Senior Software Engineer, Design Systems

📍 Job Overview

Job Title: Senior Software Engineer, Design Systems

Company: Smartly

Location: Helsinki, Uusimaa, Finland

Job Type: Full-time

Category: Software Engineering / Design Systems

Date Posted: 2026-06-05

Experience Level: Senior (5-10 years)

Remote Status: Hybrid

🚀 Role Summary

• Drive the evolution and adoption of Smartly's Design System, ensuring UI consistency and developer efficiency across the platform.

• Develop and maintain customer-facing features that enhance user onboarding, product discovery, and overall customer success.

• Optimize frontend build, release, and deployment pipelines to foster reliable and high-velocity development cycles.

• Collaborate cross-functionally with product, design, and engineering teams to deliver impactful user experiences.

📝 Enhancement Note: While the title is "Senior Software Engineer, Design Systems," the responsibilities clearly indicate a strong focus on customer-facing feature development and platform functionality, particularly within the media and advertising technology domain. This role is not solely about design systems but leverages design systems as a core enabler for broader product development and customer experience enhancement. The emphasis on onboarding and customer success suggests a critical role in the user journey, bridging technical implementation with business outcomes.

📈 Primary Responsibilities

• Extend and maintain Smartly's Design System library, ensuring reusable components and patterns support consistent, high-quality user experiences across the entire platform.

• Partner closely with UI/UX designers to refine and improve frontend development workflows, tooling, and collaborative processes, accelerating design-to-implementation cycles.

• Champion and drive Design System adoption across various product areas by enhancing shared components, providing clear implementation guidance, and supporting development teams.

• Own, manage, and continuously improve the frontend build, release, and deployment processes, ensuring reliability, scalability, and efficiency for development and delivery pipelines.

• Develop and implement key customer-facing features that directly contribute to improved customer onboarding, product adoption rates, and long-term customer success outcomes.

• Contribute significantly to frontend architecture decisions, focusing on creating maintainable, scalable, and high-performance solutions that align with business objectives.

• Work collaboratively across the Smartly application to integrate features that surface critical insights, actionable recommendations, timely notifications, and important alerts to enhance the overall customer experience.

• Engage with engineers, product managers, designers, and the Engineering Manager to foster technical excellence and ensure alignment of engineering efforts with business impact goals.

📝 Enhancement Note: The responsibilities highlight a blend of specialized Design System work with broader full-stack feature development. The emphasis on "owning" build/release processes and contributing to "frontend architecture decisions" indicates a senior-level expectation for technical leadership and strategic input beyond just component development. The focus on customer success outcomes suggests a need for business acumen and understanding of user journey optimization.

🎓 Skills & Qualifications

Education:

• Bachelor's degree in Computer Science, Engineering, or a related field, or equivalent practical experience. Experience:

• 5-10 years of professional experience in software engineering, with a significant focus on frontend development and system design.

• Demonstrated experience in owning technical initiatives from conception through implementation and release. Required Skills:

• Proficiency in building modern, sophisticated web applications using React and TypeScript.

• Proven experience in designing, building, and maintaining reusable UI component libraries or comprehensive Design Systems.

• Solid understanding of frontend architecture principles, including best practices for performance, security, and maintainability.

• Experience with testing frameworks such as Vitest, React Testing Library, or similar tools for robust unit and integration testing.

• Strong collaboration skills, with a proven ability to work effectively with cross-functional teams including designers, product managers, and fellow engineers.

• A pragmatic and results-oriented approach to problem-solving and a commitment to the continuous improvement of engineering practices. Preferred Skills:

• Familiarity with backend development concepts and practices, particularly using Node.js and TypeScript.

• Experience with web accessibility standards and implementation (WCAG).

• Knowledge of frontend performance optimization techniques.

• Experience in improving UI development workflows and tooling.

• Understanding of CI/CD principles and experience with build and deployment processes.

📝 Enhancement Note: The "5-10 years" experience level for a "Senior" role is standard. The emphasis on React, TypeScript, and Design Systems is explicit. The inclusion of Node.js and TypeScript for backend familiarity, along with testing frameworks like Vitest and React Testing Library, points towards a modern, full-stack-oriented frontend role. The preferred skills suggest a candidate who can contribute to the broader engineering ecosystem beyond just UI components.

📊 Process & Systems Portfolio Requirements

Portfolio Essentials:

• Showcase projects demonstrating expertise in building and maintaining Design Systems or robust UI component libraries, highlighting reusability and scalability.

• Include examples of customer-facing features developed, emphasizing the impact on user experience, onboarding, or product adoption.

• Present case studies of frontend architecture contributions or significant technical initiatives owned from design to release.

• Demonstrate experience with testing strategies and the implementation of automated tests for frontend applications. Process Documentation:

• Detailed documentation of your approach to UI component development, including versioning, documentation standards, and contribution guidelines.

• Examples of how you have improved UI development workflows or design-to-code handoff processes.

• Evidence of contributions to or ownership of frontend build, release, and deployment processes, including automation and efficiency improvements.

• Case studies detailing how you have driven Design System adoption within a team or organization.

📝 Enhancement Note: For a Senior Software Engineer role focusing on Design Systems and feature development, a portfolio is crucial. It should not just list projects but demonstrate a deep understanding of process, ownership, and impact. The emphasis here is on showcasing not just the what but the how and why behind their work, particularly concerning scalable component development, workflow optimization, and feature delivery.

💵 Compensation & Benefits

Salary Range:

• Given the Senior level, location (Helsinki, Finland), and the tech industry, a competitive salary range for a Senior Software Engineer in Helsinki is estimated to be between €65,000 - €90,000 annually. This estimate is based on industry benchmarks for similar roles in Western European tech hubs, considering the specific skills (React, TypeScript, Design Systems) and the company's likely stage of growth as a prominent AdTech firm. Benefits:

• Healthcare Packages: Comprehensive health coverage for employees and potentially dependents.

• Mental Health Services: Access to resources and support for mental well-being.

• Paid Holidays: Generous paid time off, encouraging work-life balance.

• Family Leave: Support for employees during significant life events like the birth or adoption of a child.

• Equity Options: Potential to own a stake in the company's success through stock options.

• Performance-based Rewards: Recognition and compensation tied to individual and company achievements.

• Competitive Compensation: A salary that reflects the candidate's skills, experience, and the market value for senior engineering talent.

• Career Development Opportunities: Access to training, conferences, and internal growth programs.

• Flexible Hybrid Workplace: The ability to balance in-office collaboration with remote work flexibility.

• Work Abroad Option: Opportunity to work remotely from other locations for up to 30 days per year, offering global flexibility.

Working Hours:

• Standard full-time working hours are expected, typically around 40 hours per week. The hybrid model allows for flexibility in structuring these hours, balancing collaborative time with focused individual work.

📝 Enhancement Note: The salary range is an estimation for Helsinki, Finland, based on the Senior Software Engineer title and the specified skills. The benefits listed are directly extracted from the provided text, highlighting a strong emphasis on employee well-being, financial rewards, and flexible work arrangements.

🎯 Team & Company Context

🏢 Company Culture

Industry: AI-powered Advertising Technology (AdTech)

Company Size: 750+ employees globally. This size suggests a well-established company with robust processes but still agile enough to foster innovation and offer significant impact opportunities for senior engineers.

Founded: Smartly was founded with a vision to transform ad experiences, growing into a significant player managing substantial ad spend and creative generation. This history implies a culture of continuous innovation and adaptation within the fast-paced AdTech landscape.

Team Structure:

• The role is within the "Platform Functionality (Media)" product group, suggesting a focus on core platform capabilities that enable media buying and ad campaign management.

• This group likely comprises engineers, product managers, and designers working collaboratively on specific product areas.

• Reporting to an Engineering Manager, the Senior Software Engineer will be part of a team that values technical excellence and business impact. Methodology:

• The company's AdTech focus implies a data-driven approach, leveraging AI and analytics to optimize advertising campaigns and creative outputs.

• Emphasis on "technical excellence and business impact" suggests a methodology that balances robust engineering practices with a clear understanding of customer needs and market dynamics.

• The commitment to continuous improvement of engineering practices indicates an iterative and agile development approach.

Company Website: https://www.smartly.io/careers

📝 Enhancement Note: The company context is tailored to Smartly's position as a leader in AI-powered AdTech. The size and founding history are interpreted in terms of their implications for culture and opportunity. The team structure and methodology are inferred from the role description and industry context, emphasizing collaboration and data-driven innovation.

📈 Career & Growth Analysis

Operations Career Level: Senior Software Engineer, Design Systems. This level signifies a technical expert responsible for architecting, developing, and maintaining critical frontend systems. The role requires not only strong coding skills but also the ability to influence technical direction, mentor junior engineers, and drive adoption of best practices.

Reporting Structure: The role reports to an Engineering Manager within the Platform Functionality (Media) product group. This structure allows for direct technical guidance and career development support while ensuring alignment with broader product and company objectives.

Operations Impact: This role has a significant impact on Smartly's business by:

• Ensuring a consistent and intuitive customer experience across the platform, directly influencing customer satisfaction and retention.

• Improving onboarding and product adoption, accelerating time-to-value for new customers and driving revenue growth.

• Enhancing developer productivity through robust Design Systems and optimized workflows, leading to faster feature delivery and reduced technical debt.

• Contributing to the scalability and maintainability of the platform, supporting the company's continued global growth and innovation in the AdTech space. Growth Opportunities:

• Technical Specialization: Deepen expertise in Design Systems, frontend architecture, and performance optimization, potentially becoming a Principal Engineer or Architect.

• Leadership Development: Transition into technical leadership roles, such as Tech Lead for a product team or Engineering Manager, by leveraging mentorship and project ownership experience.

• Cross-functional Exposure: Gain broader experience in product strategy, design collaboration, and backend integration, preparing for more holistic engineering roles.

• Industry Expertise: Develop in-depth knowledge of the AdTech industry, AI applications in advertising, and global market dynamics.

📝 Enhancement Note: This section translates the "Senior Software Engineer, Design Systems" title into a clear operational context, detailing the scope of responsibility, impact on business metrics (customer satisfaction, adoption, revenue, efficiency), and specific avenues for career progression within Smartly and the broader AdTech industry.

🌐 Work Environment

Office Type: Hybrid Workplace. This model combines the benefits of in-office collaboration (team meetings, brainstorming, social interaction) with the flexibility of remote work, allowing for focused individual tasks.

Office Location(s): Helsinki, Uusimaa, Finland. This location provides access to a vibrant tech ecosystem and a skilled talent pool.

Workspace Context:

• Collaborative Environment: The hybrid model encourages planned office days for team synchronization, strategic discussions, and fostering team cohesion.

• Operations Tools & Technology: Access to a modern technology stack, including advanced frontend development tools, CI/CD pipelines, and collaboration platforms.

• Team Interaction: Opportunities for regular interaction with engineers, designers, and product managers through scheduled meetings, pair programming, and informal discussions.

Work Schedule:

• A standard 40-hour work week is typical, with flexibility in daily scheduling to accommodate personal needs and optimize productivity. The hybrid nature allows for adaptation to different work styles and preferences.

📝 Enhancement Note: The work environment description is tailored to the "Hybrid" status and the "Helsinki" location, focusing on how these elements contribute to a productive and collaborative atmosphere for a software engineering role.

📄 Application & Portfolio Review Process

Interview Process:

• Initial Screening: A brief call with a recruiter to assess basic qualifications, cultural fit, and role alignment. Prepare to discuss your background and interest in Smartly.

• Technical Interview(s): Typically involves coding challenges (live or take-home), system design discussions, and deep dives into your experience with React, TypeScript, Design Systems, and frontend architecture. Be ready to whiteboard solutions and explain your thought process.

• Portfolio Review & Discussion: A dedicated session to walk through selected projects from your portfolio. Focus on explaining your role, the technical challenges, the solutions implemented, and the impact achieved. This is where your Design System and feature development expertise will be scrutinized.

• Behavioral & Team Fit Interview: Assess your collaboration skills, problem-solving approach, communication style, and how you align with Smartly's values. Prepare examples using the STAR method (Situation, Task, Action, Result).

• Hiring Manager/Team Lead Interview: Final discussion to ensure alignment on expectations, answer any remaining questions, and confirm suitability for the team dynamic.

Portfolio Review Tips:

• Curate Strategically: Select 2-3 key projects that best showcase your experience with Design Systems, complex feature development, and frontend architecture.

• Focus on Impact: For each project, clearly articulate the problem you solved, your specific contributions, the technologies used, and the measurable outcomes (e.g., improved adoption, reduced development time, enhanced consistency).

• Explain Your Process: Detail your approach to component design, implementation, testing, and documentation. If you improved workflows, explain how.

• Highlight Design System Contributions: Emphasize your role in building, maintaining, or driving adoption of Design Systems, including challenges faced and how you overcame them.

• Be Prepared for Technical Deep Dives: Anticipate questions about your architectural decisions, testing strategies, and performance considerations.

Challenge Preparation:

• Coding Exercises: Practice common algorithms and data structures, focusing on clean, efficient, and well-tested JavaScript/TypeScript code.

• System Design: Prepare for discussions on designing scalable and maintainable frontend systems, including considerations for component architecture, state management, and API interactions.

• Design System Scenarios: Think about how you would approach common Design System challenges, such as component versioning, documentation, adoption strategies, and handling design inconsistencies.

📝 Enhancement Note: This section provides actionable advice for navigating the interview process at a company like Smartly, specifically for a Senior Software Engineer role. It emphasizes the importance of a well-curated portfolio that demonstrates impact and process, particularly concerning Design Systems and feature development.

🛠 Tools & Technology Stack

Primary Tools:

• React: The core JavaScript library for building user interfaces. Proficiency is essential for component development and feature implementation.

• TypeScript: For statically typed JavaScript development, enhancing code quality, maintainability, and developer productivity.

• Node.js: Likely used for backend services, build tools, and potentially server-side rendering. Familiarity is a strong asset.

• Design System Libraries: Experience with tools and methodologies for building and managing component libraries (e.g., Storybook, Styleguidist).

Analytics & Reporting:

• Vitest/Jest/React Testing Library: Essential for writing unit, integration, and end-to-end tests to ensure code quality and application stability.

• Web Analytics Tools: (e.g., Google Analytics, Mixpanel) Potentially used to monitor feature adoption and user behavior, informing development priorities.

CRM & Automation:

• Version Control: Git is standard for code management and collaboration.

• CI/CD Tools: (e.g., Jenkins, GitLab CI, GitHub Actions) For automating build, test, and deployment processes.

• Project Management Tools: (e.g., Jira, Asana) For task tracking, sprint planning, and workflow management.

📝 Enhancement Note: This section outlines the likely technology stack based on the job description's requirements and industry standards for a modern frontend role at an AdTech company. It focuses on core development tools, testing frameworks, and relevant backend technologies.

👥 Team Culture & Values

Operations Values:

• Technical Excellence: A commitment to high-quality, scalable, and maintainable code, with a strong emphasis on best practices in frontend development and system design.

• Customer Focus: Prioritizing the customer experience, evident in the drive for consistent UI, improved onboarding, and features that directly contribute to customer success.

• Collaboration: Valuing teamwork, open communication, and effective partnerships with designers, product managers, and fellow engineers to achieve shared goals.

• Continuous Improvement: A proactive mindset towards refining engineering practices, optimizing workflows, and adopting new technologies to enhance efficiency and impact.

• Pragmatism: Applying a balanced and realistic approach to problem-solving, focusing on delivering tangible business value and iterating effectively.

Collaboration Style:

• Cross-functional Integration: Working closely with Product and Design to translate requirements and designs into robust technical solutions.

• Peer Collaboration: Engaging in code reviews, knowledge sharing sessions, and pair programming to elevate team capabilities and ensure code quality.

• Feedback Exchange: Openness to giving and receiving constructive feedback to foster growth and improve processes and outcomes.

• Proactive Communication: Maintaining clear and timely communication regarding progress, challenges, and potential roadblocks.

📝 Enhancement Note: This section extrapolates Smartly's likely team culture and values based on the provided job description and common traits of successful tech companies, particularly those emphasizing product quality and customer success in a competitive market like AdTech.

⚡ Challenges & Growth Opportunities

Challenges:

• Design System Scalability: Ensuring the Design System remains effective and maintainable as the platform and product suite grow, requiring thoughtful architecture and governance.

• Adoption Across Teams: Driving consistent adoption of the Design System and best practices across multiple engineering teams with varying priorities and existing codebases.

• Balancing Feature Velocity & System Health: Managing the demands of delivering new customer-facing features while dedicating sufficient time to maintaining and evolving the Design System and core platform components.

• Evolving AdTech Landscape: Staying ahead of rapid changes in advertising technology, user behavior, and platform requirements that may necessitate architectural shifts or new feature integrations.

Learning & Development Opportunities:

• Advanced Frontend Architecture: Opportunities to deepen expertise in complex frontend patterns, micro-frontends, and performance optimization strategies.

• AI and AdTech Domain Knowledge: Gaining specialized knowledge in AI applications within advertising and the dynamics of the global AdTech market.

• Technical Leadership: Developing skills in mentoring, technical strategy, and influencing product direction through hands-on experience and potential leadership roles.

• Cross-functional Skill Development: Learning more about product management, UX design principles, and business strategy through close collaboration.

📝 Enhancement Note: This section identifies potential challenges inherent in a Senior role focused on Design Systems and platform development within the AdTech industry, and pairs them with specific learning and growth opportunities that leverage these challenges as catalysts for professional development.

💡 Interview Preparation

Strategy Questions:

• Design System Philosophy: "Describe your approach to building and evolving a Design System. What are the key principles you adhere to, and how do you ensure adoption across diverse teams?" (Prepare to discuss component architecture, theming, documentation, and governance.)

• Feature Ownership & Impact: "Walk me through a significant customer-facing feature you owned from concept to launch. What was the business problem, what technical challenges did you face, and what was the measurable impact?" (Focus on demonstrating end-to-end ownership and customer-centric development.)

• Process Improvement: "Tell me about a time you improved a frontend development workflow, build process, or collaboration method. What was the situation, your contribution, and the outcome?" (Highlight your ability to identify inefficiencies and implement practical solutions.)

Company & Culture Questions:

• Smartly's Mission: "What interests you about Smartly's mission and its role in the AI-powered AdTech space?" (Research Smartly's products, market position, and recent news.)

• Hybrid Work Philosophy: "How do you approach collaboration and productivity in a hybrid work environment?" (Be ready to discuss strategies for effective remote and in-office collaboration.)

• Technical Decision-Making: "Describe a challenging technical decision you had to make. How did you evaluate options, and what factors influenced your final choice?" (Showcase your analytical and decision-making process.)

Portfolio Presentation Strategy:

• Structure Your Narrative: For each project, clearly outline the problem statement, your specific role and contributions, the technical solutions implemented (especially regarding Design Systems/components), and the quantifiable results or impact.

• Demo Key Aspects: Be prepared to share screen or provide links to live examples if possible, showcasing UI components, feature functionality, or system architecture.

• Highlight Design System Value: Explicitly detail how your Design System work contributed to consistency, efficiency, or scalability. Discuss your process for creating reusable components and documentation.

• Focus on Senior-Level Contributions: Emphasize your architectural thinking, problem-solving skills, and ability to drive initiatives, rather than just coding tasks.

📝 Enhancement Note: This section provides targeted interview preparation advice, including example questions and portfolio presentation strategies tailored to the specifics of a Senior Software Engineer role focused on Design Systems within the AdTech industry.

📌 Application Steps

To apply for this Senior Software Engineer, Design Systems position:

• Submit your application through the Smartly careers portal.

• Portfolio Customization: Tailor your resume and portfolio to prominently feature your experience with React, TypeScript, Design Systems, UI component libraries, and any customer-facing features you've developed. Showcase specific examples of design system adoption initiatives and their impact.

• Resume Optimization: Ensure your resume clearly highlights your 5-10 years of relevant experience, focusing on achievements and responsibilities that align with the job description, using keywords like "Design Systems," "React," "TypeScript," "Frontend Architecture," and "UI Development."

• Interview Preparation: Practice articulating your experience with Design Systems, your approach to technical challenges, and your collaborative skills. Prepare concise case studies for your portfolio walkthrough, focusing on impact and process.

• Company Research: Familiarize yourself with Smartly's AI-powered advertising platform, its market position, and its company culture. Understand how the Design System role contributes to their overall mission of transforming ad experiences.

⚠️ Important Notice: This enhanced job description includes AI-generated insights and operations industry-standard assumptions. All details should be verified directly with the hiring organization before making application decisions.