Daniel Lew

Software Engineer

Daniel Lew is a software engineer at Mastra based in Waterloo. A University of Waterloo graduate with a background in psychology, he previously worked at Netlify and Gatsby.

3 blog posts

Posts by Daniel Lew

Announcing Agent Editor

Edit agent instructions, tools, and display conditions from Studio with draft/publish versioning, or programmatically through the editor API.

Apr 8, 2026

Building low-latency guardrails to secure your agents

How we built a suite of out-of-the-box input processors and optimized them from 5000ms to under 500ms per request.

Jul 30, 2025

Reducing tool calling error rates from 15% to 3% for OpenAI, Anthropic, and Google Gemini models

We recently built a tool compatibility layer that reduced tool calling error rates from 15% to 3% for 12 OpenAI, Anthropic, and Google Gemini models, across a set of 30 property types and constraints.

May 29, 2025