A website for an auto repair shop, on its own hardened server
A website that takes customer requests, on a small server locked down and checked across three restarts.
$ ls work/ --security
Work
What I was asked to fix, what I changed, and how the result was checked, with the numbers. Clients are named only with their written permission.
Case studies
Remote access without opening admin consoles to the internet
Every admin console reachable only from the office network or over WireGuard, and a tested way back in when the firewall locks me out.
One front door for many sites: a reverse proxy with a certificate per name
One public address and one front server for 20 site and app names: TLS ends at the front server, and requests for apps on the second server go over the LAN.
Two Linux servers hardened in four tiers, measured before and after
Key-only SSH, growing bans, audit logging, kernel lock-down and intrusion filtering on two servers, scored with Lynis before and after.
Email authentication for a small domain: test the mail path before changing DNS
Tested how a domain’s mail is really delivered before choosing SPF, DKIM and DMARC settings, then published a strict SPF record and a DMARC record that reports.
client = work for an SD Tech client, described without names. lab = my own servers, where a change is tried before it touches a client system.
Lab notes
I run a small production estate for my own work. New tools run there before they touch a client system. These notes name tools and results, never machines, addresses or client details.
- Private models on a laptop. A 36 GB Apple Silicon laptop runs a 35B mixture-of-experts model offline at conversational speed.
- Detection engineering. Behavioural detection without signatures, tested in the lab.
- Source code. An endpoint agent and console I published under the AGPL-3.0 stays downloadable here, with its checksum, until it moves to its new home. Download the source archive
LLM Chat, a private assistant on my own hardware · Notes for owners
Have something like this on your plate?
Describe it in a line or two. I reply within two business days.