Ruby Labs

About this role

We are looking for a Senior User Acquisition Manager to drive and scale paid acquisition across Meta and other sources such as: Google ,TikTok etc.  for our subscription-based products.

This is a hands-on role with a strong focus on performance, experimentation, and scalable growth. You will be responsible for building, optimizing, and scaling acquisition systems, working closely with creative, product, and analytics teams.

The ideal candidate combines strong execution skills with strategic thinking, is highly data-driven, and thrives in a fast-paced environment where speed and ownership matter.

Responsibilities

Performance & Scaling

• Own and scale paid acquisition across Meta 
• Continuously improve key metrics (CPA, ROAS, ROMI , ROI)
• Identify and scale winning campaigns while maintaining efficiency

Campaign Management & Optimization

• Build and manage campaign structures aligned with scaling goals
• Continuously test and optimize creatives
• Run structured A/B tests with clear hypotheses and learning agendas

Data Analysis & Decision-Making

• Analyze performance across the full funnel
• Identify bottlenecks and growth opportunities
• Translate data into actionable insights and decisions

Creative Collaboration

• Partner closely with creative teams to develop high-performing ads
• Provide clear, data-driven feedback on hooks, angles, and formats
• Help define and scale repeatable creative frameworks

Growth Experiments

• Identify new scaling levers within existing channels
• Test new audiences, formats, and campaign types
• Contribute to testing new acquisition channels when relevant

Cross-functional Collaboration

• Work closely with product, analytics, and growth teams
• Align on KPIs, tracking, and reporting
• Ensure data accuracy and proper event tracking

Qualifications

Experience

• 3–5 years of experience in user acquisition / performance marketing
• Strong hands-on experience with Meta and other traffic sources
• Proven track record of managing and scaling $1M+ monthly budgets
• Experience with subscription-based products (web) is a strong plus

Analytical Skills

• Strong understanding of performance metrics (CPA, ROAS, retention)
• Ability to analyze data and make fast, informed decisions

Execution & Ownership

• Highly proactive and self-driven
• Comfortable owning performance outcomes end-to-end
• Strong ability to manage multiple campaigns and priorities simultaneously

Strategic Thinking

• Data-driven mindset with a structured approach to testing
• Ability to balance short-term performance with long-term scalability
• Focus on building repeatable acquisition systems

Communication & Collaboration

• Clear and structured communication
• Ability to present insights and performance to stakeholders
• Strong collaboration with creative and cross-functional teams

About us

Ruby Labs is a leading tech company that creates and operates innovative consumer products. We offer a diverse range of opportunities across the health, education, and entertainment industries. Our innovative teams are driving the future of consumer-led products, and we're always looking for passionate individuals to join us. Learn more about our story at: https://rubylabs.com/about-us/

About the role

We’re building and scaling a profitable D2C platform used by hundreds of thousands of customers globally, processing large volumes of traffic and revenue every month.

The product is well beyond MVP: it’s battle-tested in production, monetizing at scale, and now entering a phase of rapid growth and expansion. We’ve recently launched a second product in the same ecosystem and are doubling down on building a world-class engineering organization to support continued scale.

We’re looking for a Senior Next.js Full-Stack Engineer who can combine hands-on technical excellence with strong ownership. You’ll be responsible not just for shipping code, but for shaping architecture, improving reliability, raising engineering standards in a high-paced environment.

This role is not about maintaining a legacy system. It’s about scaling real products used by real users — fast.

If you’re looking for a comfortable 9–5 role, this won’t be the right fit. But if you’re excited by ownership, accountability, and building high-quality systems under real-world pressure, read on.

Key Responsibilities

• Take ownership of core product components from concept to deployment.
• Collaborate with the Product team to design scalable and maintainable architectures.
• Participate in (and lead) code reviews and ensure best practices across the team.
• Mentor junior and mid-level developers, providing guidance and fostering growth.
• Contribute to hiring and onboarding new team members.
• Maintain high code quality and application performance in a fast-paced, high-traffic environment.
• Set up and improve CI/CD pipelines and development workflows.
• Monitor, debug, and improve the stability and scalability of the system.
• Help shape the engineering culture as the team grows.

Qualifications

Core Technical Skills

• At least 4 years of experience with Next.js for full-stack application development.
• At least 2 years of experience with Next.js App Router
• Strong expertise in JavaScript/TypeScript and modern ReactJS.
• Experience leading a small team in a continuous deployment environment
• Experience with CI/CD pipelines, Docker, and cloud infrastructure (preferably AWS, Cloudflare).
• Solid understanding of PostgreSQL and Redis, including performance tuning and schema design.
• Experience with A/B testing frameworks and using analytics to drive product decisions.
• Familiarity with CMS (preferably Payload)

Leadership & Collaboration

• Demonstrated ability to mentor other engineers and elevate team performance.
• Clear communication style — able to explain complex topics clearly and concisely.
• A proactive mindset — you spot issues before they become problems and take ownership.
• Comfortable making technical decisions and defending them with logic and data.
• Experience leading teams or projects.

Nice to have

• Experience in D2C SaaS products.
• Exposure to performance marketing, customer funnel optimization, or rapid MVP cycles.
• Contributions to open-source or technical blogs.
• Experience working in a fast-paced, high-growth startup environment

Location

Ruby Labs operates within the CET (Central European Time) zone. Applicants from any country are welcome to apply for the position as long as they are located within approximately ± 4 hours of CET. This ensures optimal collaboration and communication during working hours.

Benefits

Discover the perks of being part of our vibrant team! We offer:

• Remote Work Environment: Embrace the freedom to work from anywhere, anytime, promoting a healthy work-life balance.
• Unlimited PTO: Enjoy unlimited paid time off to recharge and prioritize your well-being, without counting days.
• Paid National Holidays: Celebrate and relax on national holidays with paid time off to unwind and recharge.
• Company-provided MacBook: Experience seamless productivity with top-notch Apple MacBooks provided to all employees who need them.
• Flexible Independent Contractor Agreement: Unlock the benefits of flexibility, autonomy, and entrepreneurial opportunities. Benefit from tax advantages, networking opportunities, reduced employment obligations, and the freedom to work from anywhere. Read more about it here: https://docs.google.com/document/d/1tzxGX4Uu7Ts_HCLFXESKLnKaaBfVCPf1f9AYZPrkjJM/preview?tab=t.0

Be part of our fast-growing team and seize this excellent opportunity for personal and professional growth!

Interview Process

After submitting your application, we conduct a thorough review which typically takes 3 to 5 days, but may occasionally take longer due to the volume of applications received. If we see a potential fit, we proceed with the following steps:

• Recruiter Screening (40 minutes)
• Technical Interview (60 minutes)
• Final Interview (60 minutes)

Life at Ruby Labs

At Ruby Labs, we move fast, aim high, and expect the same from our team. We’re not here to play small—we’re here to build, grow, and win. That means we look for people who are ambitious, driven, and ready to give their best every single day.

This is a place for individuals who thrive under pressure, embrace challenges, and see opportunity in every obstacle. If you’re hungry to achieve, motivated by impact, and want to grow at the speed of your own ambition, Ruby Labs offers the platform to make it happen.

Here, effort is matched with reward. We recognize those who go all in and deliver results, and we create space for people who want more—more responsibility, more growth, and more success.

About the role

At RubyLabs, we’re seeking a senior AI Engineer (Node.js / Next.js / TypeScript) to shape our AI infrastructure and drive production-ready LLM experiences. You’ll work in a modern stack, making data-driven decisions around model performance, reliability, and cost.

You’ll own advanced prompt systems, structured outputs, and complex LLM workflows using LangChain or LlamaIndex. Observability, debugging, and evaluation are core to the role, leveraging Langfuse and AI gateways like OpenRouter to continuously improve model quality and operational efficiency. You’ll take full ownership of key AI features from experimentation to live production.

Key Responsibilities

• Advanced Prompt Engineering: Designing complex, dynamic prompt templates with conditional logic and efficiently reusing information and context within prompts to maximize generation quality and reasoning.
• Structured Outputs & Schemas: Implementing various response schemes (JSON mode, function calling, Zod/JSON schemas) to ensure AI outputs are predictable and ready for seamless integration into application logic.
• Prompt Engineering & Evaluations: Building robust evaluation pipelines and using Langfuse to collect feedback and score the quality of responses in real time.
• Tracing & Debugging: Performing deep debugging of complex LLM chains using Langfuse traces to identify bottlenecks and optimize for cost, latency, and context window usage.
• AI A/B Testing: Running systematic experiments across different models via OpenRouter (e.g., comparing Claude 3.5 Sonnet vs. GPT-4o) and analyzing results based on quantitative metrics.
• Data-Driven Decisions: Making deployment decisions for new prompts or models strictly based on quantitative benchmarks and trace data, rather than intuition.
• Output Scoring & Analysis: Developing scoring systems to analyze the “Problem → Solution” chain and identify root causes of hallucinations or logic errors using Langfuse analytics.
• Model Performance & Fine-Tuning: Regularly re-evaluating model performance as new architectures emerge and performing fine-tuning when necessary to meet specific domain requirements.

Qualifications

• Node.js & Next.js: Deep knowledge of the stack to build reliable services and handle complex LLM-generated data.
• Dynamic Prompting Skills: Proven experience in building prompts where content is highly dependent on input variables and context injection.
• OpenRouter Experience: Experience working with unified APIs, managing rate limits, and selecting the most cost-effective models for specific tasks.
• Langfuse (or similar): Understanding of LLM observability principles — setting up tracing, creating test datasets, and integrating scoring systems.
• Evaluation Methodology: Experience with frameworks like RAGAS or building custom “LLM-as-a-judge” systems.
• Analytical Mindset: Ability to transform raw generation logs into actionable business metrics and technical insights.
• Iterative Mindset: Focus on continuous product improvement through constant feedback loops.

Nice to have

• Fine-Tuning: Practical experience in fine-tuning models for specific domain tasks or JSON compliance.
• RAG Architecture: Understanding how to build and optimize Retrieval-Augmented Generation systems, including indexing, retrieval, and re-ranking.
• Python: Basic knowledge for working with data science scripts or AI evaluation libraries.

Location

Ruby Labs operates within the CET (Central European Time) zone. Applicants from any country are welcome to apply for the position as long as they are located within approximately ± 4 hours of CET. This ensures optimal collaboration and communication during working hours.

Benefits

Discover the perks of being part of our vibrant team! We offer:

• Remote Work Environment: Embrace the freedom to work from anywhere, anytime, promoting a healthy work-life balance.
• Unlimited PTO: Enjoy unlimited paid time off to recharge and prioritize your well-being, without counting days.
• Paid National Holidays: Celebrate and relax on national holidays with paid time off to unwind and recharge.
• Company-provided MacBook: Experience seamless productivity with top-notch Apple MacBooks provided to all employees who need them.
• Flexible Independent Contractor Agreement: Unlock the benefits of flexibility, autonomy, and entrepreneurial opportunities. Benefit from tax advantages, networking opportunities, reduced employment obligations, and the freedom to work from anywhere. Read more about it here: https://docs.google.com/document/d/1tzxGX4Uu7Ts_HCLFXESKLnKaaBfVCPf1f9AYZPrkjJM/preview?tab=t.0

Be part of our fast-growing team and seize this excellent opportunity for personal and professional growth!

Interview Process

After submitting your application, we conduct a thorough review which typically takes 3 to 5 days, but may occasionally take longer due to the volume of applications received. If we see a potential fit, we proceed with the following steps:

• Recruiter Screening (40 minutes)
• Technical Interview (60 minutes)
• Final Interview (30 minutes)

About us

Ruby Labs is a leading tech company that creates and operates innovative consumer products. We offer a diverse range of opportunities across the health, education, and entertainment industries. Our innovative teams are driving the future of consumer-led products, and we're always looking for passionate individuals to join us. Learn more about our story at: https://rubylabs.com/about-us/

About the role

We are looking for a Head of User Acquisition to take full ownership of execution quality, operational processes, and performance delivery within the User Acquisition Department.

This is a hands-on leadership role, you will manage a team of 3–6 User Acquisition Managers across different seniority levels and will be fully accountable for the team’s KPIs, execution discipline, ROI, and results.

You are expected to build strong operational processes, maintain high execution quality, and actively participate in performance management. This role requires deep hands-on expertise - not theoretical leadership.

This is a high-impact, high-responsibility role. Results, efficiency, and ROI are the primary measures of success.

Key Responsibilities

• Team Leadership & Development
  Lead, mentor, and develop a team of User Acquisition Managers. Ensure continuous growth in knowledge, execution quality, and performance across the team.
• Hands-On Performance Management
  Stay deeply involved in daily operations. Be able to step into ad accounts at any moment to diagnose issues, optimize performance, launch campaigns, and demonstrate best practices.
• Budget Ownership at Scale
  Manage and oversee $1M+ monthly advertising budgets across all networks, ensuring disciplined spend allocation, controlled scaling, and performance stability.
• Facebook as a Core Channel
  Be exceptionally strong in Facebook Ads or Google Ads, taking full responsibility for Facebook Ads as the primary acquisition channel.
• Analytics, Insights & Data-Driven Decisions
  Work deeply with performance data and analytics to identify insights, inefficiencies, and growth opportunities. Collaborate closely with the Analytics team to stay continuously informed about funnel performance, attribution, cohort behavior, and overall acquisition efficiency.
• Process & Reporting Setup
  Build, document, and enforce clear UA processes, reporting standards, and performance review cadences. Ensure transparency and full control over daily, weekly, and monthly results.
• Creative Ideation Process
  Build and manage a structured process for sourcing, testing, and iterating creative ideas. Work closely with Creative Managers to continuously identify and scale top-performing creatives.
• Operational Excellence
  Ensure disciplined execution across account structure, testing frameworks, scaling logic, and performance monitoring.
• KPI Ownership
  Take full responsibility for team KPIs, including efficiency and ROI metrics. Results and outcomes are the primary measure of success.

Qualifications

• Senior User Acquisition professional with leadership experience.
• Proven hands-on management of $1M+ monthly advertising budgets.
• Deep, practical expertise in Facebook Ads or Google Ads, with ownership of Facebook Ads as the primary acquisition channel.
• Proven experience managing multiple paid acquisition sources beyond Facebook and Google is a strong plus.
• Strong analytical mindset with the ability to work deeply with data to extract insights.
• Experience collaborating closely with Analytics teams to guide decision-making.
• Focused on high-ROI, efficient scaling, not just spend growth.
• Comfortable working directly inside ad accounts, not only at the reporting level.
• Experienced in training, coaching, and developing UA teams.
• Structured, disciplined, and highly accountable.
• Able to operate effectively in a fast-paced, high-pressure environment.

• Clear, direct communicator focused on results.

   

Location

Ruby Labs operates within the CET (Central European Time) zone. Applicants from any country are welcome to apply for the position as long as they are located within approximately ± 4 hours of CET. This ensures optimal collaboration and communication during working hours.

Benefits

Discover the perks of being part of our vibrant team! We offer:

• Remote Work Environment: Embrace the freedom to work from anywhere, anytime, promoting a healthy work-life balance.
• Unlimited PTO: Enjoy unlimited paid time off to recharge and prioritize your well-being, without counting days.
• Paid National Holidays: Celebrate and relax on national holidays with paid time off to unwind and recharge.
• Company-provided MacBook: Experience seamless productivity with top-notch Apple MacBooks provided to all employees who need them.
• Flexible Independent Contractor Agreement: Unlock the benefits of flexibility, autonomy, and entrepreneurial opportunities. Benefit from tax advantages, networking opportunities, reduced employment obligations, and the freedom to work from anywhere. Read more about it here: https://docs.google.com/document/d/1tzxGX4Uu7Ts_HCLFXESKLnKaaBfVCPf1f9AYZPrkjJM/preview?tab=t.0

Be part of our fast-growing team and seize this excellent opportunity for personal and professional growth!

Interview Process

After submitting your application, we conduct a thorough review which typically takes 3 to 5 days, but may occasionally take longer due to the volume of applications received. If we see a potential fit, we proceed with the following steps:

• Recruiter Screening (40 minutes)
• Technical Interview (60 minutes)
• Final Interview (60 minutes)

Life at Ruby Labs

At Ruby Labs, we move fast, aim high, and expect the same from our team. We’re not here to play small—we’re here to build, grow, and win. That means we look for people who are ambitious, driven, and ready to give their best every single day.

This is a place for individuals who thrive under pressure, embrace challenges, and see opportunity in every obstacle. If you’re hungry to achieve, motivated by impact, and want to grow at the speed of your own ambition, Ruby Labs offers the platform to make it happen.

Here, effort is matched with reward. We recognize those who go all in and deliver results, and we create space for people who want more—more responsibility, more growth, and more success.