Senior Backend Product Engineer - Go and/or Python (all genders)

About the Role: What’s in the Box

The service provider will join an autonomous, cross-functional squad accountable for a product domain end to end, with flexibility to transition between teams and projects as technical objectives and business priorities evolve.

Technical domains include:

• Marketing Customer Profile squad: Builds AI-powered backend systems that automate campaign execution end to end, from content generation and validation to multi-channel delivery across email, SMS, and push.
• Conversions Tribe: Supports Reachable Audience and Personalization initiatives, building systems that power customized user journeys at scale.

Across all domains, the technical profile consists of highly available, event-driven distributed systems serving global architectures. This role does not include people management responsibilities.

What You’ll Do: The Recipe

• Take the technical lead on backend-heavy product problems, designing, building, and operating reliable services and systems at scale under a full DevOps model.
• Build event-driven systems using messaging technologies such as Kafka, RabbitMQ, or AWS SQS/SNS, and expose data through clean REST and gRPC interfaces.
• Work with Docker, Kubernetes container orchestration, and CI/CD automated deployment pipelines.
• Maintain robust testing from unit tests through full end-to-end coverage.
• Collaborate within cross-functional agile teams including product leads, frontend engineers, designers, and data teams.
• Provide technical guidance and support to team members and participate in code and architecture reviews.
• Use modern AI tools and workflows, such as Claude and Cursor, to increase engineering productivity.
• Work beyond your specialization when the problem demands it.
• Operate, instrument, monitor, and improve systems in production.

What You’ll Bring: The Ingredients

• Hands-on experience with AI tooling, such as Claude Code, Cursor, and Copilot, beyond casual experimentation; daily use of AI agents and practical understanding of context quality and boundaries for AI-generated work.
• Strong fluency in Go or Python and production experience building distributed systems, including event-driven and asynchronous flows, clear service contracts, and design for partial failure.
• High proficiency in one stack, willingness to expand technical knowledge into Go, and ownership of observability and the data layer.
• Experience building, deploying, and operating critical backend services in production.
• Technical comfort with distributed systems, messaging queues, containerization, and modern deployment infrastructure.
• Strong software engineering instincts, including practical use of TDD, BDD, or DDD and sound technical trade-offs.
• Excellent communication skills for an international, multidisciplinary technical environment.
• Full ownership, product sense, a bias to ship, and the ability to support product decisions with data and user evidence.

What We Offer: The Toppings

• Collaboration with experienced engineers and product partners across international teams in a culture of active knowledge sharing.
• The opportunity to build and operate modern systems at global scale, supporting millions of customers and complex supply-chain operations.
• Technical, product, and design leadership opportunities to influence architecture, quality, and ways of working in an autonomous, product-led setup.
• End-to-end development and delivery ownership, from problem definition to production, with a focus on long-term scalability.
• Access to a workspace in central Warsaw with showers, breakout zones, outdoor space, cycle parking, and refreshments.