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.

Dev Desk

Python
AI Developer Knowledge & Ops Copilot

A RAG system that ingests a developer team's documents, logs, tickets, and markdown notes into a hybrid vector + keyword index, then answers natural-language questions grounded in that real data. Streams answers token-by-token with clickable citations back to the exact chunk.

Python 3.12FastAPINext.js 14ChromaDB+9 more
2024 – 2025v1.0.0

TextLens

Python
Text Classification from TF-IDF to LLMs — Seven-Year Journey

A Python NLP project that classifies news articles by topic. Started with TF-IDF + logistic regression in 2019, moved to BERT fine-tuning in 2020, simplified with HuggingFace pipelines in 2022, added GPT-3.5 in 2023, survived the OpenAI SDK breaking change in 2024, and finally cut the cloud dependency entirely in 2026 by running Llama 3 locally.

Python 3.12scikit-learnNLTKBERT+6 more
2019 – 2026v2.0.0

MandiMind

Python
Mandi Price Arbitrage Agent for Farmers

A LangChain/LangGraph agent that pulls daily APMC mandi prices from the Government of India's Agmarknet API, reasons across price differentials, transport cost, and weather forecasts, and recommends optimal sell locations for farmers — delivering advice in Telugu. A WhatsApp bot lets farmers text their crop and quantity and receive a response in Telugu within 30 seconds.

Python 3.11LangChainLangGraphFastAPI+8 more
2025v1.0.0

ALRF

Python
Adaptive LLM Routing Framework

A lightweight Python framework that classifies incoming queries by complexity, routes them to the right LLM provider and model, optionally injects a RAG context hook, evaluates confidence, and retries via escalation — all without any LLM inside the framework itself. Supports OpenAI, Anthropic, Google Gemini, and local Ollama. Every routing decision is persisted to SQLite and surfaced in a Rich CLI dashboard.

Python 3.12OpenAIAnthropicGoogle Gemini+8 more
Oct 2025 – Apr 2026v0.1.0

TeluguBridge

Python
Local MCP Server for Telugu NLP

A local MCP server exposing four Telugu NLP tools — translate, transliterate, simplify, summarize — evolving from a Gemma3-backed prototype to a stack of specialized models. EN→TE uses IT3-llama, TE→EN uses NLLB-200-1.3B, Roman→Telugu uses IndicXlit. Integrates as a sidecar with MandiMind.

PythonMCP stdioIT3-llamaNLLB-200-1.3B+6 more
May 2025 – Apr 2026
// daily-driver CLIs — small tools, in daily use
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.

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.

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