Senior Software Engineer

We are currently seeking an experienced Backend Software Engineer to join the Agency team at our Kraków Hub. Our ideal candidate is someone who thrives in a high-growth environment with rapidly evolving needs. This individual will contribute to our Agency platform — powering ActiveCampaign's partner and reseller ecosystem — working across multi-account management, partner tooling, and API services. The role spans our PHP backend and Python-based agentic AI workflows, with a strong emphasis on building AI-native capabilities into the Agency product experience. You don't have to check all the checkboxes in the job description. We're looking for driven and curious engineers who are open about learning new technologies and solving problems.

What your day could consist of::
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Agency Platform & AI Development Building and enhancing features across the Agency platform including partner tooling, multi-account management, and API services in PHP Designing and implementing agentic AI workflows that automate and enhance partner and reseller experiences Integrating LLM-powered capabilities into core Agency features — from intelligent recommendations to automated partner operations Contributing to our Python-based AI agent development and iteration Driving productization — evolving Agency features to be more scalable and configurable for diverse partner needs Maintaining and evolving legacy codebases while driving modernization efforts

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Collaboration Working with cross-functional teams including Product, Design, and other engineering squads Engaging in pairing and code reviews Participation in the on-call rotation for incidents

What we're looking for::
Required:

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4+ years of work experience in a backend software engineering role

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Demonstrated knowledge of the challenges of scaling SaaS systems

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Experience writing production code in PHP following accepted coding standards

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Experience with Python for backend services or AI/agentic workflows

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Familiarity with DB technologies: MySQL, DynamoDB, Redis

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Strong problem-solving skills and ability to work across multiple codebases and technologies

Nice to have:

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Experience building or integrating AI/ML systems, LLM-powered features, or agentic workflows

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Deeper database expertise — query optimization, data modeling, schema design, or experience with data pipelines and analytics infrastructure

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Familiarity with CI/CD practices and patterns

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Knowledge of AWS (or any public cloud)

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Experience with API design and platform/partner ecosystem development

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Track record of identifying and delivering performance improvements in production systems

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Experience with SaaS productization

This is an exciting time to join ActiveCampaign as we build out our new office in Poland. You will be a large part of developing our office culture in this new Krakow hub location.

About ActiveCampaign:
ActiveCampaign is the autonomous marketing platform for people at the heart of the action. It empowers teams to automate their campaigns with AI agents that imagine, activate, and validate–freeing them from step-by-step workflows and unlocking limitless ways to orchestrate their marketing.

With AI, goal-based automation, and 1,000+ app integrations, agencies, marketers, and owners can build cross-channel campaigns in minutes–fine-tuned with billions of data points to drive real results for their unique business.

ActiveCampaign is the trusted choice to help businesses unlock a new world of boundless opportunities–where ideas become impact and potential turns into real results.

As a global multicultural company, we are proud of our inclusive culture which embraces diverse voices, backgrounds, and perspectives. We don’t just celebrate our differences, we believe our diversity is what empowers our innovation and success. You can find out more about our DEI initiatives here.

Perks and Benefits:
At ActiveCampaign, we prioritize employees’ well-being and professional growth by cultivating a culture centered on collaboration and innovation. When you join our team, you’ll not only have the opportunity to make a significant impact, but also enjoy a range of benefits tailored to support your personal and career development.

Here are some of the benefits we offer:
-Comprehensive Health & Wellness: Top-tier benefits package that includes medical and dental benefits paid 100% by ActiveCampaign for you and 50% for your dependents, and reimbursements on vision expenses. In addition, employees receive complimentary access to telehealth services, and a free subscription to Calm.
-Growth & Development: Access to LinkedIn Learning, professional development programs, and career growth opportunities in a fast-growing organization.
-Generous Paid Time Off: Recharge and take the time you need to maintain work-life balance.
-Total Rewards: Pension scheme with matching up to 1.5% of your contribution, MultiSport Plus card to support your active lifestyle, home office stipend to cover your commuter or work from home expenses, and a four-week paid sabbatical with bonus after five years.
-Collaborative Culture: Work alongside brilliant, passionate colleagues in an environment that values innovation, teamwork, and mutual support.

ActiveCampaign is an equal opportunity employer. We recruit, hire, pay, grow, and promote no matter of gender, race, ethnicity, sexual orientation, marital status, political opinion, national origin, social origin, parentage, workers union membership, economic status, religion, age, health condition, disability or any other grounds protected by law.

Our Employee Resource Groups (ERGs) strive to foster a diverse inclusive environment by supporting each other, building a strong sense of belonging, and creating opportunities for mentorship and professional growth for their members.