Builder · Adelaide, Australia

Stewart Celani

Project Engineer and Developer

Passionate about user privacy. Oddly fascinated by file converters. Building the Tools.FAST network.

Flagship Project

Building the Tools.FAST Network

A constellation of single-purpose utilities on premium .fast domains. One account, shared credits, EU servers. Every tool does one job, does it well, and solves the 80% use case fast. Built on .NET 10, PostgreSQL, RabbitMQ, and Redis — running on a single vertically-scaled server with zero-downtime deployments.

Convert.FAST

165+ converters

165+ file converters across images, documents, audio, video, archives, ebooks, and fonts. 1,000 files per batch.

Compress.FAST

409ms median compression

Smart bulk compression for JPG, PNG, PDF, Word, and PowerPoint. Per-file before/after quality slider.

PDF.FAST

80% PDF reduction

Merge, split, compress, OCR, watermark. Managed PDF compressor built from scratch — no Ghostscript.

Tools.FAST API

165+ API endpoints

Unified REST API across all .fast tools. OpenAPI spec, .NET SDK, API key auth, batch processing, and real-time job tracking.

Zero-Downtime Deploys

8-gate deployment pipeline with RabbitMQ-aware drain. Two instances, one server, no Kubernetes.

Fair Scheduling

Tier-priority weighted round-robin via RabbitMQ + Redis. No user monopolizes the queue.

Privacy-First

EU servers only (Hetzner, Germany). Files auto-delete after processing. No AI training on user data.

Shared Infrastructure

One login, shared credit wallet, unified job queue. Consistent experience across every .fast tool.

Read the full story
Stewart Celani

About

Sysadmin turned developer turned founder

MCSE-certified Systems Administrator turned Software Developer with 15+ years bridging enterprise IT and modern development. As a Project Engineer, I manage infrastructure for 500+ employees by day while building production software that solves real business problems.

My unique position lets me identify inefficiencies firsthand and build the integrations to fix them — from unifying business systems into a single interface to automating warehouse operations with barcode scanners.

Outside of work, I'm building the Tools.FAST network — a constellation of privacy-first file utilities on premium .fast domains.

Adelaide, Australia

Portfolio

Other Projects

From enterprise systems serving 200+ users to open source tools and a classroom monitoring startup that hit $2K MRR.

beamit.to

TypeScript React Node.js Cloudflare R2

Zero-knowledge file transfer. Client-side AES-256-GCM encryption, Cloudflare R2 edge storage, sci-fi word pairing for share keys. If we're hacked, there's nothing to give.

Live Site

GitGen

C# .NET 9 AI

AI-powered Git commit message generator. Multiple providers (OpenAI, Anthropic, Google, Groq, local models), instant switching via aliases, encrypted key storage.

GitHub

Multi-Agent Enterprise AI Chat

Internal
C# .NET Azure AI CQRS

10+ specialized agents (web research, SharePoint RAG, planning, synthesis) orchestrated via CQRS. Multi-provider AI with token-level PowerBI observability.

Enterprise Integration Hub

Internal
React TypeScript TanStack SignalR

Unified interface across ABM ERP, AutoCAD, Strumis, and PowerBI. Bill of Materials with live drawing links, procurement automation, role-based access for 200+ users.

Android Warehouse Management

Internal
Kotlin Jetpack Compose gRPC Room DB

Barcode scanner integration, hybrid offline/online architecture with Room DB + gRPC. Syncs hundreds of thousands of ERP rows for true offline-first operation.

ACCBackup

C# .NET 8

Enterprise backup for Autodesk Construction Cloud. Replaced $6K/year commercial solution. 5x faster — 170+ projects (225GB) nightly in 8 hours.

GitHub

Oversight

Node.js Socket.io MongoDB Python

Real-time classroom monitoring. Chrome extension + Node.js server + Socket.io. Grew to $2K MRR across 10-15 schools through word of mouth alone.

YouTube Demo

ConvertX.to

C# .NET 8 CQRS

Clean Architecture file conversion service. 90+ formats, automatic converter discovery via reflection, 82% test coverage (411 tests). Precursor to Convert.FAST.

GitHub

Writing

Latest Posts

Why I Built Another File Converter (Probably a Stupid Idea)

There are a million file converters on the internet. Here's why I built one anyway — the 10-year backstory, Vue islands on Razor Pages, real-time SSE progress, and an AI-agent-friendly API.

How a Bottleneck, YouTube Video and C# Channels Led to a 3x Faster .NET Backup Tool

How I used C# Channels to build a producer-consumer pipeline that cut a 12-hour Autodesk backup down to 4 hours with 94% pipeline efficiency.

Benchmark: How to use C# Parallel.ForEachAsync for 3x faster bulk file downloading

A BenchmarkDotNet comparison of sequential foreach vs Parallel.ForEachAsync for downloading files from the Autodesk Construction Cloud API.

View all posts