Consultant · Apple Silicon ML & Python

Adrian Szczepański

Apple Silicon ML — from research code to shipping product.

Open-source maintainer of ComfyUI-CoreMLSuite — one of the few tools running Stable Diffusion through Core ML on the Apple Neural Engine, 1.5–2× faster on M2 Pro, maintained since 2023. Eight years of production Python engineering before that.

Book a free discovery call hi@aszc.dev

How I can help

On-device ML: Core ML, MLX, ANE

You have a model that works. Now it needs to run fast, on-device, in a real macOS or iOS app — or in a creative pipeline on Mac hardware. I handle the Core ML and MLX conversion, the quantization decisions, the attention implementation choices, and the Python or Swift glue that holds it all together.

This is where my open-source work gives you the most leverage. Past examples: 1.5–2× diffusion speedup via ANE optimization, batched inference pipelines, custom node ecosystems for creative AI tooling. My published benchmarks show the ANE running the SD1.5 UNet at 6–7× lower energy than GPU/MPS at the same speed — the kind of measurement that decides where your inference bill goes.

Productized offer — performance audit. Benchmarks on your hardware, a written report, and prioritized optimization paths. 1–2 weeks, fixed scope.

Ask about it

Production Python backends

API design, data pipelines, deployment, observability — the boring-but-essential work that makes a system you can actually rely on. I've migrated enterprise codebases from Python 2 to 3, built a market-making bot, designed CI tooling that outlived my time on the team.

Technical advisory & code audits

When you need a second pair of eyes on a critical architectural decision, a written review before committing to a direction, or an honest assessment of a codebase you've inherited. Half-day to multi-day engagements with a written deliverable.

Not sure where to start?

Book a free 30-minute discovery call — bring the problem, and I'll tell you whether I can help and what it would take. If we don't fit, I'll say so and point you to someone who does.

Selected work

ComfyUI-CoreMLSuite (open source)

A set of custom nodes that brings Apple Neural Engine acceleration to ComfyUI workflows. 1.5–2× speedup on M2 Pro for 512×512 diffusion. Supports SDXL, LCM, ControlNet, LoRA baking, and the full Stable Diffusion conversion pipeline. Used by the Apple Silicon AI community since 2023.

LPIPS perceptual distance from the fp32 PyTorch reference after converting each Stable Diffusion component to Core ML: VAE 0.003, CLIP 0.038, UNet 0.253, full pipeline 0.251. The UNet accounts for essentially all the drift.
Converting the VAE and CLIP to Core ML is near-lossless; the UNet carries essentially all the perceptual drift — so the full pipeline drifts no more than the UNet alone. Full ablation →
A ComfyUI workflow using the CoreML nodes: LCM converted to Core ML, driven by ControlNet, sampled on the Apple Neural Engine.
LCM → Core ML conversion with ControlNet, sampled on the Apple Neural Engine.

Independent products

blzr — a node-based editor for the Web Audio API. Aims to cover the full API surface through a React Flow interface, extended with utility nodes (MIDI), custom AudioWorklets, and keyboard input. Built for fast prototyping of audio engines that run entirely in the browser.

A blzr patch: a seven-oscillator supersaw with per-voice stereo panning, lowpass and highpass filters, and reverb, wired entirely from Web Audio nodes.
A seven-voice supersaw — detuned oscillators, stereo spread, dual filters, reverb — running entirely in the browser.

Client work

Alongside open source, I take contract engagements — usually as the engineer who joins ML, software, and hardware components into one working system.

Autonomous drone platform (contract, 2025–2026)

Python and integration lead on a multidisciplinary team (flight control, computer vision, hardware). Built a low-latency image-recognition pipeline on Raspberry Pi + Hailo tuned for closed-loop flight control; designed training scenes in NVIDIA Isaac Sim and a minimal custom simulator to validate control logic before hardware deployment; drove YOLO fine-tuning for precise feature localization. I was the one person responsible for making the full software+hardware pipeline work end-to-end.

AI product delivery (via xfaang, 2024–2025)

Deployed and hosted an emotion-recognition-from-video model behind a web application; built a voice-activity-detection component for audio analysis; extended a Flask-based API with service clients automating business workflows. Production AWS throughout (Lambda, ECS, EC2).

From the log

I document the engineering — benchmarks, failed runs, exact versions — at log.aszc.dev. Recent findings:

About

I've spent eight years building software in places where it actually has to work — enterprise networking at CodiLime, market-making at Igoria, integration APIs and AI product delivery at Xfaang, edge ML on an autonomous drone platform. I've migrated codebases from Python 2 to 3, mentored junior engineers, and built tooling that outlived my time on the team.

In 2023 I started ComfyUI-CoreMLSuite because Apple Silicon ML acceleration was a frontier no one had made accessible to non-specialists. It's a project I still maintain — and the foundation of how I work with clients today.

My instinct is for systems that are stuck — slow, brittle, or unclear — and for figuring out which single lever actually moves them. That's the work I want more of.

Remote, based in Poland (EU/CET). Working with clients internationally.

Contact

The shortest path: hi@aszc.dev — I respond within one business day.

Or skip the email back-and-forth: book a free 30-minute discovery call .

Limited availability through Q3 2026.