GeezerVison

> "A Vinganca nunca e plena, mata a alma e a envenena." - Seu Madruga

var jonathan = new Developer
{
    Location  = "Itanhaem, SP, Brazil",
    Role      = "Software Engineer",
    Company   = "Derivative Path",
    Headline  = "Software Engineer | .NET · C# · Azure | Backend Architecture (CQRS, DDD, Microservices) | Fintech",
    Core      = new[] { "C#", ".NET", "Azure" },
    Exploring = new[] { "Rust", "Go", "Python" },
    Projects  = new[] { "Compilers", "Game Dev", "Simulation", "Bend", "C11", "WebAssembly" },
    Hobbies   = new[] { "Game Dev", "Orbital Mechanics", "Compilers" }
};

`$ whoami`

Software Engineer | .NET · C# · Azure | Backend Architecture (CQRS, DDD, Microservices) | Fintech. Currently Software Engineer at Derivative Path.

12+ years of experience specializing in .NET and Fintech, with professional .NET development since May 2013. C# and .NET are the core: ASP.NET Core, Entity Framework, Azure, and backend architecture with CQRS, DDD, microservices, and clean architecture.

Actively exploring Rust, Go, and Python for high-performance and concurrent systems. Side projects are learning by building: a C# front-end for LLVM, Bend 2 graphics libraries, C11/raylib and WebAssembly, orbital mechanics, and TypeScript with Astro, React, and ReactLynx.

`$ cat focus.md`

Ship fintech backends: C# and .NET with CQRS, DDD, microservices, clean architecture, and Azure.
Learn by building: side projects turn working applications into guided labs, with readable source, repeatable experiments, and documentation alongside the code.
Build compilers and graphics libraries: compile C# to native code with Roslyn and LLVM, and write Bend 2 graphics and math toward raylib parity.
Explore games and physics: build a platformer and visual level editor, then investigate numerical methods and orbital motion through native and browser simulations.
Compare .NET approaches: study REST/gRPC, EF Core/Dapper, authentication, observability, and Blazor UI behavior through executable examples.
Make projects easy to explore: ship playable demos, Astro documentation, and CI checks that keep published claims aligned with the implementation.

`$ ls ~/projects/active`

Public side projects and learning labs.

csharpc
A C# front-end for LLVM. It compiles C# to small native executables through Roslyn and LLVM, in the same family as clang, rustc, and gollvm.
C# Roslyn LLVM compilers
Source

jonlib
Graphics and math libraries written in Bend 2, working toward raylib 6.0 parity, with differential tests against pinned raylib.
Bend 2 raylib graphics math
Source

super-mango-editor
C11/raylib platformer, visual TOML level editor, and Sandbox School for learning game development.
C11 raylib Emscripten WebAssembly level editor learning labs
Play · Learn

solar-system-simulator
Physics-first orbital mechanics lab with a shared C core for native, WebAssembly, and headless runs; reproducible A/B experiments and a source-backed small-body atlas.
C11 raylib WebAssembly numerical methods Verlet / Euler NASA / JPL data
Simulate · Compare experiments

cpnucleo
Hands-on .NET 10 project-management lab: compare REST/gRPC and EF Core/Dapper, explore architecture tradeoffs, and verify behavior with contract tests.
FastEndpoints PostgreSQL OpenTelemetry Astro TypeScript Docker
Learning paths

blazor-mudblazor-starter
Local-first .NET 10 learning sandbox for Blazor Server and MudBlazor: state, forms, APIs, persistence, authentication, localization, and CSV workflows.
Blazor Server MudBlazor EF Core SQLite Docker guided labs
Learning guide

speedy-bird-lynx
Flappy Bird-inspired arcade game exploring ReactLynx native UI: Android host, Lynx web preview, and a separate playable Canvas demo. iOS host source is a scaffold.
ReactLynx TypeScript Android Canvas Astro
Play · Docs

jonathanperis.github.io
Static portfolio and print-friendly resume, with build-time GitHub project data and a terminal-inspired UI.
Astro React TypeScript Tailwind CSS GitHub Pages
Visit · Resume

`$ cat /proc/tech_stack`

+-------------------+----------------------------------------------------+
| Core              | C#, .NET, ASP.NET Core, Azure, SQL Server          |
| Architecture      | CQRS, DDD, Microservices, Clean Architecture       |
| Exploring         | Rust, Go, Python                                   |
| Backend           | .NET 10, FastEndpoints, REST/gRPC, EF Core, Dapper |
| Compilers         | C#, Roslyn, LLVM                                   |
| Games & physics   | C11, raylib, Emscripten, WebAssembly, Bend 2, TOML |
| Web & UI          | Astro, React, ReactLynx, TypeScript, Tailwind CSS  |
| .NET UI           | Blazor Server, MudBlazor                           |
| Data & delivery   | PostgreSQL, SQLite, Docker, GitHub Actions, Bun    |
| Observability     | OpenTelemetry                                      |
| Practice          | Learning labs, contract tests, reproducible runs   |
+-------------------+----------------------------------------------------+

`$ neofetch`

   jonathan@itanhaem
   -----------------
   OS:        macOS / Linux / Docker
   Shell:     zsh + dotfiles
   Editor:    VS Code + JetBrains
   Uptime:    12+ years; .NET since May 2013
   Role:      Software Engineer, Derivative Path
   Loop:      build, inspect, measure, explain
   Packages:  NuGet, Bun, Cargo, pip
   Theme:     Dark Terminal Aesthetic

   Contact:   [email protected]
   Portfolio: https://jonathanperis.dev/
   Twitter:   @jonathanperis

Live demo → | Documentation →

_{hint: visit jonathanperis.dev and try the Konami code}

GeezerVison

Jonathan Peris jonathanperis

Achievements

Achievements

Highlights

`$ whoami`

`$ cat focus.md`

`$ ls ~/projects/active`

`$ cat /proc/tech_stack`

`$ neofetch`

Pinned Loading

Uh oh!