Lee Zhen Yang, Sebastian

Lee Zhen Yang, Sebastian

Seattle, WA LinkedIn GitHub

Engineering manager who ships end-to-end: built a $167B corporate portfolio platform from scratch with a team of 4 (no PM), shipped an AI assistant to production in 8 weeks, and previously scaled a startup from employee #15 to $1B GMV across 7 countries in Southeast Asia. Looking to lead a larger team building consumer-scale products in APAC.

Work Experience

Amazon, Software Development Manager, Seattle, Jun 2024 – Present

Leading engineering for Amazon’s $167B investment portfolio platform — owning product strategy, architecture, and delivery across 11 business units (Finance, Legal, Tax, Treasury) with no PM/TPM support.

  1. Built and shipped AI chat assistant (Investment Management Assistant) end-to-end in 8 weeks — LLM tool-use orchestration, React frontend, evaluation framework (96% accuracy on 111 test cases), reducing portfolio query time from minutes to 3 seconds for 200+ users
  2. Reduced API p99 latency 86% (5,200ms to 728ms); restored $714M+ in portfolio accuracy through systematic database investigation and targeted remediation
  3. Delivered reporting platform and cross-org integrations (Finance, FinTech, Accounting, Tax), eliminating manual quarterly reporting and saving 175 hours/quarter through automated reconciliation
  4. Launched platform consolidating 530+ holdings with 6x user growth in Year 1; authored 5-year vision and half-year roadmap with capacity modeling and phased delivery
  5. Managed hiring, onboarding, and coaching — including formal performance plans, career redirection conversations, and mentoring a new engineer to first production deployment within 2 weeks

AWS, Senior Startup Solutions Architect, Singapore, Jun 2022 – Jun 2024

Led a team of 5 Solutions Architects. Technical lead for containers, databases, and AI/ML across ASEAN startups.

  1. Mentored 7 Solutions Architects and 2 specialist candidates; 3 promoted to higher-level roles within 18 months
  2. Drove measurable customer outcomes: genomics startup (41% revenue growth), data analytics unicorn (20% below planned cloud cost), SME compliance platform (25% cost reduction) — through architecture guidance and optimization
  3. Delivered 19 gamified learning events to 496 companies across Asia-Pacific (CSAT 4.62/5); built 4 reusable modules adopted org-wide; scaled delivery team 8x
  4. Orchestrated 18 database workshops for 772 companies across 4 countries (CSAT 4.71/5) with translated content
  5. Built “RoboChef” food waste reduction solution showcased at AWS re:Invent 2023 Builder’s Fair; led IoT hardware demo at 7 APAC events

AWS, Startup Solutions Architect, Singapore, Sept 2020 – May 2022

Managed portfolio of 150+ startups including 3 unicorns. Influenced $2M+ ARR.

  1. Drove 30% average cost reduction for startup clients through strategic resource allocation and cloud best practices
  2. Designed and executed 42+ technical workshops across 5 ASEAN markets and 4 customer segments (4.2/5 CSAT)
  3. Retained multi-cloud customer evaluating competitor by delivering architecture PoC that reduced query time from hours to under 1 minute — CTO committed to AWS-first strategy
  4. Authored 6 reusable technical assets (blogs, code samples, videos, e-books) reaching 4,000+ users

Amazon, Software Engineer II (Alexa), Sunnyvale, May 2018 – Sept 2020

Alexa Shopping Notifications — millions of daily notifications across hundreds of millions of devices.

  1. Built comprehensive testing framework unblocking 12 production releases after a 4-month deployment freeze
  2. Resolved critical issue affecting 5% of notification traffic by coordinating across 4 domain teams
  3. Designed CLI tool for Natural Language Understanding (NLU) developers improving work efficiency by 50%

ShopBack, Software Engineer, Singapore, July 2015 – May 2018

Employee #15. Scaled 3→7 countries, 5M+ users, $1B GMV. Raised $40M by Series C.

  1. Built core cashback and merchant integration features serving 2,000+ partners processing 2.5M+ monthly transactions
  2. Led frontend architecture for white-label platform, enabling B2B partnerships that expanded revenue channels
  3. Implemented e2e and unit testing — 80% reduction in reported bugs, supporting 250% YoY order volume growth
  4. Optimized web performance (5+ second improvement), directly impacting conversion rates across 7 markets

Earlier Roles

  • Afteryou (May 2014 – July 2015): Built mobile app saving housing agents 8 hours/week
  • CSIT (July 2013 – May 2014): Designed web service architecture improving interoperability and security
  • Rocketfuel Inc (Jan 2011 – Dec 2011, internship): Built revenue forecasting feature with 95% reliability

Education

National University of Singapore

  • Master of Computing (Information Systems) — Dec 2013 – Dec 2015
  • Bachelor of Computing (Information Systems, Minor in Technopreneurship), 2nd Upper Honours — Aug 2009 – July 2013

Stanford University — NUS Overseas Colleges (Exchange Program), Jan 2011 – Dec 2011

Technical Publications & Projects

AWS Workshops (GA)

  1. Database for Developers — delivered to 772+ companies across APAC
  2. EKS Workshop for Startups — reused 54 times in 6 months

AWS Technical Content

  1. ECS Autoscaling with Custom Metrics — blog + code sample
  2. Monitoring Memory Usage in Amazon Lightsail — blog
  3. A Startup Guide to AWS — e-book

Technical Skills

Languages & Frameworks: Python, JavaScript/TypeScript, Java, SQL React, Flask, SQLAlchemy, Express

AI/ML: LLM orchestration (tool-use, Bedrock Converse API), prompt engineering, evaluation frameworks, MCP

Infrastructure: AWS (Lambda, CDK, RDS, Glue, Step Functions, Bedrock, CloudWatch), PostgreSQL, DynamoDB, Docker, CI/CD