Los Angeles, CA

You've been lookingfor someone who takesan idea all the wayto production.

You've been lookingfor someone whotakes an ideaall the wayto production.

I'm Aga.
Full-stackNext.jsAI integrationsArchitecture
Selected work

What I've Built

01
Featured

E-Commerce Platform

Revenue-critical checkout system for one of Europe’s largest e-commerce platforms — handling thousands of daily transactions.

1.5 years in a Scrum team where every change touched real money. Learned how milliseconds and microcopy directly move conversion rates.

ReactReduxStripeREST APIsTypeScript
02
In Progress

Claro

Multi-tenant marketplace where every vendor gets their own subdomain, isolated data layer, and Stripe Connect payouts.

Next.js 15 + Payload CMS 3 + tRPC v11. AI description generator streams product copy directly into the Payload admin UI.

Next.js 15Payload CMS 3tRPC v11Stripe ConnectClaude API
View code →
03
Coming Soon

AI Video Calls Platform

Next project. Details coming soon.

Next.jsAIReal-time
About

The most expensive mistakes don't throw errors. They accumulate quietly until someone notices the revenue is wrong.

I learned that building checkout systems for over a million users. 1.5 years in production where downtime wasn't an option. You develop a certain instinct — for what looks fine but isn't, for the decision that feels small now and costs real money in three months.

I bring that instinct to everything I build. Not just the feature in front of me — but what it touches, what it assumes, what happens when it meets real users doing unexpected things.

I'm in Los Angeles, building my own products and taking on a project or two a year — for people who want the thinking done, not just the code written.

Aga Kadela
Process

How I Work

Production Pattern

Idempotency via Unique Index

Stripe can deliver the same webhook twice. Without protection, one payment creates two orders. The fix uses infrastructure already there.

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Production Pattern

Vendor Isolation — Information Hiding

When a buyer requests a product from a different vendor, confirming it exists leaks information. Isolation is every layer making the same assumption.

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AI Workflow

Code Review Prompt

Solo developers don’t get code reviewed. This prompt fills that gap before every merge — tracing user flows, stale state, real security gaps.

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AI Workflow

Project Rules Before I Write a Line

Before I start any project I write rules that make AI build in my conventions — not around them. Every token, animation, and pattern defined upfront.

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Contact

Get in touch

The right project shows up maybe twice a year. It's usually someone who has a real problem, knows what they want to build, and needs someone to own the technical side — not manage it.

If that's you — tell me what you're building.