Fixed-Bid Software Delivery
The unknown in your quote isn't the weather. It's the scope.
A construction estimator prices against a known trade and a known site. You're pricing against a spec that will change, a legacy codebase you haven't opened yet, and a third-party API whose docs are wrong. back-napkin turns those unknowns into a risk-adjusted range you can actually stand behind in a fixed-bid quote.
Fixed-bid software estimates fail for specific, recurring reasons
Not bad luck — the same handful of risk factors, project after project. back-napkin's Software pack models them directly instead of leaving them as gut feel.
Scope creep from unclear requirements
The most common overrun on a fixed-bid build: the brief was never fully nailed down, and every clarification becomes a change. back-napkin's Fixed-bid web app Starter flags this as a Likely risk before you've written a line of code.
Platform and codebase change the risk profile
Web, mobile, and API-only work carry different failure modes, and a greenfield build is a different bet than inheriting someone else's codebase. back-napkin's Platform and Codebase attribute axes push your estimate up or down accordingly, instead of using one baseline for every job.
Third-party integrations are where estimates die
Docs that lie, rate limits you didn't know about, sandboxes that behave nothing like production. back-napkin tracks integration count as its own attribute axis — 0, 1-2, 3-5, or 6+ — because five integrations isn't "some more work," it's a different project.
Brownfield unknowns you can't see until you're inside the code
A legacy codebase hides its own scope. back-napkin's Codebase axis separates greenfield from brownfield work up front, so the estimate accounts for unfamiliar territory before it becomes a surprise change order.
Start from the work you actually ship
Three Project Starters, each with a real work-item tree — not a blank page.
Fixed-bid web app
Discovery and planning through frontend, backend, third-party integrations, testing, and client handover — the full build, broken into the phases a fixed-bid quote actually has to price.
API integration
Spec review and data mapping, authentication and connection handling, error handling and retry logic, then testing against sandbox and live data before handover — scoped for integration work specifically, not treated as a mini web app.
Website build
Sitemap and content planning through CMS setup, page templates, forms, and DNS cutover — for the content-driven builds that live alongside your application work.
Built from real risk checklists, not generic advice
A sample of the risk items back-napkin checks against your estimate before you send the quote.
Scope creep from unclear requirements
Likely — effort +15-30% without change control.
Third-party API documentation inaccurate or incomplete
Likely — effort +20-40% on discovery/build.
Client content delivery delays
Likely — schedule slip, the largest single delay source on this Starter.
Quote fixed-bid work with the scope risk priced in
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