I build full-stack apps, realtime voice tools, and booking systems for service businesses. My work covers the interface, backend, deployment, and the behavior users see when something goes wrong.
Open to software engineering roles
Seattle area · Open to relocation
B.S. Computer Science, University of Maryland · US citizen
Client delivery, realtime interaction, and data systems.
An English and Chinese website that turns a homeowner’s inspection request into a scheduling workflow for a Bay Area roofing contractor.
I built the bilingual interface and Calendar integration, with validation and visible recovery when a time is taken.
A voice interview workspace where the interviewer can follow both a candidate’s spoken reasoning and the code in their editor.
I connected WebRTC voice and debounced editor updates, then added temporary credentials and explicit session cleanup.
A U.S. fuel-price map and comparison toolkit that connects dated price snapshots to state details, trip estimates, and EV calculations.
I projected map geometry on the server and separated snapshot delivery, caching, and interactive comparisons.
Other products I build and maintain.
A document workbench that compares candidate evidence with job requirements and explains the gaps.
Project notesSpoken English practice with scenario prompts, turn-by-turn corrections, and optional Chinese-language hints.
Project notesA marketing website for local-business services, with consultation availability and booking through Cal.com.
Project notesA learning hub connecting programming guides, project building, and interview practice.
Project notesI’m To Yin Yu, a software developer in Lynnwood, Washington. I finished my computer science degree at the University of Maryland in December 2022 and have been building and shipping my own products since 2024.
I work across the frontend, backend, and deployment. The part after launch matters to me, too: tracing a failed request, making an error understandable, and deciding what a system should do when a dependency is unavailable.
The case studies here explain those decisions, including the limits of what I have tested. I’m looking for a software engineering role where I can contribute that experience and learn from a team.
