PerUnit VS StackSpend.app

PerUnit's answer

PerUnit is built for AI unit economics, not just cost tracking. We break down AI spend by:

Customer — see which accounts drive costs Feature — see which AI features burn through tokens Pricing tier — free vs paid user breakdown We connect AI costs to revenue via Stripe. Provider dashboards show totals; observability tools show tokens. PerUnit shows who's driving costs and whether they're profitable. No data warehouse or pipelines — direct API sync to OpenAI, Anthropic, and Google.

StackSpend.app's answer:

StackSpend traces every dollar of cloud and AI spend back to the code, team, and pull request that caused it. Where traditional cost tools show you that spend moved, StackSpend's cost-to-code correlation shows you why — automatically tying each anomaly to the deploy, config change, or PR behind it. It unifies traditional cloud (AWS, Azure, GCP, Snowflake) and modern AI spend (OpenAI, Anthropic, Cursor) in one view, detects anomalies daily instead of at month-end, and works from day one without a data team building dashboards.

PerUnit's answer

PerUnit is built for product and pricing decisions, not observability. Competitors focus on tokens, latency, and traces. We focus on:

Cost per customer Cost per feature Cost per tier — connected to revenue If you need to know who to charge more, what to gate, or where to cut, PerUnit gives you that. No pipelines, no data engineering, no data warehouse.

StackSpend.app's answer:

Legacy FinOps tools were built for the AWS-only era: they stop at a chart, bill you a percentage of your cloud spend, and can't explain what changed. StackSpend is different on three fronts — it explains the cause of every spike (cost-to-code correlation), it covers AI/LLM spend as a first-class citizen alongside cloud, and it uses flat, predictable per-tier pricing so your cost-management bill never grows just because your cloud bill did. Setup takes minutes, and a 14-day free trial doubles as a free cost-health audit.

PerUnit's answer

Founders, product managers, and CFOs at companies building AI-powered products. Anyone who needs to answer:

Which customers cost the most? Are free users profitable? Should we gate AI behind paid plans? Teams that care about unit economics and margins, not just total spend.

StackSpend.app's answer:

Engineering and finance teams who share responsibility for cloud and AI spend — platform/DevOps engineers, engineering leaders, and FinOps or finance practitioners. It's built for teams running a mix of cloud infrastructure and AI/LLM services who need daily visibility and a shared source of truth, from fast-moving startups through mid-market and enterprise organizations.

PerUnit's answer

We've shipped products with AI and watched margins disappear without knowing why. The AI bill was one number — we couldn't see which customers or features were driving it. Every product and pricing decision was a guess.

We built PerUnit so product teams can have the same clarity on AI costs that they have on revenue and headcount.

StackSpend.app's answer:

StackSpend was built by engineers who spent years watching cloud bills climb — and then watching AI make them climb faster. Founder Andrew Day spent a decade building large-scale systems in regulated banking, where every dollar of infrastructure was accounted for, then eight years in AI startups where teams spent across OpenAI, Anthropic, Cursor, and a dozen cloud services with no way to say why the bill jumped. The cause was almost always a code change — a PR that flipped a model or widened a query — but finance dashboards never connected spend to the code behind it. So StackSpend was built to close that gap and turn a monthly surprise into a daily signal.

PerUnit's answer

Frontend: Next.js, React, TypeScript, Tailwind CSS Integrations: OpenAI, Anthropic, Google APIs, Stripe Deployment: Vercel

StackSpend.app's answer:

StackSpend is a TypeScript monorepo (Turborepo). The web app is built with Next.js 15, React 19, and Tailwind CSS, deployed on Vercel. The backend API is a Node.js/Express service on Railway, with Supabase (PostgreSQL) for data and auth. Cost forecasting is powered by a Python FastAPI service using Prophet, pandas, and NumPy. AI/LLM features run through a dedicated agents service (Anthropic Claude), and the platform ingests cost data via native provider APIs and the open FOCUS standard.

PerUnit's answer

PerUnit is in early access. We're onboarding a small group of teams who need clarity on their AI unit economics. Our early users are founders and PMs at companies building AI features — from early-stage to growth — who want cost attribution before scaling further.