Sirui Chen · Philadelphia, PA
Full-stack engineer who ships typed, production-grade systems.
From an OS kernel and a distributed search engine to dashboards people actually operate — I build with strict TypeScript, real CI gates, and deploys that are boring on purpose. M.S.E. in Computer and Information Science, University of Pennsylvania (May 2026); B.S. in Computer Science with a second major in Mathematical Science, Washington University in St. Louis.
Projects
Selected work
Two of these run live in your browser. The rest show range: product dashboards, distributed systems, OS internals, applied ML.
A complete project-management front end: full CRUD for plans, requirements and defects, reusable templates, a Gantt view and a dashboard of derived metrics, in about 1,900 lines of vanilla JavaScript with no build step, verified by an 80-plus-check Playwright suite. You can operate it live on this site.
Authenticated dashboards, maps, charts, filters, and CSV export over a PostgreSQL schema that joins LA crime data with California retail sales records. Graded 99/100.
End-to-end distributed search platform with a custom crawler, indexer, PageRank, replicated key-value store, multithreaded web server, and an RDD-style compute layer named Flame.
C implementation of Unix-like OS features: a shell with job control and I/O redirection, a SIGALRM-driven priority scheduler over spthread, full process lifecycle with signals and zombies, and the PennFAT on-disk filesystem — all wired up to a sandboxed live terminal on this site.
Approach
How I build
What I optimize for as an engineer, in four sentences.
- I prefer typed contracts end-to-end — data is converted into well-defined, validated structures at the edge and stays typed all the way through the system, instead of carrying raw blobs around.
- I treat warnings as defects and edge cases as part of the spec. Defensive defaults, deterministic resource cleanup, and explicit error paths beat clever code that breaks under hostile input.
- I ship small, reviewable units behind real CI gates. Lint, typecheck, and build must pass before anything reaches production, and deploys are boring on purpose.
- I like working across the stack and across roles — UI craft, backend systems, infra, and talking to non-engineers about what we are actually trying to do.
Skills
What I work with
Grouped by where they show up in my day-to-day.
Languages
Frontend
Backend & Data
Cloud & Systems
ML & NLP
Practices
Experience
Recent roles
Research Assistant — Prof. Chris Callison-Burch· University of Pennsylvania
May 2025 – Aug 2025
Built and evaluated retrieval-augmented generation workflows for DARPA SciFy and OpenScholar using score-based filtering, contrastive model work, and domain data preparation.
Python Developer Intern· CambioML
Dec 2023 – Mar 2024
Built an LLM-powered data portal with Danswer AI to search datasets from AWS, Datarade, and Snowflake across ingestion, indexing, and user-facing discovery workflows.
Lab Assistant — Vision-Assisted Self-Driving F1Tenth Car· Washington University in St. Louis
Aug 2023 – May 2024
Improved model robustness in glare and shadow conditions through targeted data augmentation, experiment tracking, and evaluation.
Research
Selected research
University of Pennsylvania · May 2025 – Aug 2025
Retrieval-Augmented Generation for DARPA SciFy and OpenScholar
Designed and evaluated retrieval-augmented generation workflows for scientific question answering on DARPA SciFy and OpenScholar, with a focus on retriever ranking quality and reproducible evaluation.
Washington University in St. Louis · Aug 2023 – May 2024
Vision-Assisted Self-Driving F1Tenth Car
Improved perception robustness for a 1/10-scale autonomous racing car under glare and shadow, and integrated new sensor input through ROS.
Contact
Hiring a full-stack engineer?
I finished my M.S.E. at Penn in May 2026 and I’m interviewing for full-time roles now — U.S. work authorization in hand, and happy to relocate. The fastest way to reach me is siruichen2023@outlook.com.