ActiveCampaign is seeking a Software Engineer to join our Kraków Hub and build production-ready AI agents for autonomous marketing. Our platform empowers businesses to automate their customer engagement — and we are now extending that with intelligent, agentic workflows that can reason, act, and adapt on behalf of our customers. Our first wave of agents is already in production. This role will drive the expansion, building the next generation of autonomous experiences across the full breadth of the platform.

You 'll work at the intersection of solid software engineering and applied AI — designing, building, evaluating, and operating agents that run at scale in a production marketing automation platform. This means engineering rigor comes first: agents need to be reliable, observable, performant, and safe before they are clever.

Our Kraków Hub houses multiple engineering teams — Forms, Integrations, Ecommerce, Agency, CRM, Mobile, CampaignsUI, and Content — working across different product pillars with a shared focus on building agentic workflows into all core functionalities across the platform. You will collaborate closely with these teams, understanding their domains and building agents that integrate seamlessly into the broader system,

This is not a pure research or ML role. We need engineers who can build — end to end — from prompt design through backend orchestration to frontend integration, and who can ship, measure, and iterate fast. Our environment moves quickly — we value high ownership, tight feedback loops, and close cross-functional collaboration. If you thrive in a hands-on, high-pace setting where you build, ship, and iterate rapidly, this role is for you.

What your day could consist of:

Designing and building production-grade AI agents and autonomous marketing workflows across the ActiveCampaign platform
Implementing multi-step agentic flows involving LLM orchestration, tool use, and integration with platform services
Working with LLM APIs (prompt engineering, response handling, evaluation) and building reliable, testable agent pipelines
Designing and running agent evaluations — building eval frameworks, defining quality metrics, and continuously measuring agent accuracy, reliability, and performance in production at scale
Monitoring and optimizing agent performance — latency, cost, token usage, error rates — and iterating rapidly based on production dataIterating on agent behavior based on user feedback, observability data, and quality metrics
Leveraging AI-assisted development tools and practices in your daily workflow — you don't just build AI features, you build with AI
Writing production-quality code in Python for agent services and backend orchestration
Contributing to PHP backend and frontend (React/Ember) integration points where agents interact with the core platform
Building and maintaining APIs, data flows, and service interfaces that agents depend on
Working iteratively — shipping code fast, learning from production, and improving continuously
Ensuring code quality through testing, code review, and adherence to engineering standards
Participating in on-call rotation for incidents related to agent services
Working closely with Product, Design, and domain engineering teams to define agent capabilities and user experiences
Engaging in pairing and code reviews across teams
Contributing to documentation of agent architectures, patterns, and best practices
Maintaining regular overlap with US-based teams (Chicago timezone) to ensure alignment and tight collaboration across the organization

What we're looking for:

2-4 years of experience in a software engineering role
Hands-on experience building and running AI agents or agentic workflows in a production environment — not just prototypes or side projects
Experience with agent evaluation and performance optimization — you know how to measure whether an agent is working well and how to make it better
Solid backend development skills in Python; working familiarity with PHP is a plus
Understanding of how to build reliable, testable, and observable systems
Active practitioner of AI-driven development — you use AI coding assistants and agentic development tools as part of how you work, not just what you build
Ability to work iteratively and ship code fast — you're comfortable with rapid release cycles and learning from production
Familiarity with DB technologies: MySQL, DynamoDB, Redis
Strong problem-solving skills and ability to work across multiple codebases and technologies
Fluent in English (B2 minimum)
Willingness to work flexible hours with regular afternoon availability to overlap with US Central timezone
Experience with agentic AI frameworks or multi-agent orchestration patterns
Familiarity with Model Context Protocol (MCP) or tool-use patterns for LLM agents
Experience building eval pipelines or quality measurement systems for LLM-based features
Frontend experience with React or EmberFamiliarity with AWS, CI/CD practices, and observability tooling
Understanding of prompt engineering, evaluation methodologies, or LLM fine-tuningExperience in SaaS, marketing automation, or CRM domain

What we offer:

A front-row seat in ActiveCampaign's AI-first transformation — you'll build the autonomous marketing agents customers interact with
Collaboration with experienced engineers across the Kraków Hub, including senior and staff-level technical leadership
An environment that values ownership, fast iteration, and learning by doing
Active investment in AI-first engineering practices and tooling
Hybrid work model from our Kraków office with flexibility to adjust working hours for collaboration with US-based teams (Chicago timezone overlap)

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.

Software Engineer, Agent Development