Work

Two products, and the practice behind them.

Everything here was designed, built, and is operated by PF International LLC. Nothing is white-labeled and nothing is outsourced.

Product
in release

Pyreva

Breathwork for explorers.

Breath, taken with an open mind, can take you somewhere else entirely. People have known this for a very long time. Pyreva exists for the ones who want to find out for themselves.

What is inside

  • Guided sessions. Choose a guide, press start, follow the breath.
  • Custom sessions. Build your own rounds, breath pace, and hold lengths.
  • Long holds and retention timers for deeper practice.
  • Soundscapes designed for the session, or play your own music.

How it was built

Two native codebases, SwiftUI on iOS and Jetpack Compose on Android, sharing a single design system and session engine specification. The breathing animation, audio ducking, and hold timing are written per platform so the pacing stays exact when the screen is off and the phone is in a pocket.

Privacy

No account. Nothing leaves your phone. There is no sign-up, no ads, and no in-app purchases. Session history is stored on the device using the platform's own local storage, and works offline.

Pyreva session screen showing a glowing nested-triangle medallion with the caption 'The breath is a door.' Pyreva hold screen with an open-ended retention timer. Pyreva box breathing session with a spiral geometry glyph. Pyreva privacy screen: 'No account. Nothing leaves your phone.'

Pyreva on Android and iOS

Platforms
iOS and Android
Status
Submitted to Google Play, July 2026. iOS release to follow
Category
Health & Fitness
Built with
SwiftUI, Jetpack Compose, Room, DataStore
Data collected
None. No account, no ads, no in-app purchases
Website
pyreva.com

Product
Web & mobile

Envoz

Your personal language assistant.

Nobody dreams of completing lessons. You dream of the conversation you avoid today, the interview, not going silent when someone speaks to you. Envoz is built for the gap between understanding a language and being able to speak it.

The problem it addresses

People finish an entire lesson tree and then discover they cannot hold a basic conversation. Recognizing words is one skill. Producing them live, under the pressure of a real exchange, is a different one, and almost nothing in the category makes you practice it.

What it does

  • Spoken practice with a tutor that remembers you between sessions.
  • Pronunciation feedback on the sounds you specifically struggle with.
  • Practice that builds toward conversations with real people, not scores.
  • Free to start, no card required.

Status

The web application is live at app.envoz.io. Native mobile applications are in testing ahead of release. The product teaches Spanish and English in both directions, and the interface and marketing site ship in both languages.

How it was built

A portable teaching engine kept deliberately independent of any host or interface, so the same pedagogy runs behind the web app and the native clients. The marketing and sign-up front end is a static site on Cloudflare's edge with serverless functions handling sign-up and attribution.

Envoz home screen with a card reading 'Pick up where you left off: Lesson 4'. The Envoz tutor answering a question about the Spanish word 'tanto' with an example sentence. An Envoz audio lesson: 'Let's practice for a bit. Listen and answer out loud.' The Envoz People screen, browsing other learners by the languages they speak and are learning.

Envoz on iOS

Platforms
Web, with native iOS and Android in testing
Category
Education
Languages
Teaches Spanish and English, both directions · interface in both
Built with
Astro, Cloudflare Pages and Functions, Python services
Website
envoz.io · app.envoz.io

Consulting
2017 — present

Client work

Alongside our own products, the company takes on a small number of client engagements each year. Client work is covered by confidentiality agreements, so we describe the kind of work rather than naming the businesses.

  • Building consumer and internal applications from specification through store or production release.
  • Taking over stalled or inherited codebases: assessing what is there, deciding what is salvageable, and getting releases moving again.
  • Integration work against third-party APIs, payment systems, and legacy internal services.
  • Infrastructure and deployment: moving applications onto edge and serverless platforms, and building the release tooling around them.
  • Architecture review and technical advisory for founders and small teams.

If you have something in one of these shapes, write to dev@pfinternational.xyz.

PF Systems — secure development

Security-focused engineering runs as its own practice under the PF Systems name, the trade name the company has used since before the products existed. It covers the work that needs to be handled separately from ordinary feature development: secure design and code review, hardening, and building systems where the security requirements come first rather than last.

That practice has its own site at pfsystems.io. Both it and the products are operated by the same legal entity, PF International LLC.