01
Software development
Web applications and backend systems in Elixir, with interfaces built in Phoenix LiveView, plus architecture reviews and audits of existing codebases.
> software engineering · independent & b2b
Technology that takes flight.
Independent software and infrastructure engineering, built on Elixir. Simple, reliable, and made to scale.
// companies I have worked with
9+years in backend engineering
8+years building Elixir/OTP systems
$2B+freight payments on event-sourced systems
// 01 services
Services
02
Financial & event-driven systems
Payment flows, ledgers and workflows modeled as events, so every change is auditable and can be replayed.
03
Cloud & infrastructure
Secure, observable and cost-aware infrastructure that keeps your products fast and available.
// 02 technologies
Technologies
Elixir, PostgreSQL, Docker, Terraform and Google Cloud make up the main stack, though not the only tools in use. Select an item to see how it fits together.
// elixir ecosystem
// 03 approach
A calm, deliberate way of working.
Simple
Anything not needed is removed. Fewer moving parts means fewer things that can break.
Reliable
Tested, monitored and documented, so your systems keep working when it matters.
Transparent
Clear scope, honest timelines and regular updates from first call to launch.
Built to last
Foundations designed to grow with your business instead of being rebuilt every year.
Async by default
Time zones matter mostly for meetings. The work itself can be done from anywhere, for anywhere, through written plans, pull requests and short updates. I’m flexible with my hours for live calls.
// 04 how I build with AI
AI writes much of the code. I own every line that ships.
01Done by me and AI agents
Plan
I design first: the data flow, boundaries and risks, drawn as diagrams before any agent is involved. Then an agent challenges that brief with adversarial questions, and I decide what changes until the plan is agreed. Plans that need team input are published for review on Send Artifact.
02Done by AI agents
Build
Firstmate splits the plan into focused tasks, each handled by a worker in an isolated Herdr workspace. Model and effort are matched to each task’s complexity, and rtk and gh-axi keep tool output lean, so tokens go to the problem rather than overhead. Workers follow TDD, guided by my rules and Elixir skills.
03Done by AI agents
Verify
Each worker runs end-to-end QA on the development environment, covering the happy path and a failure path, then reports the evidence and stops before committing.
04Done by me
My review
I read, question and refine every diff. Nothing is committed without my approval.
05Done by AI agents and me
Gate
Every push passes through no-mistakes. In a disposable worktree it rebases, runs an AI code review, tests, documentation checks and linting, and fixes mechanical issues. Anything that changes intent comes back to me.
06Done by AI agents and me
Ship
The worker opens the pull request and requests team review. Agents resolve mechanical review comments, and larger changes come back to me. I run manual QA on staging before every release.
07Done by me and AI agents
Learn
Every mistake becomes a lasting safeguard: a hook that blocks it, a skill for that type of task, or a rule every session follows. The whole setup is versioned and tested in CI.
Elixir is my main stack, and I also take on Ruby and Python. I don’t take work in stacks I can’t review well, because AI-written code is only as good as the person checking it.
// 05 contact
Let’s build what’s next.
Describe the project and get a clear next step in reply, within one business day.
- 01ReplyQuestions, or a clear next step.
- 02CallA short call to agree on scope.
- 03ProposalWritten scope, timeline and price.
~ Happy to sign an NDA before you share details.
// availability · Brasília time (BRT)
Top row is me, 09–18.overlap with my hourstheir 09–18off hours