AI & backend engineer · Ireland

Nigel Hanlon

Solving problems and learning things.

I build AI systems and the backends they run on. Fifteen years of production software in TypeScript, Node.js and PostgreSQL. These days that means connecting agents to the tools engineers already use, and researching how language models work.

Nigel Hanlon

01 · Selected work

Landmarks along the way.

02 · Toolkit

What I work with.

AI systems

  • Claude Code, agents & skills
  • MCP servers & integrations
  • Retrieval: BM25 + vector search
  • Embeddings & local LLMs
  • Python & PyTorch
  • Experiment design & evaluation

Backend & data

  • TypeScript & Node.js
  • PostgreSQL & PostGIS
  • GraphQL & REST APIs
  • Redis & Elasticsearch
  • SQLite (FTS5, sqlite-vec)
  • React

Infrastructure

  • AWS
  • Kubernetes & Terraform
  • CI/CD, Git & GitHub
  • Sentry & Datadog
  • Incident response
  • Linux

03 · Research

Field notes.

Independent experiments on how language models work. I build the controls before I believe a result, and I publish the ones that fail.

  • The MambaE answer leak

    A state-space model seemed to solve two-hop reasoning. Three controls showed it was reading the answer from the input.

    post-mortem
  • Fast-weight reasoning

    Can a cheap recurrent layer chain facts together in one pass without attention? Three chapters map where it breaks, and one training change gets partway through.

    fast weights
  • Weather nowcasting

    Gradient-boosted trees on one station's hourly readings beat the 1920s barometer rule a cheap weather station uses.

    applied ML
All research →

04 · The route

Fifteen years, charted.

  1. 2022-now You are here

    Contentful Software Developer

    Content-database abstractions on PostgreSQL and performance work, plus the agentic development setup my team uses daily.

  2. 2021-2022

    ENGAGE XR Senior Software Developer

    A new Node.js microservices architecture and the move off a legacy PHP monolith.

  3. 2017-2021

    Nearform Full-Stack Developer

    Client work for public health, construction, publishing and agriculture, from national COVID-19 contact tracing to hackable conference badges.

  4. 2014-2017

    OpenApp Developer & Systems Admin

    Health and geospatial platforms, including An Post GeoDirectory and a patient-data encryption tool.

  5. 2011-2014

    Hanlon IT Independent

    The air-ambulance GIS for Health Atlas Ireland, in service for over five years.

  6. 2008-2009

    OpenApp Systems Administrator

    Where it started.

The full route and the archive →

05 · Bearings

I grew up on a farm in rural Ireland. My dad was a mechanic, and I spent most of my childhood with oil on my hands and grease under my nails, helping him fix farm machinery. It taught me how mechanical things are designed, how they fit together, and how timing can make or break something. It's also why I took apart so many toys as a kid. I was a menace with a screwdriver.

Our first PC was a Packard Bell with a 166MHz Pentium and 8MB of RAM. I saved up for my own, built websites in Word, and then my cousin dropped off a big heavy book called Corel Linux. I installed it and made a huge mess of my PC. Linux back then had no safety rails, but you learned either way. Those nights at a glowing screen well past midnight, feeling triumphant when hello world compiled, are still how I learn.

Richard Feynman said "What I cannot create, I do not understand." That's my brain in a nutshell. I want the why underneath things, and I get there by taking the thing apart and building it again, hopefully a bit better.

I'm autistic, so I don't see the world like most people. Everything is the sum of different parts working together, be that nature, code or the thoughts in our heads. Understanding the world helps me understand myself.

06 · Talks

On stage.

Feb 2020
Top 10 REST API Mistakes and How to Avoid Them Node.js Dublin Meetup
Slides
Apr 2017
Saving Lives with Node.js (and the Air Ambulance Service) Node.js Dublin Meetup
Slides Video

07 · Contact

Building something with AI, or want to talk shop? Email me. I read everything.

nigel [at] mapwolf.net LinkedIn GitHub