Juho Choi

Open to NA SWE roles

Juho Choi

I build the systems that make AI agents predictable in production.

Most engineering happens in the messy middle: retries that lose money, agents that drift off-script, migrations that touch real users. That's where I build.

5th-year CS + BBA at Waterloo, five engineering roles deep. I've shipped payment infrastructure at Clearco, an AI market-research agent at QuadReal, and data pipelines at Eclipse Automation. On my own time, I wrote a disk-based database engine in Go from scratch. The thread: systems where retries don't lose money and agents don't drift in production. Mostly, I like shipping things people use.

Experience

Where I've shipped.

  1. University of Waterloo, Mechanical Engineering LabResearch Assistant
    Apr 2026 – Present
    • Supporting full-stack IoT monitoring platforms with real-time data visualization for research operations.
  2. ClearcoSoftware Engineer
    Sep 2025 – Dec 2025
    • Built an automated GoCardless mandate regeneration pipeline in Node.js, decoupling mandate recovery from payment retries to eliminate race conditions across concurrent payment flows.
    • Engineered a targeted NSF ACH retry flow in TypeScript that preserved daily payment-processing windows and improved cash collection reliability.
    • Shipped Prisma and PostgreSQL migrations and backfills that restored 600+ legacy records, corrected 16,000+ exchange-rate fields, and resolved 40+ billing discrepancies.
  3. Escape PlatformsSoftware Engineer
    Apr 2025 – Jul 2025
    • Built Node.js APIs backed by DynamoDB and caching to reduce latency for interactive map workflows in a real-time application.
    • Set up GitHub Actions CI/CD for lint, test, and deploy on every PR, reducing release cycle time by over 80%.
    • Owned end-to-end map feature delivery at a 9-person startup using Flutter and Mapbox; shipped real-time location search serving 100 users.
  4. QuadReal Property GroupSoftware Engineer
    Jan 2025 – Apr 2025
    • Reduced market-analysis time by 60% by designing and owning an AI market research agent with a Go backend and a React/TypeScript chat interface.
    • Automated weekly analysis of 100+ market reports via Python, Tesseract OCR, and LlamaIndex, served through an internal AI platform.
    • Accelerated site-selection decisions for 200 analysts across 1M+ properties by building 6 pages and 4 interactive maps with React, MapLibre, and deck.gl.
  5. Eclipse AutomationData Engineer
    Jan 2024 – Apr 2024
    • Automated PostgreSQL-to-dbt ELT reporting, eliminating 80% of manual work across 10K+ rows for 20+ analysts.

Education

Where I've studied.

Skills

Tools I reach for.

Languages

GoTypeScriptPythonSQL

Backend

Node.jsNestJSFlaskDjangoPrismadbt

Frontend

ReactNext.jsFlutterTailwind CSS

Cloud

AWSGCPDockerGitHub ActionsDynamoDBn8n

Projects

Things I've built.

Disk-Based Database Engine

Disk-Based Database Engine

A disk-based DB engine in Go with B+Tree indexes for O(log N) reads, crash recovery via copy-on-write and fsync, and a SQL parser supporting multi-table queries.

GoB+TreeSQL
WAVE

WAVE

Full-stack daily journaling app with Google OAuth, localStorage draft auto-save, and chapter-level API caching; serves 40 active users.

Next.jsTypeScriptPostgreSQLDrizzle

Writing

Recent posts.

Engineering May 10, 2026 5 min read

Project bootstrap

Start a project with a deliberately minimal harness — interactive USER gates, docs-first, no autonomous loop — and graduate to autonomy only after customer evidence (personas, interviews, simulation reports) appears.

#ai-ml #agent-harness #patterns
Engineering May 4, 2026 5 min read

Thin hook manifest

Have the hook config file declare only *what events to subscribe to* and route every one of them to a single handler binary; keep all branching, transformation, and policy in that handler.

#ai-ml #agent-harness #patterns
Engineering May 3, 2026 4 min read

Human intervention log

A single append-only file where an autonomous harness records every task it could not automate, who handled it manually, and the condition under which automation could resume.

#ai-ml #agent-harness #patterns
All posts

Contact

Let's talk.

If you're hiring, building, or just thinking out loud about production systems, I want to hear from you.

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