Currently shipping · 10 live products
Product Engineer

I architect, ship, and operate consumer + B2B products end‑to‑end.

From kernel driver to landing page. The app, the infrastructure, the release pipeline, and the story — one integrated system, owned end-to-end.

10 Live products
7 Production stacks
4 Platforms shipped
100% Solo built

Ten products. One operator.

Each one shipped, deployed, and operated as production software — not coursework or proofs of concept. Filter by surface to see how the stack changes with the problem.

All Products
03 LIVE

SimDex

Market Intelligence Tooling

Market tooling with faster information flow, stronger context, and real execution-adjacent depth. Board, wallet, Dex, room, company surfaces with quote preview, swap build, auth, bookmarks, and social tools.

Finance Real API Dense UI Speed
SimDex app
04 BUILT

SPUF

HWID / TPM Kernel-Level Spoofer

Hardware identity spoofer with kernel driver integration. Deterministic seed-based spoofing across 107 identifiers — disk serials, SMBIOS, GPU, MAC, registry, EFI, and TPM 2.0 emulation. Anti-forensics pipeline with automated trace removal.

WPF .NET 10 C# Kernel Driver HWID TPM
SPUF
K R U E G E R
05 LIVE

SwiftBill

SaaS Invoice Generator

Freemium invoice generator built with Next.js 16 and Supabase. Create, manage, and export professional invoices as PDF. Stripe subscription billing, Google OAuth, live preview, and dashboard analytics.

Next.js 16 Supabase Stripe SaaS
swiftbill.app
12INVOICES
$4.8KREVENUE
$890PENDING
#0012
#0011SENT
#0010DRAFT
06 LIVE

TapCard

Digital Business Card Platform

Digital business cards with NFC tap and QR sharing. Real-time analytics, contact capture, instant updates, custom domains, and Apple/Google Wallet support. Free, Pro ($5/mo), and Teams ($8/user/mo) tiers.

Next.js NFC QR SaaS
TAPCARD
KRUEGER
Product Engineer
[email protected] tapcardapp.com/krueger Pacific / Remote
07 LIVE

TapBio

Link-in-Bio Platform

Link-in-bio platform for creators and professionals. Unlimited links, custom themes, click analytics, and mobile-first design. Free, Pro ($5/mo), and Teams ($8/user/mo) tiers. Built with Next.js and Tailwind CSS.

Next.js Tailwind CSS Analytics SaaS
K
@KRUEGER
Product Engineer · Builder
TAPBIO
08 LIVE

SwiftLead

Lightweight CRM

CRM built for freelancers and small teams. Contact management, visual deal pipeline, activity timeline, smart reminders, CSV import/export. SwiftBill integration for deal-to-invoice workflow. Free, Pro ($9/mo), and Teams ($15/user/mo).

Next.js 15 Supabase CRM SaaS
app.swift-lead.net
128CONTACTS
24DEALS
$14KREVENUE
LEAD
Acme Co
$2.5K
Nova Inc
$1.8K
CONTACT
Bolt Labs
$4.2K
PROPOSAL
Spark IO
$8.5K
WON
Apex Ltd
$6K
Vex Co
$3.2K
09 LIVE

VFX Studio

Interactive WebGL Scene Playground

Type a prompt, get a scene. Real-time WebGL playground with 14 shapes, 11 palettes, 8 style packs, 7 render engines, and a custom GLSL fragment shader editor. Audio-reactive (mic or upload, with Web MIDI binding), camera path recorder, post FX stack, and one-click PNG / WebM / GIF export. State persists in localStorage and shares via URL hash.

WebGL Three.js React GLSL Audio-Reactive Web MIDI
VFX > cyberpunk portal, beat-burst particles 60 FPS
10 ARCHIVED

Kineo

Guided Wellness Platform — Discontinued

Former project. Browser-first PWA with account sync, structured health workflows, coaching, nutrition, and scanner surfaces. Development discontinued — skills carried forward.

PWA Health Coaching Installable

Six rules that shape every release.

Doctrines learned from shipping ten products solo. Some hold across the field; some are mine. All of them are non-negotiable.

01 / Release

Ship behind flags.

Every meaningful change lands gated. Production is opinionated; rollouts are not. Reverting a feature flag beats reverting a deploy.

02 / Performance

Measure before you optimize.

No optimization without a baseline. Numbers beat instincts; instincts beat unmeasured optimizations that ship for no one.

03 / Stack

Prefer boring tech.

Postgres + Node will outlive the framework du jour. Reach for novelty only when it pays its tax in capability or speed.

04 / Surface

Own the full stack.

From kernel driver to landing page. The seams between engineers are where the bugs live, and where the experience falls apart.

05 / Quality

Release-ready by default.

If it can’t ship today, it isn’t done. Half-state is debt. Branches that don’t merge in a week were never going to.

06 / Judgment

Optimize for ambiguity.

Writing code is the easy part. The hard work is deciding what to build, what to delete, and what to leave alone.

What I’ve actually shipped with.

Not a tag cloud of buzzwords — a working register of tools used in production code, with proficiency calibrated against shipped surface area.

Languages

TypeScript / JavaScript
All web surfaces · 6+ years
C# / .NET
SPUF · WPF · .NET 10
SQL (Postgres)
Daily · transactional + analytical
C / Kernel
SPUF kernel driver · WDK / WDM
GLSL
VFX Studio shader editor
Python
FastAPI services · ReportLab PDF

Frameworks & Libraries

React / Next.js
SwiftBill / SwiftLead / TapCard / TapBio
Three.js / @react-three/fiber
VFX Studio · WebGL pipelines
Node / Express
Rippet provably-fair engine
FastAPI
SimDex market services
React Native / Expo
Kineo PWA / mobile flows
Vite / Webpack
Build pipelines · lazy chunks

Infrastructure

Cloudflare Pages / Workers
Edge deploy · security headers
Supabase / Postgres
Auth · RLS · transactional schema
Stripe
Subscription · one-time · webhooks
Render / Vercel / Railway
Multi-service deploy + cutover
Custom DNS / TLS / Domains
Production cutover playbook
CI/CD (GitHub Actions)
Build / test / deploy pipelines

Practices

System / API design
REST · webhooks · auth flows
Performance engineering
Profiling · bundle · render perf
Provably-fair / cryptography
HMAC-SHA256 commit/reveal
Real-time / WebSockets
Live chat · betting feeds
Browser QA (Playwright)
E2E · visual regression · nav
Product / interface architecture
Routes · states · release polish

Five steps. No detours.

The loop that takes a product from blank canvas to live URL. Same shape whether the surface is a SaaS dashboard, a kernel driver, or a WebGL playground.

01
Frame

Name the problem in one sentence. Decide what a finished version looks like before opening an editor.

02
Architect

Sketch routes, data shape, state boundaries, deploy surface. Boring tech wins by default.

03
Prototype

Build the smallest end-to-end slice that proves the loop. Visible UI on day one, not week three.

04
Ship

Deploy behind a flag, custom domain, security headers, monitoring. Production from the start.

05
Operate

Measure usage, fix sharp edges, write the changelog, hand off the runbook. The work isn’t done at deploy.

The day-to-day toolkit.

Frontend React, Next.js, TypeScript, Vite, Three.js, Tailwind
Backend & Data Node, Express, FastAPI, Postgres, Supabase, Stripe
Infrastructure Cloudflare Pages, Render, Vercel, Railway, custom DNS
Native & Kernel .NET 10, WPF, C#, WDK / WDM driver, MVVM

Currently available for select work.

Looking for product, frontend, or release-system work where the interface, the infrastructure, and the polish all carry weight equally.

[email protected]

GitHub and LinkedIn are private — happy to share build context, architecture diagrams, or commit history on request.