John Lonergan
// software engineer · hardware hacker · husband · dad · London, UK
I grew up in the 1980s pulling apart anything with a circuit board and teaching myself electronics and assembly before I could legally drink. Then software happened — decades of it, building distributed systems for financial institutions in London across Java, Kotlin, Scala, Python, Go and whatever the industry threw at me next.
In 2019 I came back to hardware as a hobby. The SPAM-1 project — a complete 8-bit CPU built from 7400-series TTL logic++, with Verilog accurate simulation, custom assembler, C compiler backend and full toolchain — is what happens when a software architect gets to scratch a 40-year itch.
Still working in London and looking for interesting, gainful opportunities.
Outside of all that: husband, dad, friend, dog owner.
Summer holidays in Ireland
Long summers in Ireland as a child, and as much as possible ever since — beaches, mountains, bogs, sheep, and maybe a bit of surfing if lucky.
Hacking from age 10
Taking things apart to see how they worked — building crystal radios, dismantling toys, TVs, anything with a circuit inside. The curiosity came first; the theory caught up later.
First code, age 15
Programming on a terminal linked to Ford Motor Company's mainframe at school, and on an Apple II Europlus — while also building first electronics projects. The hook was immediate on both fronts.
Self-taught electronics & assembly
Pulled apart anything with chips in it. Taught myself electronics and assembly language. The hardware bug never left.
B.Eng Engineering Science · University of Liverpool
Formal grounding in engineering whilst the side projects kept multiplying.
Defence electronics
First professional role in defence electronics. Engineering electronics for HM navy.
CV →Software developer · Cambridge
Moved into software development in Cambridge. Finding my feet blending my interest in hardware with my growing expertise in software and turning it towards embedded systems and real time machine control systems.
This built a deep, intuitive appreciation for the intersection of hardware and software that never left. How the CPU works, the impact of latency, the challenges of concurrency — mechanical sympathy and principles like KISS came to the fore here and shaped everything that followed.
CV →Solo travel · SE Asia, Australia, NZ, China, Japan
Stints travelling alone across Southeast Asia, Australia, New Zealand, Yangshuo China, and Japan. Including a week in Yangshuo, China — informal English teaching in a rural school, and lovely bike rides through the countryside. Formative in every sense.
Then marketing & insurance industry solutions
Stints in marketing and insurance firms making correlations between customer behaviours and opportunities — an interesting tour of what software actually powers before the era of AI.
CV →Director, Advisory Technology · UBS Investment Bank · London
Technical lead for the bank's strategic CRM and equity research systems. Introduced agile and automated testing practices, built a web application firewall infrastructure, and migrated from a vendor CRM to a bespoke solution across telephony integration, network programming, load balancer management, and analytics.
CV →Director, Global Markets Securities Technology · Bank of America Merrill Lynch
Lead engineer on the BAML securities straight through processing system in the global securities middle office. Transformed the development culture towards automated testing, continuous integration, and frequent delivery. Introduced Scala as the team's strategic language, built a real-time inventory system using event sourcing and CQRS, architected a reverse proxy platform for secure web app deployment, and led a data platform for analytics and machine learning.
CV →Senior Principal Software Engineer / Executive Director · JP Morgan
Engineering lead across a collection of feature teams in Cloud Services, adapting to where the organisation needs senior engineering input. Driving standards, doing code and architecture reviews, and using every available opportunity to develop engineering practices across teams.
CV →Scuba Diving — BSAC 510 CliDive
Years as a member of CliDive (BSAC 510) — where I met Caroline, my future wife. Hundreds of dives around the world followed. Caroline and I celebrated our honeymoon on a diving trip to Micronesia in the Pacific, one of the world's great dive destinations.
Married Caroline
Katie arrived in 2002, then Johnny and Gracie in 2004.
4 weeks in Borneo · with the family
The whole family visiting remarkable natural sites and staying with local families. A humbling and unforgettable experience.
5-week US road trip · National Parks
The whole family, camping all the way — San Francisco, Yosemite, Death Valley, Grand Canyon, Monument Valley, Bryce Canyon, Yellowstone. One of those trips that becomes part of the family mythology.
Total Solar Eclipse · Wyoming desert
A US road trip culminating in a truly extraordinary total solar eclipse viewing with the family in the dry Wyoming desert — one of those once-in-a-lifetime moments. Then on to New York before the return to reality.
Family skiing in Europe
A winter tradition — hitting the slopes somewhere in Europe with the family each year.
Back to hardware — SPAM-1 begins
Rejoined the hardware world and started the SPAM-1 8-bit CPU project on Hackaday. The itch had been waiting 30 years.
Spanish Eclipse 2026
Looking forward to the Spanish eclipse with the family — and more life-building memories.
Building HiFi speakers
Blending a love of audio, electronics, and handicraft — designing and hand-building HiFi speakers from scratch.
Still building, still working
Still coding, still soldering, still writing toolchains from scratch for fun.
SPAM-1 — 8-Bit CPU from 7400 TTL Logic
A complete 8-bit CPU built entirely from discrete TTL 7400-series chips — no FPGAs, no cheating. Full Verilog simulation, custom assembler, C compiler backend (VBCC port), CHIP-8 emulator, NES controller interface, and a growing toolchain. Documented exhaustively on Hackaday and GitHub.
Google Home Max Killer
A kitchen smart speaker out to beat our Google Home Max. The Max nails the countertop form factor and gets plenty loud, but fakes its bass with DSP that overdrives tiny woofers and leans on harmonic tricks to fool the ear — and it all collapses once you push the volume.
Building a sub for my vintage B&W DM4s reminded me there's a whole universe of sound below 70 Hz I'd been missing — so I turned a critical ear on the kitchen. My answer: a similar shallow countertop enclosure (36×22×18 cm vs the Max's 30×20×16), genuinely balanced low end at real volume with minimal DSP smoke-and-mirrors, a sensible build cost, and Google Assistant still on board. Build underway — will report back.
Integrated Circuit Tester
Interactive tester and exploratory tool for logic chips, including tri-state support. Useful in the lab when debugging old ICs.
Dual 7-Segment Hex Display
Two-digit hex display module using a PIC16F18446 microcontroller. Built to act as a debug display for the SPAM-1.
NES Controller Interface
NES gamepad interface for SPAM-1, enabling CHIP-8 game input via original Nintendo hardware. Because of course it does.
VBCC Compiler — SPAM-1 Backend
Porting the VBCC C compiler to target the SPAM-1 instruction set. Writing a compiler backend from scratch to run C on homebrew silicon.
7-Segment Display Module (DM9368N)
Compact two-digit breadboard-compatible display module using the vintage DM9368N decoder driver ICs.
Drinking Horn Renovation
Restoring and renovating a drinking horn — cleaning, re-sealing, and finishing a traditional vessel back to usable condition.
Subwoofer — Tang Band W5-1138
Building a subwoofer enclosure around the Tang Band W5-1138 driver. Speaker cabinet design, construction, and tuning.