Senior Fullstack Engineer, Channel Expansion

Smartlyio; Helsinki; On-site; EUR 60,000 - 80,000; Full time

Benefits offered by this job

Healthcare packages

Mental health services

Performance-based rewards

Flexible hybrid workplace

Job summary

Smartlyio in Helsinki is looking for a Senior Fullstack Engineer to enhance their multi-channel advertising platform. You will be responsible for designing systems, building integrations, and collaborating with major partners like Google and Spotify.

The role emphasizes ownership of complex challenges and encourages mentorship within the team. You will work in a hybrid setup, emphasizing both collaboration and work-life balance.

Smartlyio offers competitive compensation, equity options, and a global culture that values diversity.

Qualifications

• Strong experience building production-grade systems with Node.js and TypeScript.
• Solid frontend experience with React and modern web development practices.
• Proven ability to build scalable systems handling high data volumes.

Responsibilities

• 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 processing large volumes of campaign and performance data.

Skills

Node.js

TypeScript

React

Distributed systems

Event-driven architectures

Data processing

Job description

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. We’re hiring for multiple positions across a range of seniority levels, and we’ll align the role scope and level based on each candidate’s experience during the hiring process.

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.

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.