Open to staff & principal · 2026

Sai Harin
Purumandla.

// Engineer building intelligent systems — Rust, Python, and fine-tuned LLMs underneath.

Ten-plus years across Rust, Python, TypeScript and .NET. Currently shipping a multi-locale assistant at Apple, with RAG and small-model fine-tuning on the side. Turning research into products that stay up.

~/timelog
rustpythonjs
tl · ratatui
Based in
Jacksonville, FL
Status
Open to staff & principal
Focus
Rust · Python · LLMs
Experience
10+ years · full-stack
// stack — what I actually use
01 · Stack

No badges, no percentages. The things I reach for first, grouped lightly. If it's listed here I've shipped with it.

stack.

Languages
  • Rustcurrent focus
  • Pythoncurrent focus
  • C# / .NET Core
  • TypeScript
  • F#
AI / ML
  • PyTorch
  • LLM fine-tuning
  • LoRA / PEFT
  • llama.cpp / Ollamalocal
  • NLP / intent
Infra
  • Kubernetes
  • Docker
  • Redis
  • MongoDB / SQL
  • AWS / Azure
Frontend
  • React
  • Vue / Nuxt
  • Angular
  • Node.js
  • GraphQL / REST
// work — selected, not exhaustive
02 · Work

Five entries, oldest at the bottom. Each one is a thing I shipped or am shipping — not a job description.

work.

01Apple / Inspyr Solutions

Conversational AI platform at scale

Lead engineer (consultant) — Conversational AI

A context-aware automated assistant serving millions of users across multiple locales and surfaces. Low-latency, transactional, IVR + chat. Rust for node-to-node graph traversal at the core; Vue.js inspector on top; Node.js + MongoDB clusters around it. Fine-tuned LLMs for the harder intents — nuance over novelty.

RustVue.jsNode.jsMongoDBLLM fine-tuningNLP
2023 → present
02Rocket Mortgage

Internal loan management & analytics

Senior software engineer I

A short, dense engagement on an internal tool for managing loans across milestones with analytics on top. F# + C# microservices feeding a React frontend; Snowflake as the warehouse. Tight scope, fast delivery.

C#F#ReactSnowflakeMicroservices
2023
03Home Point Financial

Re-platforming a loan origination system

Lead software engineer

Broke a legacy Encompass-SDK LOS into micro-frontends and microservices on Kubernetes. GraphQL gateway, Redis for low-latency caching, and an ML-based region pricing model. Angular + React in front of .NET Core. I owned the scaling story.

.NET CoreAngularReactGraphQLKubernetesRedis
2020 → 2023
04Home Point Financial / AptaCore

Client-facing LOS — 99% of loan volume

Lead software engineer

Led the team that built and ran the customer-facing loan origination system. ReactJS + C# .NET Web API, transactional and fault-tolerant. Region-based pricing and appraisal. Served 2,500 associates and 250k+ customer logins.

ReactC#.NETWeb APIEncompass SDK
2017 → 2020
05National Informatics Center · India

Automatic Bill Reimbursement System

C# developer

Replaced a paper bill-reimbursement workflow with an ASP.NET + WPF system. Wrote a JavaScript SHA-1 path that beat the C# one, designed a ClickOnce WPF doc-scan flow, and migrated the data from PostgreSQL to SQL Server. Security tested with Burp Suite.

ASP.NETC#WPFWeb APISQL Server
2013 → 2015
// projects — personal builds, shipped
03 · Projects

Things I've built over the years — production systems, AI tooling, and full-stack platforms. Most started as a personal itch and grew into something real.

projects.

MandiMind

Python
Mandi Price Arbitrage Agent for Farmers
Python 3.11LangChainLangGraphFastAPI+8 more

Telugu Transliterator

Python
Romanized Telugu (Tenglish) → Telugu Script
Python 3.11ByT5HuggingFace TransformersPyTorch+7 more

TeluguBridge

Python
Local MCP Server for Telugu NLP
PythonMCP stdioIT3-llamaNLLB-200-1.3B+6 more

SnippetVault

JavaScript
Self-Hosted Team Code Snippet Manager with AI Copilot
JavaScriptNode.jsReact 18Vite 5+13 more

RiceDiseaseNet

Python
15-Class Paddy Disease Classifier — DINOv2 Fine-Tune
Python 3.11PyTorchDINOv2timm+6 more

Dev Desk

Python
AI Developer Knowledge & Ops Copilot
Python 3.12FastAPINext.js 14ChromaDB+9 more

TextLens

Python
Text Classification from TF-IDF to LLMs — Seven-Year Journey
Python 3.12scikit-learnNLTKBERT+6 more

ALRF

Python
Adaptive LLM Routing Framework
Python 3.12OpenAIAnthropicGoogle Gemini+8 more

DevPulse Buddy

C#
Windows Developer Context Overlay
C#.NET 6WPFSQLite+6 more
// daily-driver CLIs — small tools, in daily use
mcphost

MCPHost

Feb 2025 – May 2026

A Rust MCP server that exposes local developer tools to Claude Desktop — file operations, shell execution, git history, and code search. Rust binary starts instantly, uses minimal memory, and gives full control over allowed paths and commands.

chat

ChatCLI

Oct 2024 – May 2026

A Rust CLI for chatting with LLMs from the terminal. Starts with Ollama for single-turn queries, grows to support TOML prompt templates, SQLite conversation history, named sessions, OpenAI and Anthropic providers, streaming output, and a full ratatui TUI chat interface.

tl

TimeLog

Mar 2023 – Feb 2025

A local developer time tracker. tl start, do work, tl stop. Projects and tags for grouping. A ratatui TUI dashboard with a live ticking elapsed counter, project bar chart, and daily timeline view.

qn

QuickNote

Dec 2022 – Dec 2023

A fast, terminal-native Markdown notes manager. File-based storage — notes are plain .md files, metadata in a TOML index. No database. qn create 'my idea' opens in $EDITOR and tracks everything automatically.

// education — short list
04 · Education

Two degrees, plus a stubborn habit of reading documentation cover to cover.

education.

012015 → 2016

Master of Science · Cyber Security

Wright State University (WSU)

College of Engineering and Computer Science · Dayton, OH

Network security, applied cryptography, secure systems.

2015 → 2016
022011 → 2015

Bachelor of Technology · Computer Science & Engineering

Jawaharlal Nehru Technological University, Hyderabad (JNTUH)

Hyderabad, India

Algorithms, OS, distributed systems. First job started before the gown was off.

2011 → 2015
// about — short version
05 · About

The longer story, kept short. Three paragraphs and a sidebar.

about.

I've spent ten-plus years writing software for a living — mostly full-stack, mostly under pressure. The work I'm proudest of is rarely the most novel; it's the stuff that stayed up and stayed correct.

Today I'm at Apple on a conversational AI platform — multi-locale, transactional, low-latency. Rust handles the core traversal; Vue.js drives the operator surface; Node.js and MongoDB clusters sit underneath. Before this, a long run at Home Point Financial on the loan-origination platform.

On personal time I fine-tune small language models on intent data, build terminal-native tools in Rustbecause the shell should feel instant, and read the layers under the application — networking, security, hardware. There's a cyber-security MS in there too, and a stubborn opinion that application engineers should know more about what's under them.

Full nameSai Harin Kumar Reddy Purumandla
LocationJacksonville, FL
Time zoneUTC−05:00 (ET)
EducationMS · Cyber Security · WSU
UndergradB.Tech · CSE · JNTUH
Stack of choiceRust · Python · TS
Editornvim · zed (lately)
Currently readingnanoVLM walkthrough
Listeningmostly ambient / dub techno
// contact — say hello