James Chen

Led development of Notion AI summarization and brainstorming services using Java, Python, OpenAI APIs, caching layers, and asynchronous pipelines, supporting AI capabilities that contributed to Notion's growth to a $10B valuation and more than $41M in monthly revenue. Owned core sync and collaboration infrastructure for Notion's editor and database layer using Java and PostgreSQL, improving consistency and reducing failure rates by 40% under high-concurrency workloads across 20M+ active workspace pages. Directed frontend AI workflow integration using React and TypeScript, embedding contextual "Ask AI" experiences into collaborative editors used across more than 20M+ of workspace pages daily.

Senior Software Engineer at Notion (2022-04 – Present)

• Led development of Notion AI summarization and brainstorming services using Java, Python, OpenAI APIs, caching layers, and asynchronous pipelines, supporting AI capabilities that contributed to Notion's growth to a $10B valuation and more than $41M in monthly revenue.
• Owned core sync and collaboration infrastructure for Notion's editor and database layer using Java and PostgreSQL, improving consistency and reducing failure rates by 40% under high-concurrency workloads across 20M+ active workspace pages.
• Directed frontend AI workflow integration using React and TypeScript, embedding contextual "Ask AI" experiences into collaborative editors used across more than 20M+ of workspace pages daily.
• Built cloud-native inference and API infrastructure on AWS and GCP using Docker, Kubernetes, CI/CD pipelines, and feature-flag rollouts, enabling stable zero-downtime deployments across 12+ weekly production releases.
• Designed automated regression, contract, and concurrency testing frameworks using JUnit, Mockito, PyTest, and integration testing pipelines, preventing production sync failures and improving release reliability.
• Mentored 6 engineers through architecture reviews, incident debugging, and backend design discussions, improving engineering quality standards and accelerating onboarding across distributed product teams.

Software Engineer at Notion (2019-04 – 2022-04)

• Developed collaborative editing and database features using Java, PostgreSQL, and WebSockets, supporting platform growth from 1 million to 20+ million users while improving real-time synchronization reliability.
• Built and launched a public API platform with OAuth authentication, versioned REST endpoints, SDK integrations, and automated contract testing, enabling dozens of third-party integrations within the first quarter after launch.
• Optimized backend pagination and query execution logic using caching, indexing, and concurrency-safe validation, improving large-database retrieval performance by 20% without introducing production regressions.
• Diagnosed and resolved critical synchronization race conditions using enhanced instrumentation, deterministic queue ordering, and regression testing, eliminating lost-edit incidents across desktop and mobile collaboration flows.

Software Engineer at ClickUp (2017-06 – 2019-04)

• Built core task-management and collaboration functionality using Java, Node.js, React, PostgreSQL, and REST APIs, helping scale an early-stage productivity platform during rapid customer acquisition and feature expansion.
• Built collaborative frontend workflows using React, TypeScript, and real-time state synchronization, delivering task management and commenting experiences that supported 40% growth in mobile user adoption after launch.
• Developed early AI-assisted productivity workflows and unified search integrations using Python, NLP pipelines, third-party APIs, and asynchronous background processing for cross-workspace knowledge retrieval.
• Collaborated directly with product leadership, designers, and backend teams in a fast-moving startup environment, rapidly prototyping customer-facing workflows and shipping iterative releases under evolving business requirements.

Bachelor of Science (B.S.) in Computer Science – University of Illinois Urbana - Champaign (2012 – 2016)