CVE-2026-54694 Critical, CVSS 9.6
Stored XSS in NationalSecurityAgency/skills-service via User Registration Enabling Admin Account Takeover
Senior full-stack engineer
Reliable systems. Real-world scale.
I build dependable products across fintech, AI, and distributed infrastructure.
Yujia Lin
Engineer, builder, security researcher
Engineering judgment, from prototype to production.
Senior full-stack software engineer with 8+ years of experience in financial services, fintech, and enterprise software, plus hands-on AI/ML/NLP engineering in production. I've fine-tuned LLMs, built IVR infrastructure handling hundreds of thousands of migrated accounts, and architected systems tracking 6.5M+ monthly customer interactions. I thrive in high-ownership environments where engineering decisions directly drive business outcomes.
I have worked as a founder, individual contributor, and technical lead. That range helps me connect product decisions to reliable implementation.
Credentials
- AWS Certified Solutions Architect - Associate
- Senior Member, IEEE
- Member, Cloud Native Computing Foundation (CNCF)
- years building production software
- 8+
- monthly interactions monitored
- 6.5M+
- projected annual savings delivered
- $200K+
Security research
CVE-2026-35582 High, CVSS 8.8
OS Command Injection via unvalidated IN_FILE_ENDING / OUT_FILE_ENDING in Executrix
Experience
Spectrum Security
Jul 2026 - Present
San Francisco, CA (Hybrid)
Senior Software Engineer
Building security products for modern engineering teams.
Capital One
Apr 2023 - May 2026
McLean, VA
Senior Software Engineer
Java / Spring Boot / Python / PyTorch / LangChain / React / TypeScript / AWS / Kafka / PostgreSQL / OpenShift
- Led a team of 5 engineers to fine-tune Mistral-7B on IVR call transcripts using PyTorch and AWS SageMaker; integrated it into a LangChain chatbot surfacing real-time summaries for 10K+ agents and eliminating caller repetition.
- Led IVR routing for the Capital One BackBook migration, directing 500K+ migrated Discover accounts with zero service disruption.
- Designed and built a full-stack IVR monitoring system tracking 6.5M+ monthly calls with real-time alerting and anomaly detection.
- Delivered a self-service IVR integration projected to save $200K+ annually in OPEX by automating fraud and dispute workflows.
- Modernized IVR architecture from legacy VXML to Omilia Cloud Platform, improving routing efficiency by 20%.
- Expanded Omilia IVR to support Spanish NLU, driving a 4% increase in self-service utilization.
Pathway Labs
Feb 2023 - Apr 2023
San Francisco, CA
Full-Stack Software Engineer
TypeScript / Next.js / React / Node.js / MongoDB
- Enhanced the Student Information System admissions dashboard, reducing page load times by 10% and improving admin workflows for high-volume student record processing.
BunBao.com
May 2019 - Dec 2022
Fremont, CA
Full-Stack Software Engineer
JavaScript / Node.js / GraphQL / React / React Native / MongoDB / AWS
- Architected a custom ERP system from scratch managing purchasing, HR, and inventory for a multi-location food business, replacing all manual spreadsheet workflows.
- Scaled the engineering team from 1 to 4 developers; established Git branching, code review standards, and CI/CD pipelines.
- Led development of a React Native mobile tool that digitized kitchen and delivery operations, increasing task throughput by 70%.
- Integrated Square payment APIs, improving transaction throughput by 50%.
- Improved user onboarding UX, reducing sign-up steps by 80% and significantly increasing conversion rates.
WiFrost
Apr 2021 - Jul 2021
San Francisco, CA
Full-Stack Software Engineer (Part-Time)
JavaScript / Node.js / MongoDB / Go / Terraform
- Developed an IoT-focused speed test service to monitor network performance.
- Automated cloud resource provisioning for Magma Core deployments with Terraform, reducing setup time by 50%.
Menupedia
Sept 2018 - May 2019
San Francisco Bay Area, CA
Co-founder & Full-Stack Software Engineer
Node.js / Angular / TypeScript / MongoDB / Square / Python
- Built and launched a digital ordering SaaS platform, reducing restaurant table turnover time by 20%.
- Operated a local delivery service using the platform in Tucson.
- Graduated from Y Combinator Startup School, Class of 2018.
Tools change. Fundamentals travel.
Broad enough to own a product end to end, deep where reliability and scale demand it.
Languages
TypeScript / JavaScript / Java / Python / Go / C
AI / ML
PyTorch / Hugging Face / LangChain / LLM Fine-Tuning / NLP / NLU / AWS SageMaker / OpenAI Realtime API / Conversational AI
Frontend
React / Next.js / React Native / Angular / Vue.js / Tailwind CSS / Framer Motion
Backend
Node.js / Spring Boot / Express.js / Fastify / GraphQL / REST APIs
Data & Messaging
PostgreSQL / MongoDB / Apache Kafka / AWS S3 / ETL Pipelines / WebSocket
Cloud & DevOps
AWS / GCP / Kubernetes / Docker / GitHub Actions / OpenShift / Terraform / Datadog
Selected systems and products
LaborLens
Web platform for searching and analyzing U.S. Department of Labor records, including prevailing wage determinations and PERM labor certifications. Stream-processes large DOL Excel disclosures into MongoDB with real-time import progress and JWT-based role access control.
- Filters PWD & PERM data by company, title, case number, location, and year
- Real-time bulk import from DOL disclosure datasets
- Deployed via GitOps pipeline on k3s + ArgoCD
React / Node.js / Express / MongoDB / Docker / Kubernetes
2024
Omilia IVR Dashboard
Production monitoring platform for IVR call infrastructure at Discover Financial Services. Surfaces real-time API error rates, call-flow drop-off points, and anomaly alerts with immediate visibility into service degradation.
- 6.5M+ monthly interactions tracked
- Faster incident detection & root-cause analysis
- Improved SLA adherence across contact center
Spring Boot / React / PostgreSQL / AWS / Kafka
2020
BunBao ERP System
Custom ERP platform built from scratch to support a multi-location food business. Became the operational backbone covering purchasing, HR, inventory, vendor payment reconciliation, and cost center reporting.
- 20K+ customers served
- 2K+ daily delivery boxes processed
- 100+ employees managed
Express.js / GraphQL / MongoDB / React / AWS
2018
Menupedia Digital Ordering Platform
Digital ordering and delivery SaaS for restaurants. As co-founder, designed the product, built the full stack, onboarded clients, and ran a live delivery service on top of the platform.
- 20% reduction in table turnover time
- Eliminated paper-based workflows
- Y Combinator Startup School 2018
Node.js / Angular / MongoDB / Square / Python