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 Calendly’s AI Scheduling team is building AI-native solutions on top of our best-in-class scheduling product, creating new ways for customers to automate scheduling, reduce coordination work, and get more value from Calendly. We’re looking for a Senior Fullstack Engineer who is equally comfortable building polished React and TypeScript experiences and designing the backend APIs, services, data flows, and integrations that power them. You’ll report to the Engineering Manager on the AI Scheduling team and own meaningful customer outcomes. This is a high-ownership role in a fast-moving, 0-to-1 product environment. You’ll turn ambiguous problems into pragmatic solutions, lead projects independently from discovery through launch, and help grow the product’s user base by improving activation, reliability, and trust; fixing customer-facing issues; and adding valuable new capabilities. You’ll partner closely with our ML engineers, who own much of the model and agent behavior, and flex into prompts, evaluations, guardrails, or AI-service work as needed. A day in the life of a Senior Fullstack Engineer at Calendly On a typical day, you will be working on: • Collaborating within your team to build new features that are targeted at our highest impact enterprise customers • Contributing to platform scaling initiatives • Meeting regularly with Product and Design to fine tune requirements • Attending agile ceremonies to help your team plan out their work and get it done • Working across squads to improve Engineering practices at Calendly • Reviewing implementation plans and pull requests from your peers • Mentoring and coaching other team members What do we need from you? We’re looking for a balanced fullstack engineer with strong product judgment, a bias toward action, and the ownership to move important work forward without step-by-step direction. You’ll spend most of your time coding and architecting systems while helping the team make sound decisions and execute reliably. • 7+ years of software engineering experience at a SaaS or technology company, with a track record of delivering high-quality customer-facing products. • Proven success in a 0-to-1 product environment, where requirements evolve, iteration is fast, and engineers help shape both the problem and the solution. • Significant experience with modern frontend development, including: • Building complex, production-grade user interfaces with React and TypeScript or similar technologies. • Working with state management, routing, forms, asynchronous data fetching, component libraries, and design systems. • Strong hands-on backend experience, including: • Designing and implementing REST or GraphQL APIs in Node.js, Ruby on Rails, or a similar web framework. • Working with relational databases such as PostgreSQL and understanding how schema and query design affect performance and reliability. • Building and operating service-oriented or microservice architectures across system and team boundaries. • Demonstrated ability to lead complex projects independently from discovery through launch and iteration, including coordinating cross-team dependencies and driving decisions to closure. • Experience building customer-facing AI or LLM-powered products is preferred, especially products that combine probabilistic AI behavior with reliable application workflows. • Availability for participation in an on-call rotation, ensuring prompt and effective responses to business-critical alerts outside of regular working hours. • Authorized to work lawfully in the United States of America as Calendly does not engage in immigration sponsorship at this time Tier 1 Salary Hiring Range $224,400—$271,920 USD Tier 2 Salary Hiring Range $205,700—$249,260 USD Tier 3 Salary Hiring Range $187,000—$226,600 USD The ranges listed above are the expected annual base salary for this role, subject to change. Calendly takes a number of factors into consideration when determining an employee’s starting salary, including relevant experience, relevant skills sets, interview performance, location/metropolitan area, and internal pay equity. Base salary is just one component of Calendly’s total rewards package. All full-time (30 hours/week) employees are also eligible for equity awards, and competitive benefits. Eligible Sales employees also qualify for a Sales Incentive program. Calendly uses the zip code of an employee’s remote work location, or the onsite building location if hybrid, to determine which metropolitan pay range we use. Current geographic zones are as follows: • Tier 1: San Francisco, CA, San Jose, CA, New York City, NY • Tier 2: Chicago, IL, Austin, TX, Denver, CO, Boston, MA, Washington D.C., Philadelphia, PA, Portland, OR, Seattle, WA, Miami, FL, and all other cities in CA. • Tier 3: All other locations not in Tier 1 or Tier 2 If you are an individual with a disability and would like to request a reasonable accommodation as part of the application or recruiting process, please let your Recruiter know when first connecting with them. Calendly is registered as an employer in many, but not all, states. If you are located in Alaska, Delaware, Hawaii, Idaho, Iowa, Montana, Nebraska, North Dakota, Rhode Island, South Dakota, and West Virginia, you will not be eligible for employment. Note that all individual roles will specify location eligibility. All candidates can find our Candidate Privacy Statement here Candidates residing in California may visit our Notice at Collection for California Candidates here: Notice at Collection This role may require occasional travel for company events, team collaboration, or offsites.