Senior Full Stack Engineer, App Platform

What’s in it for you? 

Ready to make a serious impact? Millions of people already rely on Calendly, and we’re still in the midst of exciting product growth — it’s a fantastic time to join us. Everything you’ll work on here will accelerate your career to the next level. If you want to learn, grow, and do the best work of your life alongside the best people you’ve ever worked with, then we hope you’ll consider allowing Calendly to be a part of your professional journey.

About the team & opportunity

Our Mission

We empower product engineering teams to build consistent, high-quality features efficiently through shared tooling, standards, and infrastructure that accelerate development while maintaining coherence across our platform.

How you will contribute

As a Senior Engineer on Calendly’s App Platform team, you will be instrumental in building the foundational capabilities that power our product ecosystem. Your work will directly impact how our engineering teams ship features and how millions of users experience Calendly.

You will focus on critical platform services including:

• Analytics and Experimentation to enable data-driven decision making across product teams
• Feature Flagging infrastructure to provide controlled and predictable releases at scale
• Real-time UX Infrastructure to enable server-to-client data delivery to support dynamic and responsive experiences
• Future Platform Services as our platform continues to grow and evolve

Why this role matters

We’re at an inflection point. As Calendly continues to scale, our product teams need increasingly sophisticated platform capabilities to move quickly without sacrificing quality. In this role you will help define how we approach distributed platform services, contribute to engineering standards, and build resilient infrastructure that our growing platform demands. Your technical expertise and collaboration will shape not only what we build, but how we build across our engineering organization.

A day in the life of a Senior Full Stack Engineer at Calendly

Building Platform Infrastructure
Design, develop, and maintain the services and frameworks that product teams depend on. You will work hands-on with technologies like Ruby / Rails and Go to build highly resilient, scalable systems; from real-time server-to-client data infrastructure to analytics and experimentation services.

Technical Leadership and Collaboration
Contribute to architectural decision and technical strategy for platform services. Provide guidance to engineers across the organization, share your expertise in distributed systems, and help establish patterns and practices that raise the bar for engineering excellence.

Contribute To Critical Initiatives
Own and contribute to significant projects from concept to production. Whether it’s building and launching real-time server-to-client infrastructure, optimizing service performance, or designing new platform capabilities, you will deliver high impact solutions with quality and reliability at the forefront.

Cross-Functional Partnership
Partner with product managers, designers, and engineering teams across Calendly to understand their needs and translate them into robust platform solutions that serve the entire organization.

Operational Excellence
Ensure reliability and performance of platform services through thoughtful monitoring, testing, and incident response. Participate in on-call rotation to support business-critical systems and drive continuous improvement based on operational learnings.

What do we need from you?

• 7+ years of software engineering experience at a SaaS or technology company with a strong focus on backend and distributed systems
• Deep experience in service-oriented architecture, microservice patterns, and building highly resilient / scalable systems
• Proven experience building and operating high traffic, high availability platforms in production environments
• Strong proficiency in building internal tools, frameworks, and SDKs that other engineers use
• Experience with API design and real-time data systems (Server Side Events, Websockets, etc)
• Excellent problem solving skills with the ability to diagnose complex system issues and implement effective solutions
• Strong communication skills, you can explain complex technical concepts clearly to both technical and non-technical stakeholders
• Authorized to work lawfully in the United States of America as Calendly does not engage in immigration sponsorship at this time

Bonus

• Exp