Campus transit, rebuilt as a kinetic control system.
SlugLoop turned live GPS hardware, Firestore, Express, React, and Google Maps into a student-built shuttle tracker for UCSC. This archive now frames the project like the system it was: operational, precise, and moving.
Fleet signal
Firestore-backed vehicle state
Campus loop
Stops, hills, routes, and Metro overlap
Build mode
Hardware, backend, map, and product
SlugLoop OS
campus transit control
Telemetry frame
Preserved map logic, abstracted into a command-view route.
Science Hill
Quarry Plaza
East Field
Cowell
ETA
02:14
Route
Loop
Metro
5 lines
Fleet signal
Realtime
Campus loop
UCSC
Build mode
Student-led
01
Top 10
global Google Solution Challenge finalist
02
Only US
team in the 2023 global finalist group
03
4 students
built the first working version at UCSC
04
500+
commits across the open-source project
System profile
A practical app with real operational depth.
The flow now follows the product story: pressure, signal, software, public proof. Each section has room to breathe while still feeling like one continuous route.
Problem
Transit pressureA campus where timing the loop bus mattered.
UCSC students were making daily tradeoffs around unpredictable loop shuttles, steep hills, full Metro buses, and late arrivals. SlugLoop started from that frustration and turned it into a visible system.
Hardware
Real devicesThe project reached below the web app.
The team reprogrammed existing GPS-emitting hardware and worked with campus base stations so shuttle positions could move from physical buses into a real-time software pipeline.
Software
Full stackA student-built data pipeline became a live map.
React rendered the map, Firestore carried real-time vehicle state, Express handled ingestion and Metro sync, and Google Maps gave riders a familiar view of campus movement.
Recognition
Public proofThe work traveled beyond campus.
SlugLoop was recognized by UCSC News, local press, Santa Cruz Works, Devpost, and the 2023 Google Solution Challenge as a student-built response to a real transportation problem.
Architecture
From bus ping to moving pixel.
The preserved map still mirrors the original system shape: physical hardware produced the signal, the backend normalized it, Firestore carried state, and React rendered campus movement.
01
GPS hardware
Reprogrammed bus hardware emitted location pings from the campus fleet.
02
Base stations
Campus receivers forwarded raw data toward the SlugLoop backend.
03
Express ingestion
A Node/Express server validated pings, normalized data, and wrote Firestore documents.
04
Firestore
Collections for buses, Metro vehicles, and bus stop ETAs became the app data layer.
05
React map
The client read Firestore and rendered route-filtered vehicles and stops on Google Maps.
Recognition
Public proof, not portfolio filler.
Coverage from campus and local outlets gave the project external weight, while Google's finalist stage proved the student system could travel beyond Santa Cruz.
Route log
The build story now reads like motion.
A compressed path through discovery, prototype, beta, finalist stage, and archive mode. The full timeline keeps the longer record intact.
January 2023
1. The frustration became visible
Student conversations around unreliable campus shuttle timing framed the problem SlugLoop would solve.
January 2023
2. CruzHacks formed the team
Bill Zhang, Alex Liu, Annie Liu, and Nicholas Szwed formed the project team and began turning the idea into a working app.
February 2023
3. Hackathon prototype
The team built the first version during CruzHacks and earned recognition for its use of GitHub.
March-May 2023
4. Public beta and competition run
SlugLoop was released as a public beta and submitted to the Google Developer Student Clubs Solution Challenge.
April 2023
5. Top 100 selection
The project advanced into the Top 100 projects in the Google Solution Challenge.
Crew
Four students carried the whole stack.
The team section is deliberately compact: enough personality to humanize the system without breaking the forward momentum of the page.
Retrospective
A map demo, a case study, and a signal that still holds.
SlugLoop is no longer positioned as a commuter utility. It now works as a polished archive of shipped work, public impact, and technical range.
Built for a real campus mobility problem, not a classroom prompt.
Integrated physical bus hardware, base stations, backend services, and a web client.
Shipped an open-source PWA with Google Maps and Firestore-backed real-time data.
Coordinated with campus staff and local transit context while staying student-led.
Earned public recognition from UCSC, local press, and Google Solution Challenge judges.