As an AI Engineer at Wanted Lab in Seoul, I've focused on improving our core search capabilities and developing new agent-based services. I replaced our BM25 position search engine with a hybrid system combining SPLADE, dense, and lexical search. Through A/B testing, this change reduced the post-search bounce rate from 35% to 28% and increased search-driven application conversion from 6.7% to 8.4%.
I also built the career mentor multi-agent service. This service uses resume diagnosis to help users improve their resume levels. Additionally, I migrated our legacy position agent code to LangChain and LangGraph, streamlining our agent infrastructure.
At Waker Korea, I focused on developing AI agents and LLM-driven systems. One key project was a multi-agent AI chat API. It used LLM orchestration, grouped MCP tools for each agent, and a GuardRail module to block sensitive identifiers. I also built a financial stock analysis agent with Plan-and-Act workflows and a Llama-Index QA agent for validating extracted SEC filing data.
My work also included a Kafka-based news pipeline, integrating translation and summarization APIs. Earlier, I worked on SEC filing extraction using LLM and multimodal models. I also explored model compression techniques like distillation, pruning, quantization, and ONNX for translation models.
During my time as an NLP Developer at D&I Fabis in Seoul, I focused on building practical applications for patent documents. One key project was developing a BM25 patent document search engine, which I set up on a self-hosted Elasticsearch instance.
I also worked on improving semantic search. I domain-tuned Sentence-BERT for matching problem and solution sentences, which boosted accuracy by 1.2% compared to using vanilla BERT. Additionally, I created an API for keyword extraction and clustering in patent documents, using an LDA-based approach.
During my internship at Naver in 2021, I focused on improving training methods for ColBERT in information retrieval. This involved exploring how to generate hard negative samples using Learning-to-Augment.
My work aimed to refine the Triplet Loss training approach. It was a valuable experience to contribute to research in this area within a company like Naver, known for its search and AI advancements in Seoul.