Job Description

As a Senior Strategist, you will design and orchestrate high‑impact performance systems that connect media, creative, audience strategy, and MarTech. You will ensure testing frameworks are sound, signals are reliable, and insights drive clear optimization decisions.

This hands‑on role requires strong platform fluency and analytical rigour. You will evaluate creative and audience performance across the funnel, partner cross‑functionally, and build the frameworks that turn campaigns into dynamic, learning systems—shaping how future strategies are developed and activated.

You will:

• Analyze performance across audiences, creative components (hooks, bodies, CTAs), and funnel stages to inform optimization, scaling, and creative refresh decisions
• Own the Learning Agenda - developing hypothesis‑led test‑and‑learn frameworks, maintaining the Hypothesis Log, and translating results into structured learning summaries and recommendations
• Partner closely with Media across Meta, Google, TikTok, Display, and CTV to evaluate activation strategy, audience segmentation, suppression logic, and signal performance
• Lead modular creative testing by translating brand messaging into funnel‑specific deployment logic, organizing component‑level performance, and briefing creative leads for scalable testing
• Develop integrated precision strategies across paid media, CRM, and digital experiences, supported by Signal‑to‑Response Maps across social, video, display, and emerging platforms
• Collaborate with Marketing Science, Ecosystem, and Activation teams to validate measurement approaches, ensure closed‑loop reporting, and maintain signal health, identity resolution, and taxonomy governance
• Lead weekly cross‑functional feedback loops between media, creative, and marketing science, while building strong relationships with core clients and discipline leaders

You have:

• 3-4 years of related experience in digital media, integrated strategy, performance marketing, media strategy, advertising analytics, or related disciplines
• Experience with qualitative research, including web analytics and metric analysis, and information architecture
• Understanding of paid media platforms, algorithms, activations and audience targeting
• Understanding of audience segmentation, suppression, and CRM integration
• Foundational knowledge of attribution models and performance KPIs
• Curiosity and comfort working in fast-moving, cross-functional environments
• Familiarity with DCO (Innovid, Celtra, platform-native tools) and creative testing frameworks
• Ability to connect performance metrics to creative or audience implications
• A commitment to learning

Nice to have:

• Experience across organic channels, including Organic Social and SEO
• Familiarity with CDPs, identity resolution systems and working with CRM or first-party data to support audience and signal strategy
• Experience developing testing frameworks or experimentation roadmaps
• Daily use of AI and/or LLM tools to accelerate insight development
• Experience with Innovid, Celtra, ArtBot, or similar platforms

What We Offer:

• Global maternity and parental leave
• Competitive benefits packages
• Vacation, compassionate leave, personal/sick days, and flex days
• Access to online services for families and new parents
• Early Dismissal Friday’s (off at 3:00 PM local time every Friday)
• 12 affinity groups
• Internal learning and development programs
• Enterprise-wide employee discounts

Our new hires & employees are the future of our organization, and we want to set you up for long-term success. In an effort to do so, we expect our team to work from an office a minimum of 3 days a week.

Critical Mass is an equal opportunity employer.

Critical Mass uses artificial intelligence in our recruitment process to enhance job postings, filter keywords during the review of prospective candidates, and, in some cases, transcribe interviews with our recruiters. Human review remains central to the process, and all hiring decisions are ultimately made by our team.

The Critical Mass Talent Acquisition team will only communicate from email addresses that use the URLs criticalmass.com, omc.comand us.greenhouse-mail.io We will not use apps such as Facebook Messenger, WhatsApp, or Google Hangouts for communicating with you. We will never ask you to send us money, technology, or anything else to work for our company. If you believe you are the victim of a scam, please review your local government consumer protections guidance and reach out to them directly.

If U.S. based: https://www.consumer.ftc.gov/articles/job-scams#avoid
If Canada based: https://www.canada.ca/en/services/finance/consumer-affairs.html
If U.K. based: https://www.gov.uk/consumer-protection-rights
If Costa Rica based: https://www.consumo.go.cr/educacion_consumidor/consejos_practicos.aspx