# TestaAí

> Zero's technical portfolio: full-stack systems, SaaS products, applied AI, fintech and games built from scratch.

Technical portfolio in English, built by Zero. Cases record hypotheses, architecture, trade-offs, possible failures, candidate signals, and next steps. Editorial metrics and hypothetical stages are marked provisional and must not be cited as measured results.

## Start here

- [Manifesto](https://www.testaai.dev.br/en): Brand principles and product-lab vision
- [Recruiter briefing](https://www.testaai.dev.br/en/briefing): Printable summary of capabilities, evidence, and interview routes
- [Portfolio engineering](https://www.testaai.dev.br/en/engineering): Budgets, architecture, accessibility, security, and delivery gates
- [Zero profile](https://www.testaai.dev.br/en/zero): Scope, principles, operating rhythm, and evaluation criteria

## Projects

- [Project Renaissance](https://www.testaai.dev.br/en/experiments/renaissance): QUANT / FINTECH; A quantitative system built with .NET 10, ProfitDLL, ticks, backtests, strategies, and OMS/Risk. It runs in shadow mode; live execution requires explicit enablement.
- [ERP](https://www.testaai.dev.br/en/experiments/erp): OPERATIONS / SAAS; Management for schools, fitness studios, and sports operations: students, enrollments, contracts, and billing. It connects signatures, payments, and WhatsApp in one flow.
- [Castle Wars](https://www.testaai.dev.br/en/experiments/castle-wars): STRATEGY / GAME; A multiplayer strategy game inspired by Tribal Wars 2. The prototype covers authentication, lobby, worlds, realtime, and the first resource-and-construction loop.
- [Auto Whats](https://www.testaai.dev.br/en/experiments/auto-whats): AUTOMATION / AI; Connects WhatsApp by QR code, organizes the CRM, and uses business-aware AI to respond, qualify leads, schedule, follow up, and hand conversations to people.
- [AI_VTT](https://www.testaai.dev.br/en/experiments/ai-vtt): RPG / GENERATIVE GAME; A solo or two-player virtual tabletop with a persistent lobby, exploration, and combat. The AI game master works through text or voice without controlling the rules.
- [Desafio Online](https://www.testaai.dev.br/en/experiments/desafio-online): PUZZLE / SOCIAL GAME; A platform for pairs and groups with teams, invitations, and persistent expeditions. The Impossible Map combines clues, timed hints, and shared progress.
- [Our Home](https://www.testaai.dev.br/en/experiments/our-home): MOBILE / HOUSEHOLD; An iPhone app where couples and families share shopping, recurring tasks, and responsibilities with real-time synchronization.

## Writing

- [How to create an impressive interface without shipping a full SPA](https://www.testaai.dev.br/en/blog/impressive-interface-without-a-full-spa): Frontend; A frontend architecture guide to combining visual presence, static rendering, interactive islands, adaptive accessibility, and real budgets.
- [Human handoff in AI automation: authority before the reply](https://www.testaai.dev.br/en/blog/human-handoff-in-ai-automations): Architecture; A practical architecture for preventing late replies, duplicated effects, and competition between AI agents and operators during human handoff.
- [AI with boundaries: why architecture comes before the prompt](https://www.testaai.dev.br/en/blog/ai-with-boundaries-architecture-before-the-prompt): Software engineering; An architecture guide for using AI models in products without handing rules, state, or critical decisions to probabilistic behavior.
- [How to validate a software idea before building everything](https://www.testaai.dev.br/en/blog/how-to-validate-a-software-idea): Product; A practical protocol for turning a software idea into a hypothesis, interviewing the right people, and testing value before expanding the product.
- [Building in public without turning the process into a spectacle](https://www.testaai.dev.br/en/blog/building-in-public-without-selling-certainty): Building in public; What is worth showing while building products in public, how to preserve privacy, and why transparency does not require selling certainty.

## Architecture decisions

- [ADR-001 — Static route, explicit islands](https://www.testaai.dev.br/en/engineering#adr-001): Pre-render content and metadata in Server Components; hydrate only nine modules with narrow responsibilities and named fallbacks.
- [ADR-002 — Motion constrained by the environment](https://www.testaai.dev.br/en/engineering#adr-002): Use a deterministic 2D canvas with capped density and DPR, visibility and intersection pauses, and reduced modes driven by preferences.
- [ADR-003 — Native primitives before custom controls](https://www.testaai.dev.br/en/engineering#adr-003): Prioritize links, anchors, tables, meter, details, and summary; add client behavior only when the primitive cannot solve the task.
- [ADR-004 — Public inspection without hidden observation](https://www.testaai.dev.br/en/engineering#adr-004): Publish portfolio.json, RSS, sitemap, and humans.txt with tested contracts; keep analytics, cookies, remote fonts, and pixels off the origin.

## Data and inspection

- [Portfolio contract](https://www.testaai.dev.br/en/portfolio.json): Complete deterministic catalog in JSON
- [Contract JSON Schema](https://www.testaai.dev.br/en/portfolio.schema.json): Executable Draft 2020-12 schema for validating the catalog
- [Lab RSS](https://www.testaai.dev.br/en/feed.xml): Feed of published writing
- [Human credits](https://www.testaai.dev.br/en/humans.txt): Team, technology, privacy, and interface shortcuts

## Optional

- [Visual catalog](https://www.testaai.dev.br/en/experiments): Comparative view of seven experiments and their engineering layers
- [Blog](https://www.testaai.dev.br/en/blog): Editorial index with five technical articles