Looking for my next opportunity·Putting in the work every day.

Hello, my name is

Otis Han

Software Engineer

Backend · Distributed Systems · Data & AI

M.S. Computer Science student at Seattle University, specializing in Data Science. Experienced in engineering event-driven microservices, CDC pipelines, and scalable AI applications.

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01 — About

About Me

I'm a Software Engineer and M.S. Computer Science student at Seattle University, specializing in Data Science.

My interests span backend engineering, distributed systems, data engineering, machine learning, and AI.

I enjoy building reliable systems that combine strong software engineering fundamentals with data-driven solutions.

Education

Seattle University

M.S. Computer Science — Data Science

GPA: 3.925 / 4.0 · 2025 — 2027

University of Science — VNUHCM

B.S. Computer Science — Software Engineering

GPA: 3.5 / 4.0 · 2020 — 2024

Technical Skills

Languages

Python · Go · C/C++ · Java · JavaScript · C# · TypeScript

Backend

Microservices · REST APIs · FastAPI · gRPC · Kafka · RabbitMQ · Docker · Protocol Buffers

Databases

PostgreSQL · MySQL · MongoDB · DynamoDB · Elasticsearch · Qdrant · Weaviate

Cloud

AWS · Azure · S3 · EC2 · EKS · Lambda · RDS · Spark · MapReduce

Tools

Jenkins · Argo CD · Debezium · Git · GitHub Actions · Linux

Scikit-Learn · PyTorch · TensorFlow · Optuna

02 — Experience

Experience

Nov 2023 — Jul 2025

Software Engineer

Hasaki Technology

• Engineered a distributed Order Management System in Go, processing 200K+ weekly orders using Kafka and background workers.
• Built real-time CDC pipelines connecting MySQL, Kafka, and Elasticsearch, eliminating manual Kafka publishing across 90% of synchronization workflows.
• Redesigned a legacy synchronous export engine into an event-driven Go/Kafka/MinIO pipeline processing 1M+ rows per export and reducing API response time to under 100ms.
• Built Go/Redis/Asynq workers for courier failover, address/COD synchronization, and refund processing, saving 10 hours/week of manual exception handling.
• Eliminated race conditions and duplicate transactions using Redis distributed locking and optimistic concurrency control.

03 — Coding

Coding Activity

Consistent practice across algorithms, distributed architecture, and open-source contributions.

LeetCode

@phuhanld ↗

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264✓ Solved

Easy

113/968

Med.

138/2122

Hard

13/979

Badges Earned

2 Badges

100 Days Badge 2026

Max Streak

61 Days

127 Active Days

912 submissions in the past one year

Total active days: 127Max streak: 61

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GitHub

@htnphu ↗Most Active Period: 2024

View 2024 Activity on GitHub ↗

2024 Contributions

1,886

Peak engineering activity

Public Repositories

Open source & systems

Peak Month

May (545)

1,409 in May–Jul

Key Deliverable

CareerCompass AI

Full-stack RAG & Kafka

1,886 contributions in 2024

Jan 1, 2024 — Dec 31, 2024 (Most Active Year)

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04 — Projects

Featured Projects

Selected engineering work covering distributed streaming systems, RAG pipelines, vector search, and predictive machine learning.

Featured Capstone Project · Ranked #1 (Grade 9.8 / 10)95% Retrieval Precision

CareerCompass AI

AI-Powered Recruitment & Semantic Job-Seeking Platform

View Case Study →GitHub ↗

Led a 6-member engineering team to build and ship an end-to-end AI recruitment platform. Engineered a real-time CDC pipeline using PostgreSQL, Debezium, and Kafka to stream data changes directly into Qdrant, Weaviate, and Elasticsearch. Built hybrid semantic search and LLM query expansion achieving 95% retrieval precision, alongside an automated recruiter matching engine.

FastAPIPostgreSQLApache KafkaDebezium (CDC)QdrantWeaviateElasticsearchOpenAI APIMinIODocker

Retail Sales Forecasting

M5 Dataset

55M+ Row Time-Series Machine Learning Pipeline

Processed and analyzed the 55M+ row Walmart M5 forecasting dataset. Engineered rolling statistical features, lag windows, and calendar event signals. Trained and hyperparameter-tuned XGBoost, LightGBM, and Random Forest models using Optuna and SHAP interpretability.

PythonPandasXGBoostLightGBMRandom ForestOptunaSHAP

View on GitHub →

05 — Contact

Let's connect.

I'm always interested in connecting with engineers, recruiters, and people building interesting systems.

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