CAD & mechanical design
Solid modeling, assemblies, and design-for-manufacturing for prototypes and small runs.
Layout lab
Portfolio layout lab
Building blocks on Heff.world design tokens. Production copy lives on services, cloud hubs, and Keystatic collections.
stale — Not linked from the main navigation—listed on the site overview for QA.
Build with clarity. Ship with confidence.
I help teams with web and product engineering, embedded software, and mechanical design. Philadelphia-based, with Delaware roots; working with clients everywhere.
About
About Me
With almost a decade of experience in engineering design, I work the whole stack: CAD and mechanical design, embedded software, and modern web platforms. I focus on clear communication, practical tradeoffs, and shipping work you can maintain.
Software engineering
Building modern, responsive websites using the latest technologies.
Embedded & firmware
Bare metal software solutions, custom SBC stacks, and more. Extensive experience soldering multi-board assemblies and custom modifications including piggybacks.
Featured Projects
Explore some of our recent work and creative solutions
Proxmox Homelab Cluster
Three-node Proxmox cluster on Dell OptiPlex 7040s — VM hosting, Traefik + Caddy reverse proxy, and self-hosted services for Heff properties.
Software
View Project Details 
Stagea Stuff Platform
Monorepo for Nissan Stagea owners — parts discovery, fitment notes, and community tooling born from JDM import logistics pain.
Software
View Project Details heff-shop Saleor Monorepo
Multi-channel Saleor storefront — platform and forked storefront submodules, Docker smoke tests, and GraphQL channel wiring.
Software
View Project Details My Process
A streamlined approach to bringing your vision to life
1
Initial consultation
I align with you on goals, constraints, timeline, and what “done” looks like for your project.
2
Plan & tradeoffs
I propose a lean path: milestones, risks, and what to validate first - before writing too much code or CAD.
3
Build & iterate
Short delivery cycles with demos and feedback. You stay in the loop; I adjust as we learn.
4
Test & harden
Exercise the real failure modes: performance, edge cases, and integration points that matter.
5
Ship & handoff
Deploy, document, and transfer ownership - or keep a light retainer if you want ongoing help.
Engagement model
Flexible consulting - scoped to your risk and timeline
MonthlyYearly (Save 20%)
Consulting
Illustrative retainer-style numbers; real quotes depend on scope
$300 /mo
$3000 /yr
- Discovery + written scope (what we’re building and why)
- Iterative delivery with demos
- Clear handoff and documentation
- Async updates + scheduled checkpoints
- Optional ongoing support after launch
- Honest “no” when something isn’t a fit
What people are saying
"Solid scoping, steady demos, and documentation we could actually hand off. No bait-and-switch on stack or timeline."
Geoffrey
Product lead
"Firmware and web moved together - fewer integration surprises than we are used to on hardware projects."
Connor D
CTO, startup
"Clear tradeoffs, no mystery months. We always knew what was in scope and what was next."
BowTiedFocus
Founder
"Practical CI and test discipline without boiling the ocean. Good fit for a small team."
Aniket P
Engineering manager
"Mechanical and software constraints were discussed in the same room - saved us rework."
David G
Hardware lead
"Responsive, pragmatic, and allergic to unnecessary process. Exactly what we needed."
Damiano L
ConsultantShare your experience
Verified members can submit a testimonial. Submissions stay in draft until an admin approves them in Keystatic.
Sign in to submit a testimonial. Sign in
Latest Insights
Explore our thoughts on design, development, and creative processes
Local agentic AI — Mac Mini harnesses, a 4090 worker, and one Obsidian skill vault
JJ Heffernan
•Jul 6, 2026
OpenMANET radio buildout: pace car mesh comms at Watkins Glen
jheff.media-site, from boilerplate fork to a modern Rust media stack
JJ Heffernan
•Jun 19, 2026
MakerWorld BOM to McMaster: building a rule-based hardware matcher
JJ Heffernan
•Jun 8, 2026
Animal Garage: building a headless automotive storefront from scratch
JJ Heffernan
•Jun 7, 2026
Revopoint POP 2 vs Shining 3D Einstar (wired): scanners, software, and real-world tradeoffs
Contact
Let's talk
Tell me what you're building, your timeline, and what success looks like. I'll follow up with questions, a proposed scope, or a quick call. Whichever fits.
- Availability
- Monday – Friday (US Eastern). Remote availability with cloud-first delivery. On-site is by appointment only.
Our Location
Philadelphia area, USA
Send a message
FAQ
Frequently Asked Questions
Find answers to common questions about our services and process
Typical work spans web apps and internal tools (TypeScript, APIs, Astro or similar), firmware and bring-up on embedded targets, and CAD or mechanical design when the problem crosses hardware and software. If it is not a fit, I will say so early.
We start with a short discovery call and a written scope: milestones, risks, and what success looks like. Then we iterate in small loops with demos, feedback, and adjustments so surprises stay small and decisions stay informed.
Most work is remote and async-friendly, with scheduled checkpoints. On-site or lab time can make sense for hardware bring-up, fixtures, or tight integration weeks. We can plan that when it matters.
By default you own deliverables paid for under the agreement. Details belong in the contract (NDA, license, and handoff). I am happy to align with your legal or procurement process.
You work with me. For larger efforts I may bring in trusted collaborators with your approval, but I stay accountable for integration and quality.
Use the contact form on this site or reach out on LinkedIn. A short description of the problem, timeline, and constraints is enough to start a conversation.