Ivan Parfenchuk is a software developer who builds applications and developer tools. His work includes a DeepSeek Harness plugin for model-based verification, the Rately journaling app, and practical writing about building software with language models.[1][2][3][4]
Start with LLM-as-a-Verifier Plugin for DeepSeek Harness →
Education
University studies
2006 – 2011
[6]Links
Personal website
GitHub 
X LinkedIn Instagram Telegram Blog Senior Frontend Developer · Puzzel
Contributions
Separate generating a candidate from judging it
His LLM verifier plugin can launch several independent DeepSeek Harness agent attempts, score their outputs with a configured model, and return the strongest candidate. Other operations compare supplied candidates or assess progress along a trajectory. Repeated grades and separate criteria reduce reliance on one judgment, but the resulting score remains a model assessment without a reference solution.[2]
Turn personal workflows into small applications
Parfenchuk describes Rately as a daily journaling system organized around life themes and habits. In a later experiment, he used language-model prompts to build a browser-based PDF compressor with page editing, previews and file-size feedback. He describes solving his own workflow problem and iterating on the interface.[3][4]
Tools, writing & talks
Writing, research & talks
Start here
A plugin that generates or compares candidates, applies repeated model-based grading and exposes the results for inspection.
Read how grading and the verifier view work before following the setup instructions. You need a working DeepSeek Harness profile and an explicitly configured grading model; compare the grades with the actual candidate outputs.
Developer and maintainer[2][7]Original source- Building a PDF Size Reducer with One-Shot LLM Promptsblog.theivan.io
A short first-person walkthrough of turning a recurring PDF workflow problem into a browser application.
Author[4]