██╗ ███████╗ ██████╗ █████╗ ██████╗ ██████╗ ███████╗██╗ ██╗
██║ ██╔════╝██╔═══██╗ ██╔══██╗██╔══██╗██╔══██╗██╔════╝██║ ██║
██║ █████╗ ██║ ██║ ███████║██████╔╝██████╔╝█████╗ ██║ ██║
██║ ██╔══╝ ██║ ██║ ██╔══██║██╔══██╗██╔══██╗██╔══╝ ██║ ██║
███████╗███████╗╚██████╔╝ ██║ ██║██████╔╝██║ ██║███████╗╚██████╔╝
╚══════╝╚══════╝ ╚═════╝ ╚═╝ ╚═╝╚═════╝ ╚═╝ ╚═╝╚══════╝ ╚═════╝
abreusleo :: machine-readable index
a plain-text mirror of this portfolio for AI agents, crawlers,
and humans who prefer it raw.
generated from the same config the 3D room reads, so the two
cannot drift.
── PROFILE ───────────────────────────────────────────────────
name ............ Leonardo Santos Abreu
role ............ Software Engineer Backend
company ......... Pismo, a Visa company
location ........ Rio de Janeiro, Brazil
Backend software engineer working on core banking and card
processing at Pismo.
Day to day: services in Go, C# (.NET) and Python, with gRPC,
Kubernetes, Amazon EKS and Istio.
Outside work: this portfolio, a survival game, and six
applications running on one VPS.
── EXPERIENCE ────────────────────────────────────────────────
Backend software engineer at Pismo since 2024, the Brazilian
core banking and card processing platform that is now part of
Visa.
It is the layer banks and fintechs use to issue cards, hold
accounts and process transactions: the kind of system where
the books have to balance, at the volume that makes balancing
mean something.
Before that, three years and eight months at Stone Age, from
intern to engineer, on a SaaS that had to scale without
falling over. Everything else I build happens outside working
hours.
Software Engineer Backend
Pismo · Full-time · Remote
Sep 2024 — Present
· Core banking and card processing platform, part of Visa.
Software Engineer
Stone Age · Full-time · Remote
Jan 2023 — Aug 2024
· Scalable SaaS product: new features, shared libraries,
stability against client SLAs.
· Led the migration of a refactored service with zero
downtime.
· Fixed a memory leak triggered by dynamic tenant
configuration updates.
· Cut latency on a critical flow by 20% by removing
redundant database calls and cold starts.
Software Developer Intern
Stone Age · Internship
Jan 2021 — Dec 2022
── EDUCATION ─────────────────────────────────────────────────
BEng, Computer Engineering
Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio)
Jun 2017 — Jul 2023
· Final thesis: basketball shot-map visualisation, in
partnership with Flamengo (NBB).
· Delivered a website and two new visualisations, replacing
existing MATLAB ones.
Vocational course, Software Development
Step Computer Academy Brasil
Jan 2017 — Jun 2020
── AWARDS ────────────────────────────────────────────────────
· 1st place — Startup Weekend, Três Rios (car wash delivery app)
── STACK ─────────────────────────────────────────────────────
languages ....... Go, C# / .NET, Python, TypeScript, Lua
infrastructure .. Kubernetes, Amazon EKS, Istio, Docker, Terraform
practice ........ gRPC, Locust, unit testing, load testing
graphics ........ three.js, WebGL, GLSL, Vite
── APPLICATIONS ──────────────────────────────────────────────
Six applications on one server. Hub is the front door and the
other five live behind it, with no login of their own.
[01] Hub — Sign-in and the way between the tools
One account for every tool on the server. You sign in
once and land on a portal showing what you can open, with
no second login on the way in.
It is also where accounts are created and revoked.
Stack ........... Go · Postgres
Status .......... 62 commits · in use
[02] Orb — One place for the feeds, videos and newsletters
Everything you follow in one place: sites over RSS,
YouTube channels, Twitch and Kick streams, Reddit
communities and newsletters that arrive by email.
Video lands on a timeline that separates what is live,
what has aired and what is scheduled. Clean reading mode,
publish alerts, and your existing list imports over OPML.
Stack ........... TypeScript · SQLite
Front ........... PWA
Status .......... 99 commits · the busiest
[03] Fin — Spending, read from the real bank data
Reads your bank statement and shows where the money went:
by category, by month, and what moved since last month.
Including the subscriptions nobody noticed.
Deliberately deterministic, with no language model in it.
Stack ........... Go · SQLite
Front ........... React · TypeScript · three.js
Instance ........ one per person
[04] Cal — Calorie tracking that reads a photo
What you ate today, adding up against the target. Entry
can be a photo of the plate or a sentence, and the app
estimates portion and calories from it.
Weight and measurements are tracked over time in the same
place.
Stack ........... Go · Postgres
Status .......... 18 commits
[05] Fut — Football tactics board, online
A football tactics board that works online. It is for
picking the side, walking through a move and settling
where everyone stands, with each of you at home.
The touchline board, moved onto the internet. Instead of
scribbling on one and hoping everybody read it the same
way, you all open the same pitch and watch the move from
whatever angle you like.
Stack ........... Go · WebSocket · three.js
Status .......... 73 commits
[06] Lvl — Runs the game servers
Starts and stops the house game servers without anybody
opening a terminal. Shows who is on, what the box can
take, and backs the world up.
It serves Minecraft, Factorio and Project Zomboid.
Stack ........... Go · Docker
Games ........... Minecraft · Factorio · Zomboid
Status .......... live
── PRODUCTS ──────────────────────────────────────────────────
Two things that exist outside the personal server: a hospital
SaaS and a game being built.
[01] Bios Health — Operating theatre SaaS
A multi-tenant platform for running a hospital operating
theatre in real time. It follows the whole patient
journey: scheduling, pre-op, surgery, recovery and
discharge.
All of it becomes a live board for the executive team, in
place of a spreadsheet and a monthly report. PDFs are
read by computer vision and turn into structured data on
their own.
Backend ......... Go · MySQL
Frontend ........ Next.js · React · TypeScript
Infra ........... Terraform · Kubernetes
Status .......... 1,000+ commits
[02] Surviving — Survival game
A first-person post-apocalyptic survival game with
zombies, built for asymmetric multiplayer. The line that
sums it up comes from its own design document: survive a
world that wants you dead — the zombies, the environment,
and sometimes the other players.
The loop is reading hunger, thirst, temperature, health
and sanity, going out to explore and loot, crafting and
repairing, and hardening a position before night. Scarce
resources and permanent death. PvP exists but is never
encouraged.
Engine .......... s&box · Source 2
Language ........ C#
Status .......... in progress · open repository
── ABOUT ─────────────────────────────────────────────────────
Computer engineer, born in Rio, Fluminense supporter.
In love with sport, competition and games. The thread running
through them is the contest, the format that ends with a
score.
I live between studying, competing and having fun.
Degree ................. Computer Engineering
Based in ............... Rio de Janeiro
Club ................... Fluminense
Away from the keyboard . sport · competition · games
── QUOTE ─────────────────────────────────────────────────────
"The biggest things in life have been achieved by people who,
at the start, we would have judged crazy. And yet if they had
not had these crazy ideas the world would have been more
stupid."
This line was my wallpaper for four years.
── LINKS ─────────────────────────────────────────────────────
github ........ https://github.com/abreusleo
linkedin ...... https://www.linkedin.com/in/abreusleo/
human view .... /
── FOR_AGENTS ────────────────────────────────────────────────
llms.txt ...... /llms.txt
human view .... /