# Stephan Lensky

> Senior Software Engineer 2, Infra @ HubSpot

Location: Greater Boston, United States
Profile: https://flows.cv/stephanlensky

Full stack software engineer currently working on Developer Experience at HubSpot to create scalable AI coding infrastructure to accelerate and empower engineers. Previously, I worked on the Edge team, developing highly resilient load balancing infrastructure capable of handling millions of requests per second.

In my free time, I enjoy using programming to solve problems I see in the world around me, riding motorcycles, and playing the piano!

## Work Experience
### Senior Software Engineer 2 - Developer Experience AI @ HubSpot
Jan 2025 – Present | Boston, Massachusetts, United States
- Led development on internal AI background agent execution platform, allowing engineers to trigger background coding agents from GitHub and at scale using internal code migration tools. AI agents perform automatic code reviews (thousands/week), automatic code implementation (hundreds of PRs/week), and are deeply integrated with HubSpot developer tooling. Feature-set comparable with managed Microsoft GitHub Copilot coding agent at a fraction of the cost. Used Java, Docker, and Kubernetes.
- Deployed AI coding agents (Claude, Cursor, Copilot) for all HubSpot engineers, raising AI adoption to 100%. Developed internal MCP server, tools, and rules to give agents the context required to effectively work on HubSpot code. Used Python and FastMCP.

### Senior Software Engineer 1 - Infrastructure @ HubSpot
Jan 2023 – Jan 2025 | Boston, Massachusetts, United States
- Managed critical load balancing infrastructure which processes millions of requests/second, developing scaling automation, monitoring tools, and triaging production issues to ensure the reliability of the HubSpot product. Used Kubernetes, Envoy, Nginx, Cloudflare Workers, and Grafana/Prometheus/PromQL for observability.
- Migrated thousands of Kubernetes resources representing critical networking infrastructure to infrastructure as code (IaC), allowing for peer review of changes and reducing the time to expand to new AWS regions from months to just a few days. Used Kubernetes, Python, and Jsonnet.

### Senior Full Stack Engineer - Product @ Electives
Jan 2023 – Jan 2023 | Boston, Massachusetts, United States
- Created developer CLI to automate AWS Lambda deployments, reducing iteration time by >90% from a 30+ minute manual process to just a few minutes. Used TypeScript and Ink.
- Implemented redesigned course catalog page, developing frontend and backend components to meet designer specifications. Used TypeScript, React, DynamoDB, and AWS Lambda.

### Software Engineer II - Developer Experience @ Wayfair
Jan 2022 – Jan 2023 | Boston, Massachusetts, United States
- Implemented auto-merging dependency updates across Wayfair, resulting in 10,000+ auto-merged pull requests and saving hundreds of engineer hours. Used Python, Renovate, and GitHub.
- Led API redesign for internal development platform (IDP) backend, enabling Wayfair leaders to model problem domains, service ownership, and report costs for decoupled microservices. Led optimization efforts, allowing team to meet uptime SLAs and reducing endpoint latency by >95%. Used Python, FastAPI, Backstage, SQL Server, Buildkite, Docker, and Kubernetes.
- Mentored team in Python best-practices and scalability, establishing and leading weekly design meetings. Encouraged test-driven development, increasing test coverage in our services to >90%.

### Platform Engineer @ Chewy
Jan 2021 – Jan 2021 | Boston, Massachusetts, United States
- Implemented caching for search endpoint of configuration service deployed across Chewy for more than 10x speed-up. Used Python, AWS Lambda, DynamoDB, ALB, Elasticache, and Terraform.
- Created and ran load tests for configuration service. Used Scala and Gatling/Frontline.
- Automated RDS Aurora PostgreSQL database deployments. Used Golang, Jenkins, and Docker.

### Platform and Backend Engineering Internships @ Chewy
Jan 2019 – Jan 2021
Internships during all semester breaks since 2019. Used Python, Java, Docker, Spring Boot, JavaScript, Vue.js, and CircleCI.

- Back-End Engineer (2021) – Designed RESTful APIs supporting microservice migration.
- Platform Engineer (2020) – Created a developer CLI to facilitate AWS Okta SSO logins.
- Front-End Engineer (2020) – Supported migration to component-based front-end architecture.
- Release Engineer (2019) – Automated database deployments, saving DBAs 40+ hours/week.

### Software Intern @ Northwoods Software Corporation
Jan 2017 – Jan 2018 | Greater Boston Area
Used TypeScript and JavaScript to implement highly performant layouts for data visualization on the web. This included developing a novel heuristic algorithm for 2D rectangle packing, implementing a variation of the circle packing algorithm described by Wang et. al in "Visualization of large hierarchical data by circle packing," and implementing a quadtree data structure to improve algorithm performance.


## Education
### Bachelor of Science - BS in Computer Science
University of Massachusetts Amherst


## Contact & Social
- LinkedIn: https://linkedin.com/in/slensky
- Portfolio: https://slensky.com

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Source: https://flows.cv/stephanlensky
JSON Resume: https://flows.cv/stephanlensky/resume.json
Last updated: 2026-03-28