---
title: "Production AI for Matchmaking - Ditto"
description: "Member of Technical Staff (Software Engineer) at Ditto, May 2026 - Present. At Ditto, I build production systems for a consumer dating product: reliable message delivery, chatbot evaluation, and location-based matching."
url: https://hieumpham.dev/work/ditto
site: https://hieumpham.dev
---

# Production AI for Matchmaking - Ditto

- Company: Ditto
- Role: Member of Technical Staff (Software Engineer)
- Type: Member of Technical Staff (Software Engineer)
- Period: May 2026 - Present
- Location: San Francisco, CA
- Skills: TypeScript, Redis, BullMQ, Braintrust, LLM Evals, H3

Figures describe work during May 2026 - Present; these are self-reported career results, not live product statistics.

## AI Matchmaking Over iMessage

At Ditto, I build production systems for a consumer dating product: reliable message delivery, chatbot evaluation, and location-based matching.

## Reliable Multi-channel Delivery

Built and own SendIntent, the delivery layer for iMessage, SMS, and email. It preserves message ordering across 100+ phone lines and 3 providers during bursts of 400+ messages per minute, using Redis leases, epoch fencing, and durable per-line BullMQ queues.

## Chatbot Quality and Latency

Built a release-gating harness with 6 Braintrust scorers: 3 deterministic and 3 LLM judges. Identified the AI stage as 85–90% of response latency and shipped skill pre-activation and no-reasoning fast paths.

## Location-based Matching

Shipped the location picking and saving flow, H3 geo-indexed intersection matching, and an LLM venue-selection agent. The system was adopted across Summer 2026 matches to select real-world date spots.

---

Machine-readable index: https://hieumpham.dev/llms.txt | Sitemap: https://hieumpham.dev/sitemap.xml