https://sparkfile.co Find what to build. Build it on Claude. en-us Wed, 15 Jul 2026 00:00:00 GMT https://sparkfile.co/build-log/kokua-is-in-the-app-store https://sparkfile.co/build-log/kokua-is-in-the-app-store Wed, 15 Jul 2026 00:00:00 GMT Seventh build log. Two days after I wrote about submitting Kōkua and not knowing if it'd get approved, Shopify approved it. It's live on the App Store. https://sparkfile.co/build-log/the-one-the-filter-kept https://sparkfile.co/build-log/the-one-the-filter-kept Mon, 13 Jul 2026 00:00:00 GMT Sixth build log. I ran a batch of ideas through my own filter. It benched the three I was excited about and kept an accessibility scanner I didn't want to build. Three days later it's a submitted Shopify app and a real company, and I still don't know if it'll get approved. https://sparkfile.co/library/validate-demand-before-you-build https://sparkfile.co/library/validate-demand-before-you-build Fri, 10 Jul 2026 00:00:00 GMT Pull real search-demand signal for your idea, its category, and a competitor — programmatically, no screenshots — and get a plain read on whether interest is growing or dying before you commit a week to building. https://sparkfile.co/build-log/sonic-bloom-two-attempts-different-fear https://sparkfile.co/build-log/sonic-bloom-two-attempts-different-fear Mon, 06 Jul 2026 00:00:00 GMT Fifth build log. Ten months, two attempts, three rebuilds, and a quiet quit in between, including the part I almost left out: neither time did I ask anyone in person. I posted instead, both times, and I'm still not sure if that's a distribution problem or something I'm avoiding. https://sparkfile.co/build-log/an-app-in-a-day-then-a-two-week-wait https://sparkfile.co/build-log/an-app-in-a-day-then-a-two-week-wait Sun, 05 Jul 2026 00:00:00 GMT Fourth build log. I checked my own commit history and found the real number: about 13 hours of work, under 24 hours start to finish. Then Apple's approval queue took over, and two and a half weeks later I'm still waiting. https://sparkfile.co/library/idea-filter-before-you-hire-the-team https://sparkfile.co/library/idea-filter-before-you-hire-the-team Sat, 04 Jul 2026 00:00:00 GMT Four gates and two human checks that turn 'should I build this' into a verdict (Keep, Bench, or Scrap) before you write a single role file. https://sparkfile.co/build-log/notifications-to-dispatch https://sparkfile.co/build-log/notifications-to-dispatch Sat, 04 Jul 2026 00:00:00 GMT Third build log. I wired my AI team to text me for approvals, then nearly built a whole service to reply from my phone, before I caught that I was reinventing something Claude already ships. The catch is the point. https://sparkfile.co/build-log/founding-four-first-live-run https://sparkfile.co/build-log/founding-four-first-live-run Fri, 03 Jul 2026 00:00:00 GMT Second build log. I stood up the whole Founding Four on a real business: three AI cofounders, a chief of staff, an approval gate, all from the guide's templates. Then I turned it loose on a first batch. Here's what the process actually revealed, including the moment a cofounder refused to make something up. https://sparkfile.co/library/claude-code-vs-cursor https://sparkfile.co/library/claude-code-vs-cursor Wed, 01 Jul 2026 00:00:00 GMT Cursor is a full code editor with AI built in; Claude Code is conversation-and-diff-first with no editor to learn. The right pick depends on whether you want to live in an IDE or not. https://sparkfile.co/library/claude-vs-chatgpt-one-question https://sparkfile.co/library/claude-vs-chatgpt-one-question Wed, 01 Jul 2026 00:00:00 GMT Skip the benchmark comparisons — the useful test is running your own actual, recurring task on both and judging the output against what you know to be true. https://sparkfile.co/library/cowork-vs-no-code-builders https://sparkfile.co/library/cowork-vs-no-code-builders Wed, 01 Jul 2026 00:00:00 GMT No-code builders are for structured, persistent apps with a defined data model. Cowork is for conversational, judgment-heavy workflows. Most founders need both, for different jobs. https://sparkfile.co/library/free-vs-paid-claude https://sparkfile.co/library/free-vs-paid-claude Wed, 01 Jul 2026 00:00:00 GMT A framework for deciding whether to pay, since exact plans and prices change: usage volume, whether you need Cowork or Claude Code, and how much context you regularly need in one conversation. https://sparkfile.co/build-log/running-the-roadmap-on-my-own-agency https://sparkfile.co/build-log/running-the-roadmap-on-my-own-agency Wed, 01 Jul 2026 00:00:00 GMT First build log. I ran Sparkfile's own 90-day roadmap on my own agency and it broke in a useful way: it assumed I was a product startup. Here's what the setup actually looked like, the pricing shift it forced, the two workflows that came out of it, and how it changed the roadmap. https://sparkfile.co/library/case-study-from-customer-call https://sparkfile.co/library/case-study-from-customer-call Tue, 30 Jun 2026 00:00:00 GMT Turns one good customer call into a real case-study draft — built from what they actually said, not invented quotes. https://sparkfile.co/library/chat-vs-cowork-vs-code https://sparkfile.co/library/chat-vs-cowork-vs-code Tue, 30 Jun 2026 00:00:00 GMT Three surfaces, one underlying model — the choice is about how much you want to review each step, not which one is smarter. https://sparkfile.co/library/could-claude-cover-this-role https://sparkfile.co/library/could-claude-cover-this-role Tue, 30 Jun 2026 00:00:00 GMT Before writing a JD, a plain framework for whether the role is actually a hiring problem or a workflow you haven't built yet. https://sparkfile.co/library/first-three-hires-ai-native-founders-delay https://sparkfile.co/library/first-three-hires-ai-native-founders-delay Tue, 30 Jun 2026 00:00:00 GMT Three roles that traditionally get hired early but that a founder running real workflows on Claude can often cover solo for longer than expected. https://sparkfile.co/library/fundraising-faq-before-investors-ask https://sparkfile.co/library/fundraising-faq-before-investors-ask Tue, 30 Jun 2026 00:00:00 GMT Drafts honest answers to the hard questions before you're put on the spot in a room, using your real numbers and your real weak spots. https://sparkfile.co/library/lightweight-crm-from-spreadsheet https://sparkfile.co/library/lightweight-crm-from-spreadsheet Tue, 30 Jun 2026 00:00:00 GMT Turns a plain spreadsheet of prospects into something that behaves like a CRM — stage tracking, follow-up flags, and a weekly summary — with no new tool to buy. https://sparkfile.co/library/rank-user-interviews https://sparkfile.co/library/rank-user-interviews Tue, 30 Jun 2026 00:00:00 GMT Hand Claude all your interview transcripts at once and make it count and rank requests — with the quotes cited so you can trust it. https://sparkfile.co/library/seed-deck-narrative https://sparkfile.co/library/seed-deck-narrative Tue, 30 Jun 2026 00:00:00 GMT Drafts the actual narrative arc of a seed deck from your real story — not slide-by-slide copy, the through-line that makes the slides make sense. https://sparkfile.co/library/signal-its-time-to-hire https://sparkfile.co/library/signal-its-time-to-hire Tue, 30 Jun 2026 00:00:00 GMT Not 'I'm busy' — the actual signal is a specific, recurring, judgment-heavy task that a workflow genuinely can't cover, showing up consistently for weeks. https://sparkfile.co/library/30-60-90-plan-for-new-hire https://sparkfile.co/library/30-60-90-plan-for-new-hire Mon, 29 Jun 2026 00:00:00 GMT Drafts a specific, honest first-90-days plan for a new hire, instead of a generic template that doesn't reflect what your company actually needs from them. https://sparkfile.co/library/changelog-from-git-history https://sparkfile.co/library/changelog-from-git-history Mon, 29 Jun 2026 00:00:00 GMT Turns a week of commit history into a real, user-readable changelog entry — without you writing it from memory after the fact. https://sparkfile.co/library/founder-does-sales-playbook https://sparkfile.co/library/founder-does-sales-playbook Mon, 29 Jun 2026 00:00:00 GMT A repeatable weekly rhythm for doing your own sales — research, outreach, and follow-up — without a sales background or a sales team. https://sparkfile.co/library/term-sheet-in-plain-english https://sparkfile.co/library/term-sheet-in-plain-english Mon, 29 Jun 2026 00:00:00 GMT A term sheet is a non-binding summary of a deal's key terms — the fastest way to understand one is to have Claude translate the actual document into plain language, clause by clause. https://sparkfile.co/library/what-is-a-context-window https://sparkfile.co/library/what-is-a-context-window Mon, 29 Jun 2026 00:00:00 GMT The context window is everything Claude can see at once for a given response — your prompt, your files, the conversation so far. Nothing outside it exists to the model. https://sparkfile.co/library/what-is-an-llm https://sparkfile.co/library/what-is-an-llm Mon, 29 Jun 2026 00:00:00 GMT An LLM predicts likely next words from patterns in its training — which explains both why it's useful and exactly where it'll quietly go wrong. https://sparkfile.co/library/what-is-inference https://sparkfile.co/library/what-is-inference Mon, 29 Jun 2026 00:00:00 GMT Training happens once, ahead of time, and you don't touch it. Inference is every single response Claude gives you — the part you actually interact with. https://sparkfile.co/library/what-is-rag https://sparkfile.co/library/what-is-rag Mon, 29 Jun 2026 00:00:00 GMT RAG means fetching the relevant piece of a large pile of documents before answering, instead of stuffing everything into context at once. https://sparkfile.co/library/what-is-synthesis https://sparkfile.co/library/what-is-synthesis Mon, 29 Jun 2026 00:00:00 GMT Synthesis is turning a pile of scattered user feedback into a ranked, countable signal — the step founders skip because it's tedious, not because it's hard. https://sparkfile.co/library/find-the-ignored-feature-request https://sparkfile.co/library/find-the-ignored-feature-request Sun, 28 Jun 2026 00:00:00 GMT Surfaces the request that keeps quietly recurring across support tickets, calls, and interviews — the one that's easy to dismiss individually but adds up. https://sparkfile.co/library/how-to-write-a-prompt-that-works https://sparkfile.co/library/how-to-write-a-prompt-that-works Sun, 28 Jun 2026 00:00:00 GMT The gap between a bad prompt and a good one is almost never cleverness — it's context, specificity, and telling Claude what you actually want back. https://sparkfile.co/library/metrics-dashboard-with-no-analyst https://sparkfile.co/library/metrics-dashboard-with-no-analyst Sun, 28 Jun 2026 00:00:00 GMT Turns raw exports from wherever your data actually lives into a real, readable metrics view — no analyst, no BI tool license required. https://sparkfile.co/library/screen-resumes-without-reading-all https://sparkfile.co/library/screen-resumes-without-reading-all Sun, 28 Jun 2026 00:00:00 GMT Scores a pile of résumés against a rubric you wrote once, so you spend your limited hiring time on the shortlist instead of the whole stack. https://sparkfile.co/library/what-is-a-data-room https://sparkfile.co/library/what-is-a-data-room Sun, 28 Jun 2026 00:00:00 GMT A data room is the folder of documents serious investors expect before they'll move — assembling it before it's asked for saves the exact week you don't have during a raise. https://sparkfile.co/library/claude-code-permission-modes https://sparkfile.co/library/claude-code-permission-modes Sat, 27 Jun 2026 00:00:00 GMT Claude Code has explicit permission modes, from asking before every edit to acting more autonomously — the right setting depends on what it's touching, not on how much you trust it in general. https://sparkfile.co/library/fix-the-bug-you-cant-find https://sparkfile.co/library/fix-the-bug-you-cant-find Sat, 27 Jun 2026 00:00:00 GMT Turns a vague, hard-to-reproduce bug into a real fix by having Claude Code investigate the actual codebase instead of guessing from a description. https://sparkfile.co/library/hand-claude-the-spreadsheet https://sparkfile.co/library/hand-claude-the-spreadsheet Sat, 27 Jun 2026 00:00:00 GMT The single most common way founders get a vague investor update: they describe their metrics in a sentence instead of pasting the real numbers in. https://sparkfile.co/library/onboarding-emails-as-a-sequence https://sparkfile.co/library/onboarding-emails-as-a-sequence Sat, 27 Jun 2026 00:00:00 GMT Drafts a full onboarding email sequence in your own voice, grounded in what new users actually need to succeed with your product. https://sparkfile.co/library/what-a-skill-is https://sparkfile.co/library/what-a-skill-is Sat, 27 Jun 2026 00:00:00 GMT A skill is a reusable instruction set you write once instead of re-explaining every time — the difference between a one-off prompt and a real tool. https://sparkfile.co/library/ship-landing-page-with-claude-code https://sparkfile.co/library/ship-landing-page-with-claude-code Fri, 26 Jun 2026 00:00:00 GMT Ships a real, working landing page by describing what you want and reviewing Claude Code's actual changes — no prior coding experience required. https://sparkfile.co/library/what-are-hooks https://sparkfile.co/library/what-are-hooks Fri, 26 Jun 2026 00:00:00 GMT A hook triggers an automatic action around something Claude Code does — mostly an engineering tool, worth knowing about even if you rarely reach for it directly. https://sparkfile.co/library/what-are-subagents https://sparkfile.co/library/what-are-subagents Fri, 26 Jun 2026 00:00:00 GMT A subagent is a specialist Claude Code can delegate a piece of work to — useful for heavier research or multi-part tasks, rarely needed for a founder's everyday work. https://sparkfile.co/library/what-is-a-connector-mcp https://sparkfile.co/library/what-is-a-connector-mcp Fri, 26 Jun 2026 00:00:00 GMT A connector lets Claude read and act on a real tool you already use — Gmail, your calendar, a CRM — instead of you copy-pasting between tabs. https://sparkfile.co/library/what-is-icp https://sparkfile.co/library/what-is-icp Fri, 26 Jun 2026 00:00:00 GMT ICP means the specific person who buys fast and stays — writing yours down is what makes every other outreach workflow actually work. https://sparkfile.co/library/wire-up-stripe-with-claude-code https://sparkfile.co/library/wire-up-stripe-with-claude-code Fri, 26 Jun 2026 00:00:00 GMT Adds real payment collection to your product with Claude Code — with the review discipline real money handling actually deserves. https://sparkfile.co/library/product-roadmap-from-notion-notes https://sparkfile.co/library/product-roadmap-from-notion-notes Thu, 25 Jun 2026 00:00:00 GMT Turns scattered planning docs and half-finished notes into a real, prioritized roadmap you can actually show someone. https://sparkfile.co/library/reading-your-first-claude-code-diff https://sparkfile.co/library/reading-your-first-claude-code-diff Thu, 25 Jun 2026 00:00:00 GMT A diff shows exactly what changed, line by line — red for removed, green for added. Learning to read one is the actual skill that makes Claude Code worth using over chat. https://sparkfile.co/library/ship-a-waitlist-in-an-afternoon https://sparkfile.co/library/ship-a-waitlist-in-an-afternoon Thu, 25 Jun 2026 00:00:00 GMT Ships a real, working waitlist page with email capture in one sitting — no page builder, no template fighting. https://sparkfile.co/library/what-is-cowork https://sparkfile.co/library/what-is-cowork Thu, 25 Jun 2026 00:00:00 GMT Cowork is for anything that needs to run more than once, or take several steps on its own — the middle ground between chat and Claude Code. https://sparkfile.co/library/spec-first-building https://sparkfile.co/library/spec-first-building Wed, 24 Jun 2026 00:00:00 GMT A short spec written before you build catches the vague parts of an idea while they're still cheap to fix — before you or Claude have written a line of code. https://sparkfile.co/library/terminal-commands-a-founder-needs https://sparkfile.co/library/terminal-commands-a-founder-needs Wed, 24 Jun 2026 00:00:00 GMT Six commands cover almost everything a founder needs to navigate a terminal well enough to use Claude Code's CLI — the rest you can skip. https://sparkfile.co/library/what-is-claude-code https://sparkfile.co/library/what-is-claude-code Wed, 24 Jun 2026 00:00:00 GMT Claude Code reads a folder on your machine and remembers it — the difference between a chat tab and something that actually edits your files. https://sparkfile.co/library/your-first-30-minutes-with-claude-code https://sparkfile.co/library/your-first-30-minutes-with-claude-code Wed, 24 Jun 2026 00:00:00 GMT A literal, minute-by-minute walkthrough of opening Claude Code for the first time and getting it to do something real. https://sparkfile.co/library/what-is-a-memory-file https://sparkfile.co/library/what-is-a-memory-file Tue, 23 Jun 2026 00:00:00 GMT A memory file tells Claude the things it would otherwise ask you every time — what you're building, who your users are, how you write.