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

github.com/vic · denful.dev · berean.faith · vborja@apache.org

I build tools that empower other developers — at the intersection of functional programming, algebraic effects, and language/runtime implementation. I turn research-grade ideas into practical systems, and I ship them in the open.

Senior engineer, 25+ years, focused on compilers, effect systems, and reproducible developer tooling. Creator of the denful open-source Nix ecosystem — 25+ composable libraries, 1,300+ GitHub stars, with the flagship den framework running in production at the European Commission. Apache Software Foundation member. Currently building dnx, a rootless Nix evaluator on a new optimal-parallel reduction engine (Δ-Nets). I work full-time and fully in the open.

A single Rust binary that evaluates Nix without root and without a system-wide store, built on Δ-Nets (Salvadori, arXiv:2505.20314) — interaction nets with optimal parallel λ-reduction and perfect confluence (proven in the paper). Its standout property is being parallel by construction (confluence gives disjoint write sets, so independent reductions fire lock-free — verified across 1–8 threads); on top sits a designed semantic evaluation cache that will key on a computation's canonical normalized net rather than a recipe hash, a different layer from artifact caches that would hit across expressions that mean the same thing.

Honest status: the core reducer is built and tested (machine-checked n+2 β-step optimality on Church numerals; identical results across 1/2/4/8 threads); it evaluates a non-recursive pure-Nix subset today. General recursion is the active research frontier — root-caused, in progress, the same hard spot HVM/Bend hit. The semantic cache and build runner are designed. AGPL3, public infrastructure. → denful.dev/ecosystem/dnx

25+ focused, mostly zero-dependency Nix libraries that compose.

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

GoDNet / GoDNix — Δ-Interaction-Nets engine and a Nix→nets compiler in Go · ranix — a Nix parser in C (ragel + bison) · Apache Buildr PMC chair · asdf-vm maintainer · early Rubinius (Ruby VM) and Ragel contributor · jjui contributor.

2025 – present

• Founded and built a Spanish-language advanced scripture-study platform for scholars, pastors and your average grandma, on the principle that the Bible interprets itself through its own cross-references — "La Biblia, explicada por ella misma."

2023 – present

• Full-time, self-directed research and engineering on the denful Nix ecosystem and the dnx runtime.
• Grew denful to 1,300+ stars across 25+ libraries and European Commission production adoption of den.
• Designed and implemented the Δ-Nets reduction engine in Rust: machine-checked optimality (n+2 β-steps on Church numerals) and verified determinism across thread counts; root-caused the general-recursion frontier that gates the full runtime.

2018 – 2023

• Architected and shipped a mission-critical tax-calculation engine for automated flight refunds.
• Built a high-concurrency key-sharing system integrating legacy refunding platforms.
• Designed parser combinators that turned human-authored refund rules into executable logic, collapsing rule turnaround from days to hours.
• Established company-wide infrastructure (Nix, Terraform, Kubernetes) and Scala/Mill CI/CD pipelines.

2017

• Led a real-time route-monitoring system for an urban van-fleet platform.
• Built backend fleet-management services and a React operations frontend; contributed multiple libraries to the Elixir ecosystem.

2015 – 2017

• Shaped the architecture of a self-publishing platform for writers; built reader-engagement analytics and writer–reader features.

1999 – 2016

• Delivered solutions across Ruby on Rails, Node, Erlang, Elixir, and Neo4j (Karmashop, EasyBroker, and startup clients) and, earlier, enterprise Java with high-performance XML processing and build systems.
• Co-founded the Chilango Rails community meetup in Mexico City.

Languages — Rust · Go · Nix · Scala · Elixir · Ruby · Java · Elm · JavaScript/TypeScript/React · (Haskell & Erlang familiar) Paradigms & theory — functional programming · algebraic effects · interaction nets · actor model · type theory · dependent types (MLTT) · freer monads Specialties — compilers, parsers & VMs · optimal λ-reduction · content-addressed evaluation · build systems · reproducible/rootless tooling Infrastructure — Nix/NixOS · Kubernetes · Helm · Terraform · Docker · CI/CD

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

• Languages — Spanish (native) · English (fluent; ~50% hearing loss — I prefer async, written communication)
• Open to remote roles in compiler/language implementation, effect systems, Nix infrastructure, and developer tooling
• Interests — type theory · interaction nets · poetry · theology · the intersection of technology and art