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Product Engineering

Production-Ready Web Products, End to End

We design, build, and ship full-stack applications with modern AI, authentication, billing, and data infrastructure. Engagements focus on clean architecture, fast delivery, and maintainable systems teams can extend.

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Yuji Tabata
Genuine Engineering

Battle-Tested Instincts

AfterAI is led by a career software engineer — not a prompt wrapper. From Tesla's navigation stack to production web apps, every architecture decision comes from years of shipping real systems.

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What We Build

Full-stack product engineering across UX, backend systems, and operations

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Full-Stack Web Apps

Type-safe React frontends and resilient backend services with SSR/SPA architecture, clear domain boundaries, and performance budgets.

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AI-Powered Features

LLM features with structured outputs, streaming, tool orchestration, guardrails, and observability to keep AI behavior stable in production.

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Auth & Payments

Secure authentication flows, role-based access control, subscription billing, and usage metering for SaaS-style products.

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Database & Infrastructure

PostgreSQL data modeling, migration strategy, CI/CD, release automation, and production telemetry across logs, metrics, and alerts.

Featured Build

babysteps

A production learning platform with AI lesson generation, interactive assessment, and adaptive UX. The system personalizes content by time context while keeping latency and lesson quality consistent across sessions.

Try babysteps →
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Case Study: babysteps

Designed, built, and launched in one month with a full production stack

babysteps delivers AI-generated micro-lessons, interactive quizzes, and revision workflows on a modern full-stack architecture. The platform combines prompt orchestration, structured persistence, and adaptive scheduling to support repeatable learning outcomes.

Tech Stack

Frontend
TanStack Start (React 19)
Database
PostgreSQL + Drizzle ORM
AI
Google Gemini
Auth
Better Auth + Google OAuth
Payments
Polar Subscriptions
Notifications
Web Push (VAPID)

Key Features Delivered

  • AI-generated lessons with math & diagrams
  • Interactive quizzes with instant feedback
  • AI tutor chat for follow-up questions
  • Spaced repetition review system
  • Progress analytics dashboard
  • Time-of-day adaptive themes
  • Free & Pro tier with credit metering
  • Hierarchical subject organization

Need a team that can ship?

Share your scope and constraints. We can map the architecture, prioritize milestones, and start building.

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