Public Code

• Linux-Home
  • This is a repo I have cultivated over the last ~15 years. The more I hone it the faster I can have a brand new RHEL machine up and running how I want it. At this point I think I'm down to less than 20 minutes.
  • Soon to come is an OSX-home.
• LaTeX Build Container
  • The PDF resume you see below is built with LaTeX, and I needed a way to easily build when I want. So I made a container that can do it for me.
• Tech Notes
  • These are notes that I keep for quick access to past things I have learned.
  • There are good nuggets in there:
    • SSH
      • I figured out a way to hijack an ssh connection, which I think has been patched since figuring this out.
    • Insert a layer into a built container
      • For some security testing I was doing, I wanted to figure out if I could insert a layer into a container surreptitiously. I figured out how to insert a layer, but it did change the final checksum.
      • There are reasons I can think of to want to do this but I've never found the right usecase.

Brock Renninger

Littleton, Colorado

Career Summary

DevSecOps Staff Engineer and Practice Lead with 15+ years of hands-on infrastructure and platform experience. Engineering is the daily work — architecture, delivery, and technical direction across multiple concurrent programs. On top of that, I serve as practice lead for a 30+ engineer DevSecOps organization: owning annual performance reviews, running a mentorship program built from scratch, and acting as the primary interface between the practice and executive leadership.

Technical Foundation

AWS, Azure, Ansible, CI/CD (Gitlab/Github), Claude (inc. MCP’s), Consul/Vault, git, Kubernetes (EKS/RKE2), OCI (Docker/Podman), PostgreSQL, Terraform/Tofu

Languages

C, Go, Python, Bash

Linux

RHEL and Debian based systems (15+ years)

Professional Experience

DevSecOps Staff Engineer & Practice Lead Mar 2017 – Present

SigmaDefense

DevSecOps Practice Lead 2024 – Present

• First called to design and develop solutions for high-profile projects requiring rapid turnaround or architectural direction.
• Primary interface between the DevSecOps practice and the Director of Engineering.
• Primary advocate and escalation point for 30+ DevSecOps engineers across multiple concurrent programs.
• Own annual performance reviews for all tech leads across the practice.
• Maintain a regular cadence with every program manager, and tech lead, while also staying personally connected with a majority of the engineers.

Project Architect & Tech Lead for teams of 2-6 people 2019 – Present

• Set engineering direction across build, test, and delivery for multiple concurrent programs.
• Defined and built environments using Kubernetes on bare metal, virtual, and cloud infrastructures.
• Built automated CI/CD pipelines for ATO approvals; managed the process of iterating forward while snapshots awaited sign-off.
• Set team expectations, created tasking, tracked progress, and reported to customers.

Developer

• Designed hub and spoke architectures on bare metal, AWS, and Azure.
• Containerized services, automated manual processes using CI/CD and Ansible, refactored codebases to reduce build times.
• Leveraged AI-assisted development (Claude Code, and MCP’s) to build and accelerate CI/CD tooling across programs.

Director of Mentoring

• Built a structured mentorship program from scratch — curriculum, mentor/mentee matching, expectation-setting, and ongoing facilitation.
• Created a sustained safe space for engineers to surface frustrations, ask hard questions, and grow outside the management chain.
• Mentor managers, tech leads, and junior engineers across the practice.

Stakeholder & Customer Interface

• Conducted recurring education sessions for Navy Captains and Admirals — built from the ground up around a questions-first, no-ego culture.
• Translated engineering realities into executive context and program-level expectations in both directions.

Software Engineer III 1 year

ReadyTalk (acquired by PGi) – Foxden.io

• Designed and deployed Docker-based Jitsi video conferencing infrastructure for both the UI and server components.

Sr Software Engineer

Lockheed Martin

Innovation Manager

Technical interface to sub-contractors; coordinated engineering direction across organiza- tional boundaries.

Engineering

Lead designer and developer for an ATO-approved PL-5 cross-domain device — architecture built around three layers of trust: hardware, operating system, and data transfer. Designed a secure, multi-networked data transfer program in C using simultaneous wired and wireless technologies. Built, packaged, and maintained a custom Linux OS for a distributable VoIP/GSM telephony prototype using Asterisk.