coimbra)My first Inertia PR: making usePage() a singletonhttps://davidcoimbra.dev/blog/inertia-usepage-singletonhttps://davidcoimbra.dev/blog/inertia-usepage-singletonusePage() in Inertia built a new reactive object with 13 computed properties on every call. Turning it into a lazily created singleton removed the waste, and it’s part of Inertia’s 3.x branch.Thu, 12 Feb 2026 00:00:00 GMTarticleopen-sourcevueinertiaperformancehi@davidcoimbra.dev (David Coimbra)Form inputs for a whole company: one component per field, built on composableshttps://davidcoimbra.dev/blog/form-inputshttps://davidcoimbra.dev/blog/form-inputsWhy I replaced a wrapper-based form pattern at Car & Classic with self-contained inputs built on small composables, and how the select typing contract works.Tue, 05 Aug 2025 00:00:00 GMTarticlecase-studyfrontendvuearchitectureaccessibilityhi@davidcoimbra.dev (David Coimbra)11 seconds to 500 ms: making a healthcare platform faster by adding endpointshttps://davidcoimbra.dev/blog/healthcare-platform-endpointshttps://davidcoimbra.dev/blog/healthcare-platform-endpointsWebMD Ignite case study: 30 overloaded endpoints became 46 focused ones, and screens, indexes and caching followed. Responses went from 3–11 s to 150–500 ms.Tue, 10 Dec 2024 00:00:00 GMTarticlecase-studyperformancearchitecturebackendhi@davidcoimbra.dev (David Coimbra)