Senior Fullstack Engineer, Channel Expansion at Smartlyio

We’re looking for a Senior Fullstack Engineer to join Smartly and help shape the future of our multi-channel advertising platform. You’ll be working on expanding Smartly into both new and existing advertising channels. Depending on the team, this can mean greenfield development of new integrations or evolving and scaling established ones like Pinterest. While we can’t share all the details yet, this is a highly strategic area for the company with strong leadership visibility and direct revenue impact. Whether you’re building something new or improving existing integrations, the work goes beyond incremental changes. You’ll be building new capabilities, improving existing ones, and helping shape how different channels are integrated into our platform at scale. In this role, you’ll design systems that power automation for some of the world’s largest advertisers. You’ll work closely with partners like Google, Reddit and Spotify, building deeply integrated solutions that enable customers to launch, optimize, and iterate campaigns efficiently. You’ll also have the opportunity to explore how AI and automation shape the future of ad tech, and turn those ideas into production-grade systems. This role is about ownership and technical influence. You’ll contribute to architectural direction, make trade-offs that balance scalability and product needs, and collaborate across teams to create a unified platform experience across channels. Our tech stack • Backend: Node.js, TypeScript • Frontend: React, TypeScript • Infrastructure: PostgreSQL, RabbitMQ, Redis, Kubernetes • Architecture: Distributed systems, event-driven services, large-scale data processing What you’ll do • Own the design and implementation of new platform integrations end-to-end • Design and operate distributed, data-intensive systems and microservices at scale • Build automation systems that process large volumes of campaign and performance data • Develop and evolve client-facing APIs and backend services • Drive architectural decisions and contribute to long-term technical direction • Work across teams to align on shared patterns and unify channel behavior within the platform • Partner closely with product and design to shape solutions, not just implement them • Mentor other engineers and raise the bar for engineering quality and practices What we’re looking for • Strong experience building and operating production-grade systems with Node.js and TypeScript • Solid frontend experience with React and modern web development practices • Experience designing distributed systems and working with asynchronous, event-driven architectures • Proven ability to build scalable systems that handle high data volumes • Ability to take ownership of complex problems and drive them from concept to production • Strong collaboration skills and experience working across teams and disciplines • Interest in mentoring and contributing to team-level engineering practices • Ability and willingness to work in a hybrid setup from our Helsinki office (3 days per week) What We Offer You At Smartly, we offer a place where you can advance your career. Here, you'll find: An Inclusive Global Culture: Join a team of over 750 Smartlies, representing more than 60 nationalities across 24 locations in 13 countries. We cultivate a culture built on trust, transparency, and open feedback, where diverse perspectives are valued and encouraged. Global Impact: Contribute to a company making a global impact, directly influencing our customers' success and business growth. Focus on Wellbeing: We prioritize your health with healthcare packages, mental health services, and a commitment to work-life balance through paid holidays and family leave. Comprehensive Rewards: Benefit from equity options, performance-based rewards, competitive compensation, and career development opportunities. Flexible Hybrid Workplace: Experience a hybrid work model, balancing office collaboration with remote work, and the option to work abroad for up to 30 days annually. Smartly is committed to being a great place for growth-minded individuals to thrive. Explore more in our Culture Handbook! Apply Now and Build Your Future with Smartly! Curious what it’s like to work at Smartly? Visit our Careers page to see how we grow, collaborate, and make impact together #LI-HYBRID About Smartly Smartly is the AI-powered advertising technology company transforming ad experiences for brands and their consumers. Our comprehensive advertising platform seamlessly integrates the capabilities of media, creative, and intelligence to power more than 800 billion impressions and generate more than 300 billion creatives annually, delivering tangible business outcomes for brands and advertisers. Smartly is the only company in the industry recognized as a Leader in The Forrester Wave: Creative Advertising Technologies with PwC validating the results it delivers for brands. We manage creative and media for 700+ brands worldwide and $6B in ad spend across the largest media platforms, including Facebook, Google, Instagram, Pinterest, Snap, and TikTok. Our end-to-end technology, unmatched access to media platforms and exceptional customer service help Fortune 500 brands to reach and engage consumers and learn what performs best.Smartly is a multinational and diverse team of 750+ Smartlies from 60+ nationalities, working in 13 countries. Together, we want to create and maintain an inclusive environment where everyone feels respected and heard. Our Diversity, Equity & Inclusion approach is at the heart of it. Visit Smartly to learn more. The processing of your information is described in our Candidate Privacy Notice.