Software Engineer · Open Source Author · Effect Systems, Compilers & Runtimes

github.com/vic · denful.dev · x.com/oeiuwq · vborja@apache.org

I build tools that empower other developers. My work lives at the intersection of functional programming, algebraic effects, and language/runtime implementation — turning research-grade ideas into practical systems people use every day.

Senior software engineer with 25+ years of experience in developer tooling, effect systems, compilers, and functional programming. Creator of the denful open-source Nix ecosystem — 25+ composable libraries with 1,200+ GitHub stars — and author of dnx, a rootless, single-binary Nix runtime built on interaction-net optimal reduction. Apache Software Foundation member and long-time maintainer across the Ruby, Elixir, and Nix ecosystems. I design small, composable, mathematically grounded systems and ship them in the open.

• Language & runtime implementation — compilers, parsers, virtual machines, interaction nets (Δ-Nets), optimal λ-reduction, content-addressed evaluation
• Algebraic effect systems — designed and shipped effect/handler libraries in Rust, Go, and Nix
• Functional programming — Scala, Haskell, Elm, Elixir; type theory, dependent types (MLTT), freer monads
• Nix & reproducible tooling — aspect-oriented configuration, build systems, rootless content-addressed stores
• Open-source leadership — community building, maintainership, technical writing, and documentation

Languages: Rust, Go, Nix, Scala, Elixir, Ruby, Java, Elm; Haskell & Erlang (familiar); JavaScript/TypeScript/React Paradigms: Functional programming, algebraic effects, interaction nets, actor model, type theory Infrastructure: Nix/NixOS, Terraform, Kubernetes, Helm, Docker, CI/CD, cloud architecture Tools & frameworks: ZIO, Akka, Kyo, Mill, Maven, Buildr, parser combinators (fastparse) Specialties: Developer tooling, compilers & VMs, build systems, effect systems, reproducible builds

A single Rust binary that delivers reproducible packages and builds without root and without a system-wide store, on a runtime built from Δ-Nets — an interaction-net model performing optimal λ-reduction with perfect confluence. One mathematically grounded engine that builds packages, evaluates multiple surface languages, caches work by its computed meaning (not by filename), and machine-checks proofs — on the bet that package managers, language runtimes, and proof assistants are secretly the same problem. Recently achieved native evaluation of general recursion, a long-standing open problem for this class of engine. AGPL3, developed in the open as public infrastructure. → denful.dev/ecosystem/dnx

A family of 25+ focused, composable, mostly zero-dependency Nix libraries — collectively 1,200+ stars:

• den (420+ ⭐) — context-aware, aspect-oriented configuration framework: declarative pipelines, host/user schemas, batteries included
• import-tree (270+ ⭐) — recursive Nix module loader; the ecosystem's most widely adopted library
• flake-file (120+ ⭐) — generate flake.nix from typed module options
• dendrix (120+ ⭐) — community-driven Dendritic Nix distribution
• flake-aspects (60+ ⭐) — zero-dependency aspect composition with dependency DAGs and parametric providers
• zen — ~100-line, MLTT-verified module system, ~26× faster than lib.evalModules
• nest — declarative multi-node NixOS fleets with a CSS mental model
• plus ned, dnzl, bend, nix-versions, checkmate, with-inputs, fastest, dag, and more

• nfx — algebraic effects with handlers for Nix from four kernel primitives
• fx-rs — ability-style algebraic effects for stable Rust (after Scala's Kyo)
• fx.go — algebraic effect-handler system for Go with typed capabilities
• rust-effects / nix-effects — freer-monad effects with an MLTT dependent type checker

• GoDNet / GoDNix — a Delta Interaction Nets engine and a Nix→nets compiler in Go
• ranix — a Nix language parser in C (ragel + bison)

• Apache Software Foundation — member; PMC / project chair for Buildr
• asdf-vm — maintainer and plugin author for the extensible version manager
• Rubinius — early contributor to the Ruby VM (implemented Enumerable in Ruby)
• Ragel — Ruby and Rubinius bytecode backends for the state-machine compiler
• darcs, Fancy, vtd-xml, jjui — contributor

2018 – 2023

• Architected and implemented a mission-critical tax-calculation engine for automated flight refunds
• Built a high-concurrency key-sharing system integrating legacy refunding platforms
• Implemented parser combinators turning human-authored refund rules into executable logic
• Established company-wide infrastructure with Terraform, Nix, and Kubernetes; built Scala/Mill CI/CD pipelines
• Contributed to core business architecture during the early startup growth phase

2017

• Led a real-time route-monitoring system for an urban van-fleet platform
• Designed and implemented backend tracking and fleet-management services
• Built a React operations and customer-facing frontend
• Contributed multiple libraries to the Elixir ecosystem

2015 – 2017

• Shaped the architecture and design of a self-publishing platform for writers
• Built reader-engagement analytics and social features for writer–reader communication

2016

• Delivered solutions across Node, Erlang, Elixir, and Neo4j for multiple startup clients

2013 – 2015

• Ruby on Rails applications for crowdfunding non-profits (Karmashop) and real-estate management (EasyBroker)
• Co-founded the Chilango Rails community meetup

1999 – 2012

• Delivered enterprise Java solutions for multiple clients
• Specialized in high-performance XML processing and build systems

Computer Science & Electrical Engineering — ITESM, Mexico (2003)

• Languages: Spanish (native), English (fluent; ~50% hearing disability — I prefer async, written communication)
• Founder and organizer of developer community meetups; frequent open-source mentor
• Interests: type theory, effect systems, interaction nets, poetry, theology, and the intersection of technology and art
• Open to remote opportunities in developer tools, compilers, effect systems, and Nix infrastructure