Senior Software Engineer, Growth

Apollo.io is the leading go-to-market solution for revenue teams, trusted by over 500,000 companies and millions of users globally, from rapidly growing startups to some of the world's largest enterprises. Founded in 2015, the company is one of the fastest growing companies in SaaS, raising approximately $250 million to date and valued at $1.6 billion. Apollo.io provides sales and marketing teams with easy access to verified contact data for over 210 million B2B contacts and 35 million companies worldwide, along with tools to engage and convert these contacts in one unified platform. By helping revenue professionals find the most accurate contact information and automating the outreach process, Apollo.io turns prospects into customers. Apollo raised a series D in 2023 and is backed by top-tier investors, including Sequoia Capital, Bain Capital Ventures, and more, and counts the former President and COO of Hubspot, JD Sherman, among its board members. **This is a Permanent role ("Umowa o pracę") and not a B2B contract** As a Senior Software Engineer on the Growth team , you will be a critical part of our growing company, working at the intersection of engineering, product, marketing, and data science to accelerate product growth through rapid experimentation, data analysis, and scalable technical solutions. You’ll implement and drive best practices in technology, architecture, and process while optimizing funnels, automating growth loops, and shipping features that drive measurable impact. You’ll have the chance to work in an open and collaborative environment, receive and give hands-on mentorship, and have opportunities to grow and accelerate your career. You love both learning and teaching, enjoy working cross-functionally to solve hard problems, and strive for quality — obsessing over automation, performance, and squashing any bugs that sneak through. Our tech stack: Ruby/RoR, React.js, TypeScript, Redux, Node.js, Python, MongoDB, Elasticsearch, Ansible, Terraform, Grafana, Kibana, Docker, Kubernetes, AWS/GCP, GitHub Actions. Daily Adventures and Responsibilities • Develop and execute engineering strategies that enable rapid experimentation and data-driven decision-making • Collaborate cross-functionally with Product, Design, Marketing, Data Science, and Engineering to optimize key growth metrics and contribute to core product initiatives • Architect and build scalable systems that support growth initiatives, such as onboarding flows, personalization engines, and viral loops • Implement A/B testing and data instrumentation to ensure accurate tracking and measurement of experiments • Leverage automation and machine learning to optimize user engagement, reduce churn, and personalize user experiences • Produce clean, well-structured, well-documented code and implement pixel-perfect designs that work across browsers, per spec • Help maintain code quality, organization, automation, and continuous delivery • Ensure technical excellence through best practices in performance optimization, security, and scalability • Effectively communicate development progress or blockers to the product lead, engineering manager, and other stakeholders • Work effectively as part of a large global team; attend and engage in stand-ups, team meetings, and manager 1:1s • Give and receive constructive feedback and praise Competencies • Proactively acts without being told what to do; identifies areas of improvement and drives best practices to deliver high-quality, performant, scalable solutions • Takes ownership over everything shipped • Communicates effectively, clearly, and concisely — technical and non-technical, written and verbal — and actively listens to ensure understanding • Helps teammates overcome obstacles, resolve blockers, a