Executive Assistant​/Office Manager San Francisco · Operations

Reactor is building real-time generative video infrastructure, and we're growing fast. This is a generalist operations role at a pivotal moment: we're a lean, high-output team and we need someone who can keep the founders moving, the office running, and the day-to-day from falling through the cracks.

You’ll work directly with our co-founders (CEO and CTO) and collaborate closely with our Founding Strategy & Operations Manager. This is a role for someone who takes ownership and figures things out.

• Executive support: Manage calendars, coordinate meetings, book travel, and handle logistics for our CEO and CTO so they stay focused on the highest-leverage work.
• Office management: Own the day-to-day of our SF office: ordering supplies, managing vendors, coordinating with building management, and making sure the space runs smoothly for the whole team.
• Recruiting coordination: Partner with the team to schedule interviews, manage candidate communications, and keep our hiring processes organized as we scale.
• Team support: Serve as a resource for the broader team on administrative and facilities needs, including coordinating travel for conferences and team events.
• Events & culture: Help plan and execute team events, offsites, and meetings that reinforce our culture as we grow.
• Special projects: Take on ad hoc projects across operations and vendor relationships as the company scales. We're a startup, so the scope of this role will grow with us.

• You have 1–3 years of experience in an EA, office management, operations coordinator, or similar role. Ideally at a startup or fast-moving tech company.
• You're proactive and self-directed. You don't wait to be told what needs doing: you notice it, own it, and follow through.
• You're highly organized with strong attention to detail, and you stay composed when priorities shift quickly.
• You have excellent written and verbal communication skills, since you'll be interacting with the founding team, external vendors, and occasionally external partners.
• You're flexible and adaptable. This JD is not an exhaustive list. At a fast-growing startup, the scope of this role will grow with the company, and you're energized by that.
• You're comfortable working onsite in San Francisco five days a week.

• Experience supporting executives at an early-stage startup (seed through Series B).
• Familiarity with tools like Google Workspace, Slack, and Notion.
• Experience with recruiting coordination or supporting a hiring process.
• Comfort with ambiguity: you've worked in environments where the process doesn't exist yet, and you helped build it.
• Competitive SF salary at an early-stage company backed by top investors
• Generous health, dental, and vision coverage
• The opportunity to grow and learn quickly