# finops-architect-toolkit FinOps calculators for AWS architects: RI, S3, Lambda, and tagging strategy. - URL: https://fernando.moretes.com/open-source/finops-architect-toolkit - Markdown: https://fernando.moretes.com/open-source/finops-architect-toolkit/guide.md?lang=en - GitHub: https://github.com/fernandofatech/finops-architect-toolkit - Language: TypeScript - Topics: - Stars: 0 - Forks: 0 - Updated: 2026-05-16T02:18:59Z --- finops-architect-toolkit is a Next.js 16 + TypeScript web application that gives solution architects a set of focused cost calculators — EC2 Reserved Instance break-even, S3 storage-class optimizer, Lambda cost estimator, and a tagging strategy generator — designed to support real procurement and engineering conversations about AWS spend. ## Why I built this Architecture decisions drive the majority of a cloud bill. When I sit in a room with procurement, engineering, and finance, the conversation stalls because each group is working from different spreadsheets with different assumptions. I built this toolkit to close that gap with a single, shareable URL. Each calculator is self-contained and opinionated: it asks only the inputs that actually move the needle and surfaces the number that matters — break-even months for RIs, effective cost per GB-month across S3 storage tiers, total monthly spend for a Lambda workload given invocation rate, average duration, and memory. The tagging generator produces a structured allocation taxonomy aligned to FinOps Foundation recommendations, which I use as a starting point when defining cost allocation policies for clients. This is not a replacement for AWS Cost Explorer or Compute Optimizer. It is a conversation tool — fast, transparent, and reproducible. The formulas are visible in the source, so any engineer can audit them, challenge the assumptions, and adapt them to their own pricing agreements. ## What the toolkit includes - **EC2 RI vs On-Demand calculator** — computes break-even month and total savings over 1- or 3-year terms for Standard and Convertible RIs. - **S3 storage-class optimizer** — compares effective cost per GB-month across Standard, Standard-IA, Glacier Instant Retrieval, and Deep Archive, factoring in retrieval frequency. - **Lambda cost estimator** — calculates monthly compute cost from invocation count, average duration (ms), and allocated memory (MB), aligned to current AWS pricing. - **Tagging strategy generator** — produces a structured tag taxonomy (environment, cost-center, team, workload, data-classification) ready to paste into an AWS Organizations tag policy. - **Cost allocation report templates and showback/chargeback patterns** — reusable starting points for internal billing models. - **CI/CD with GitHub Actions** — three pipelines (CI, Frontend/Vercel deploy, Security scan) keep the live site at finops.moretes.com always current. ## How the application is structured The toolkit is a purely client-side Next.js app — all calculations run in the browser. There is no backend API. Deployment is automated via GitHub Actions to Vercel, with DNS managed through Cloudflare. ### 👤 User - Architect browser (user) ### 🌐 Edge / CDN - Cloudflare DNS + proxy (edge) ### ☁️ Hosting - Vercel Next.js 16 SSG (frontend) ### 💻 Frontend Modules - RI vs On-Demand calculator (compute) - S3 storage-class optimizer (compute) - Lambda cost estimator (compute) - Tagging strategy generator (compute) ### 🔁 CI/CD - GHA: CI lint + type-check (ci) - GHA: Frontend Vercel deploy (ci) - GHA: Security scan (security) ### Flows - user -> cloudflare: HTTPS request - cloudflare -> vercel: proxy - vercel -> ri_calc: route /ri - vercel -> s3_opt: route /s3 - vercel -> lambda_est: route /lambda - vercel -> tag_gen: route /tagging - gha_ci -> vercel: on push - gha_fe -> vercel: deploy - gha_sec -> gha_ci: parallel scan ## Tech stack and design decisions The frontend is built with **Next.js 16** and **React 19**, styled with **Tailwind CSS 4**, and written entirely in **TypeScript 5**. I chose Next.js because static generation gives me zero-latency page loads and trivial Vercel deployment — there is no server to manage, no database to provision, and no API to secure. All calculation logic lives in pure TypeScript functions that are easy to unit-test and audit. Three GitHub Actions workflows run on every push: a **CI pipeline** that runs lint and type-checking, a **Frontend pipeline** that builds and deploys to Vercel, and a **Security pipeline** that scans dependencies and static code. The security workflow is not cosmetic — I treat a public portfolio repo the same way I treat a production service: supply-chain hygiene matters. Tailwind CSS 4 keeps the styling co-located with components and eliminates the need for a separate design-system package at this scale. The result is a codebase that any TypeScript engineer can clone, read, and extend in under an hour. The live site is served from **finops.moretes.com**, deployed on Vercel with DNS proxied through Cloudflare for DDoS protection and caching at the edge. ## Running locally 1. **Clone the repository** — Run `git clone https://github.com/fernandofatech/finops-architect-toolkit.git` and enter the project directory. 2. **Install dependencies** — Navigate to the `frontend` directory and run `npm install`. Node 18+ is recommended to match the Vercel runtime. 3. **Start the development server** — Run `npm run dev`. The app will be available at `http://localhost:3000`. Hot reload is enabled — changes to calculator logic or styles are reflected immediately. 4. **Build for production** — Run `npm run build` followed by `npm start` to verify the static output locally before pushing. Review `SETUP.md` and `OPERATIONS.md` for deployment-specific configuration. 5. **Review architecture documentation** — Read `docs/architecture.md` for a deeper explanation of each calculator's formula assumptions and the tagging taxonomy rationale. _Quick start — clone, install, and run in three commands_ ```bash git clone https://github.com/fernandofatech/finops-architect-toolkit.git cd finops-architect-toolkit/frontend npm install && npm run dev # App available at http://localhost:3000 ``` > **All calculations are client-side and auditable:** There is no backend, no API call, and no telemetry. Every formula runs in the browser and is readable in the TypeScript source. If your organization has negotiated custom pricing or EDP discounts, you can fork the repo and adjust the rate constants directly — the code is intentionally straightforward. ## Common questions ### Are the AWS prices in the calculators kept up to date? The rate constants in the source reflect AWS public pricing at the time of each commit. AWS changes prices infrequently for compute and storage, but you should verify against the official AWS Pricing pages before using outputs in a formal business case. The formulas are transparent enough that updating a rate is a one-line change. ### Can I use this toolkit with Savings Plans instead of Reserved Instances? The current RI calculator models Standard and Convertible RIs. Savings Plans have a different commitment structure ($/hour rather than per-instance). The calculator does not currently model Savings Plans — that is a known gap and a reasonable contribution if you want to extend the project. ### Is this suitable for multi-account AWS Organizations environments? The tagging strategy generator is explicitly designed with multi-account allocation in mind — the taxonomy it produces maps to AWS Organizations tag policies and Cost Categories. The calculators themselves are workload-scoped, not account-scoped, so you would run them per workload and aggregate manually. ### Why Next.js for a toolkit that has no server-side logic? Static generation, file-based routing, and zero-config Vercel deployment make Next.js a pragmatic choice even for fully static sites. The alternative — a plain Vite SPA — would have been equally valid. I chose Next.js because it aligns with how I build production frontends and keeps the door open for adding server components or API routes later without a rewrite. ## Who this is for This toolkit is for solution architects and cloud engineers who need to make cost trade-offs legible to non-technical stakeholders — quickly, without building a custom spreadsheet for every engagement. If you are running a FinOps practice, preparing a migration business case, or defining a tagging governance model for a new AWS environment, the calculators give you a reproducible starting point that you can share as a URL or fork and adapt. It is not a monitoring tool, not a cost anomaly detector, and not a replacement for AWS Cost Explorer. It is a planning and communication aid. The source is MIT-licensed, the formulas are auditable, and the architecture is simple enough that adapting it to your organization's specific pricing or taxonomy takes hours, not days. The live version is at [finops.moretes.com](https://finops.moretes.com) if you want to try it before cloning. ## References and links - [GitHub — fernandofatech/finops-architect-toolkit](https://github.com/fernandofatech/finops-architect-toolkit) - [Live site — finops.moretes.com](https://finops.moretes.com) - [AWS EC2 Reserved Instances pricing](https://aws.amazon.com/ec2/pricing/reserved-instances/) - [AWS S3 storage classes pricing](https://aws.amazon.com/s3/pricing/) - [AWS Lambda pricing](https://aws.amazon.com/lambda/pricing/) - [FinOps Foundation — Tagging and allocation](https://www.finops.org/framework/capabilities/cost-allocation/) - [Next.js 16 documentation](https://nextjs.org/docs) ## Links - [GitHub repository](https://github.com/fernandofatech/finops-architect-toolkit)