Head of Customer Success

We don’t follow best practices, we set them!

We are looking for an experienced Head of Customer Success who will own and scale a portfolio of 150–200M PLN in annual revenue, lead a team of 3–5 Account Managers, and act as a bridge between business value and technical innovation.

The Head of Customer Success is responsible for maintaining strong client relationships, ensuring successful service delivery, and driving revenue growth through upselling, cross-selling, strategic account development, and team leadership. This role carries direct P&L accountability with ambitious year-over-year growth targets.

You will work directly with the Head of Engineering to articulate deeply technical business value propositions and position Callstack as a strategic technology & business partner - not a delivery vendor.

• Own the full revenue target for a 150 - 200M PLN portfolio with ambitious YoY growth goals. You are the single point of accountability for top-line performance.

• Drive upsells, account expansions, cross-sells, and end-to-end renewals to ensure consistent revenue growth across the entire portfolio.

• Build and execute mid- and long-term key account plans, including stakeholder mapping, competitive positioning, and expanding into new client divisions to unlock incremental revenue.

• Lead pricing strategy, contract negotiations, and commercial deal structuring for the largest and most complex engagements.

• Develop account strategies and roadmaps to strengthen long-term partnerships and maximize lifetime value.

• Personally own relationships with top-tier accounts. Lead regular executive-level 1:1s with key stakeholders and plan onsite visits to deepen partnerships.

• Build and maintain long-term relationships with key client stakeholders across all levels of the organization.

• Act as a bridge between clients and R&D, sharing technology trends and innovation insights to position Callstack as a strategic partner.

• Partner closely with the Head of Engineering to develop technical value propositions that elevate conversations from operational delivery to strategic transformation.

• Lead, coach, and develop a team of 3 - 5 Account Managers. Set performance expectations, run deal reviews, and build a high-performing commercial culture.

• Establish scalable account management processes, playbooks, and reporting cadences that drive consistency and predictability across the team.

• Monitor client financial situation monthly, map potential risks to current and future revenue, and execute churn prevention measures.

• Manage sales forecasting, pipeline reporting, account reporting, legal contracts, and the acquisition of case study approvals.

• Connect various client initiatives by providing cross-project context, market intelligence, and industry-level positioning.

• Drive referrals and stakeholder introductions to expand account footprint organically.

• Travel up to 25% of working time, including international travel (US, Europe, Asia), to build and deepen relationships with key clients and represent Callstack at industry events.