Selected work

Hemut / Agents and backend systems

Hemut-MCP

A logistics copilot that finds the tools a question needs and coordinates answers across them.

System overview

  1. Question

    Find every part

  2. Tool retrieval

    Select relevant tools

  3. Execution

    Organization-scoped

  4. Answer

    Grounded in results

Architecture overview / simplified for the case study. Stage widths do not encode timings.

More than one answer

I built the agent layer for questions that needed several answers from different tools. The existing guardrails got in the way of complex, multi-part queries. Retrieving tools for the whole message could miss a secondary part of the question, so the work centered on covering each part and coordinating the calls needed to answer it.

Tools and tenant scope

Embedding-based retrieval selected relevant tools from the wider catalog. My backend work also moved database access onto organization-scoped sessions enforced by PostgreSQL row-level security, then addressed the query plans behind a slow handler.

What the baseline says

The reviewed baseline has 75 passing prompts out of 229, or 32.8%. My resume reports an end-to-end accuracy improvement from 33% to 99%. That is a separate reported result, not a demonstrated follow-up evaluation of those same 229 prompts.

What the evidence says.

reported

Agent end-to-end accuracy

33%to99%

Original resume outcome for the MCP agent layer and embedding-based tool retrieval. The reviewed baseline is recorded separately; no paired after-evaluation artifact is supplied for the 99% figure.

Source
Original resume: Hemut copilot accuracy
measured

Reviewed prompt baseline

32.8%

75 passing prompts divided by 229 reviewed prompts, rounded to one decimal place. This supports the baseline only, not a subsequent accuracy result.

Source
Internal prompt evaluation: reviewed June 16 run
Sample
75 passing / 229 reviewed prompts
Recorded
2026-06-16
reported

MCP tool catalog

192 tools

Tool catalog size reported in the original resume, with embedding-based retrieval selecting relevant tools. This is an implementation-scale figure, not an accuracy measurement or a current registry audit.

Source
Original resume: Hemut MCP tool catalog
reported

Worst database handler

10.2 sto487 ms

Original resume reports organization-scoped, row-level-security-enforced sessions across a nine-organization Postgres estate, followed by query-plan fixes. The reported handler timings have no specified percentile or load.

Source
Original resume: Hemut database hardening

Agent and backend engineering by DongYeop Lee at Hemut.

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