allanhert.com · LinkedIn · X · Email · Hertwave
I build software end to end: the product decision, the architecture, the interface, the deploy and the fix two months later. Most days that means TypeScript and Next.js on the web, Python for automation and data, and LLM agents wired into real workflows with tests and human checkpoints.
I run Hertwave, a small studio in São Paulo that ships sites and software for real clients. I'm also finishing a law degree at Mackenzie, which shapes how I scope anything that touches personal data or a contract.
Most of my work lives in private repositories. Below are case studies that explain what each product does, how it is built and what I decided, plus the code I keep public.
A neutral public record of who backed whom in Brazil's 2026 presidential runoff, every endorsement linked to its source. Started on 2026-10-05, live the next day, frozen after the vote: 74,000 visits and about 518,000 views on X by 2026-10-25.
Focus: Zero to production in one day · AI triage with human review · Neutrality rules enforced in the data model
Stack: Next.js · TypeScript · Postgres (Neon) · Cloudflare R2 · Playwright · Claude
The platform behind a live real-estate agency: public site, admin, watermarked photos, XML feeds to Brazil's major listing portals and a CRM. Built multi-tenant from the schema up, with Postgres row-level security.
Focus: Full-stack platform · Portal integrations · Tenant isolation
Stack: Next.js · TypeScript · Supabase / Postgres · Cloudflare R2 · Vercel AI Gateway
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Jarvis Local-first voice assistant for Windows: Whisper wake word, local TTS, Claude Code acting on the PC through typed MCP tools that ask for confirmation. Python · Claude Code + MCP · faster-whisper · Tauri + React · Ollama · SQLite |
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Hertwave OS The studio's agent factory: Claude Code agents build client sites, a critic scores each render on a 9-part rubric and a fix is kept only if the score rises. Claude Code agents · Node.js · Playwright · Next.js · Tailwind v4 |
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Contratos Turns property records and ID scans into full real-estate contracts: 13 types, faithful to the agencies' own templates, with a human check on the deal sheet before the .docx. Python · Claude · JSON Schema · docxtpl |
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Quant research Systematic research for crypto and US equities: hypotheses registered before testing, a sealed holdout, a blind reviewer agent and paper trading with no orders. Python · Polars · statsmodels · pytest + Hypothesis · Claude Code agents |
| Site | What it shows |
|---|---|
| hertwave.com | Studio site: GLSL hero, 3D carousel in React Three Fiber, PT/EN. |
| nowimoveis.com | Video-first real estate: each YouTube tour becomes a property page in chapters, scroll drives the playhead. |
| nowmarketing.com.br | Agency site with a 3D opening scored to scroll. |
| oktal.com.br | Tech gadget store built as a studio portfolio piece. |
| jimmyk.com.br | One-page site for an old-school barbershop, built to drive WhatsApp bookings. |
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allanhert-portfolio My site and WebGL lab: GPU reaction-diffusion, SDF raymarching and ordered dithering, each one a hand-written shader. Next.js · Three.js · GLSL · Playwright |
Languages: TypeScript · JavaScript · Python · SQL · GLSL
Web: React · Next.js · Node.js · Tailwind · Three.js / React Three Fiber
Data and infra: Postgres · Neon · Supabase · Vercel · Linux VPS
AI: Claude Code agents · MCP servers · LLM extraction pipelines · local speech (Whisper, TTS)
Quality: Playwright · pytest · Vitest · axe-core
- Start from the real problem and the person using it, then pick the smallest thing that can go live.
- Write the decision down before the code: each project keeps its plan, phases and decision log in the repo.
- Agents do the heavy lifting, people approve anything irreversible: payments, messages, publishing.
- Test what can break, measure what ships, and keep secrets and personal data out of git.
Most client work is private. Case studies describe it without the source.