Lachlan Cox

G'day, my name is

Lachlan Cox

lcox74@outlook.com

Software developer at Tillered, where I write Go for the network layer and occasionally give myself new footguns to enjoy later. Outside work I write about software, self-hosting, and whatever most recently nerd-sniped me, usually after a rabbit hole I told myself would take an afternoon.

worked at
Senior Software Developer & Security Officer Nov 2021 - Present

I wrote Tillered's network-acceleration core, including an automated QoS layer that tunes congestion-control to live link conditions. I also rebuilt the product into a decentralised, airgapped system that can be driven by a custom infrastructure-as-code format, supporting up to a hundred nodes that self manage and reconcile state between each other. Along the way, I wrote a custom WireGuard implementation that adds layer-2 bridging ontop of the layer-3 protocol; a host firewall and routing built ontop of kernel netlink and nftables; cryptographic licensing systems, and offline-capable OAuth + OpenID Connect (OIDC) provider with MFA. I've also had to build and design the systems/pipeline to ship the product with custom RHEL images, terraform deployments and designing/building the active company website. I also served as Director from 2022 to 2026.

Go / WireGuard / CRDTs / Protobufs / nftables / AWS / Terraform

tillered.com ->
Software Engineer Jul 2023 - Jul 2024

Worked on embedded and intelligent-transport work for roadside deployments. Reverse engineered low-level sensor hardware where the vendor APIs fell short, wrote the software to drive it and process the raw data, and built the backend for multi-site rigs of sensors, cameras, and signage running over genuinely terrible comms. Also prototyped a machine-vision pipeline that classified vehicles from roadside cameras, plus a Raylib labelling tool to feed it training data.

Go / embedded / Modbus TCP / machine vision / Raylib

hyperiontechnology.com.au ->
Software Developer Apr 2019 - Nov 2022

Worked as a solo dev for a team of financial advisers. Migrated thousands of records out of legacy CRMs into Salesforce with an automated validation pass to prove nothing was lost or corrupted along the way, designed a custom client-lifecycle pipeline in Lightning Web Components, and built a React + Flask tool that bundled client documents for review-and-sign with programmatic PDF signing and a full audit log.

Salesforce / Lightning Web Components / React / Flask / Python

Automation Engineer Jun 2019 - Mar 2022

Worked in a team helping with devops and security on their production powershell applications and automations. Then worked as a solo developer when they found out I knew how to write C#.NET when they didn't. This put me on an internal automation portal project for technical sales staff, wrapping Nokia's NFM-P API over both REST and SOAP. It exposed provisioning of layer-2 Epipe and layer-3 VPRN services through a clean frontend, replacing the manual NFM-P workflows the team had been doing by hand via calls and emails with NSP support.

C#.NET / React / Nokia NFM-P / REST / SOAP

interactive.com.au ->

Current Quest

lachlan@localhost
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class Fullstack Warlock
patron The Network Layer
langs Go, JavaScript, Lua
education BCompSc (Prog. Languages), UQ (2023)
alignment Pragmatic Evil
status Permanently caffeinated
weakness naming things, cache invalidation
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In Progress

Senior Software Developer at Tillered

Building network acceleration software that optimises TCP over long-distance links at the infrastructure layer, so any workload moves data faster with no application changes.

Remote, Australia Global team Networking + Go

Writing

11 posts
~$ cat blog/2026-06-numpy-in-go.md # latest

Smuggling NumPy Into Go

2026.06.25 · 11 min read

Calling NumPy from Go turns out to mean smuggling a whole CPython interpreter into your binary. So I did, and then made it earn its keep.

Read the post ->