Internal Operations Manager

Overview 12100 Collective is a growth marketing agency based in NYC founded by alumni of Meta's growth team, servicing clients with over $100M annual revenues across a variety of industries. We pride ourselves on being world class at our craft and pairing data-driven strategies with excellent creative to unlock results. We are looking for a detail-oriented, proactive Operations Manager to own the internal infrastructure of our agency. This role is responsible for keeping our people, systems, and finances running smoothly behind the scenes. You'll oversee our external accounting firm, manage HR and contractor operations, and serve as the internal go-to for anything that keeps the agency running. This role reports directly to the CEO. Key Responsibilities HR & People Operations - Own the full employee and contractor lifecycle — onboarding, offboarding, and everything in between - Manage payroll, benefits, and open enrollment in coordination with Rippling - Oversee recruiting logistics: posting roles, sourcing candidates, coordinating interviews - Handle employee moves, tax documentation updates, and year-end 1099/W-2 coordination Finance Oversight - Serve as the internal point of contact for our external accounting firm, ensuring all finance tasks are completed accurately and on time - Oversee client and contractor invoicing workflows, AR follow-up, and cash flow visibility - Maintain access to all client contracts and confirm billing details - Flag financial issues and escalate to the CEO as needed Contractor & Vendor Management - Act as the primary internal contact for contractors on general business questions - Oversee contractor onboarding and offboarding across all platforms - Manage contracts, SOWs, BAAs, and rate renewals Client & Account Operations - Own the operational side of client onboarding and offboarding - Coordinate internal kickoffs, platform setup, and billing configuration for new accounts - Ensure clean handoffs when accounts close IT & Security - PM internal security processes in coordination with our IT team - Maintain platform access lists and ensure offboarding is executed cleanly - Keep security SOPs up to date Systems & Admin - Own internal tools and subscriptions: renewals, access, cost tracking - Maintain SOPs across all operational functions - Manage Toggl administration and time tracking oversight Minimum Requirements - 2-3 years of experience in operations, office management, or a similar role — agency experience a plus - Strong attention to detail and ability to manage multiple workstreams simultaneously - Comfortable working independently and owning processes end to end - Experience with HR platforms (Rippling or similar), accounting tools (QuickBooks, Mercury, Bill.com), and project management tools (Notion, Linear) - Excellent written and verbal communication skills - Availability and responsiveness are a must — this role requires consistent weekly engagement Bonus Skills - Background in a startup or agency environment - Comfort with AI-assisted workflows and tools Location Fully remote or join us in our Brooklyn office. 10–20 hours per week with the opportunity to grow into a full-time role.