Product Manager - Developer Platform

Lead Software Engineer - AI Engineering

RTB House

Location: Poland We are:  RTB House is a global company that provides state-of-the-art marketing technologies for top brands and agencies worldwide. Our proprietary ad-buying engine is the first in the world to be powered entirely by Deep Learning algorithms, enabling advertisers to achieve outstanding results and meet their goals at every stage of the funnel. Join RTB House and lead our AI Engineering Lab, a team dedicated to pioneering innovation and boosting engineering productivity by leveraging the latest advancements in Agentic AI. We are looking for a hands-on technical leader with a strong, traditional software engineering background. In this role, you won't just be writing custom code from scratch. Our approach is highly pragmatic: we build internal tools, intelligent agents, and MCPs to supercharge our engineering workflows. A critical part of our philosophy is knowing when to leverage off-the-shelf products and existing frameworks versus when to architect and build custom solutions. We need a leader who can navigate this landscape and pick the absolute best solution for the task at hand. You will: * Lead & Mentor: Guide a small team of software engineers, fostering a culture of technical excellence, collaboration, and continuous improvement. Set and maintain high standards for code quality and system performance. * Drive Pragmatic Architecture: Design and develop distributed systems, internal productivity tools, and multi-agent architectures. You will own the "build vs. buy/integrate" decisions - choosing the right mix of off-the-shelf AI products, APIs, and custom-built components. * Innovate with Agentic AI: Spearhead the evaluation, prototyping, and integration of novel Agentic AI systems, LLMs, and Model Context Protocols (MCPs) to solve complex business and engineering problems. * Own the Execution: Manage the full development lifecycle from concept to production deployment. Ensure that the solutions we deploy are reliable, scalable, maintainable, and deliver real value. * Collaborate Cross-Functionally: Work closely with Product Manager, Engineering Managers, and broader engineering teams to align the Lab’s innovations with company strategy and platform requirements. Desired experience: * Strong Software Engineering Background: Minimum of 6 years of professional experience building, deploying, and operating complex, large-scale distributed systems (e.g., microservices, event-driven architectures). * Technical Leadership: Demonstrated experience defining technical roadmaps, mentoring engineers, leading code reviews, and driving high-level architectural decisions. * Programming Languages: High proficiency in Python is mandatory. Experience with at least one other language (such as Java, Go, TypeScript, or Scala) is highly preferred. * Solution Evaluation: Strong intuition and experience in evaluating third-party tools, frameworks, and vendor solutions to solve engineering problems efficiently rather than always building from scratch. * AI/ML Integration: Experience integrating large language models (LLMs) into production applications, alongside a basic understanding of the Machine Learning lifecycle and MLOps practices. Nice to have: * Direct experience building internal developer tools, custom Model Context Protocols (MCPs), or using Agentic AI frameworks (e.g., Vercel AI SDK, LangChain, AutoGen, Agent Development Kit). * Experience with cloud platforms (AWS, GCP, Azure) and containerization technologies (Docker, Kubernetes). * Familiarity with the ad-tech industry and real-time bidding (RTB) systems. We Offer: * Projects focused on extreme performance and high code quality – clean code and solid code reviews are our standard. * Collaboration within an interdisciplinary, self-sufficient team (including DevOps, database experts, backend developers, product designers, and QA engineers). * Access to modern technologies and the opportunity to apply them in large-scale, high-impact projects. * Cooperation based on B2B contract. * You can cooperate 100 % remotely or choose one of our office spaces in Warsaw or Cracow. Apply now! You don't need to tick every box to apply. If you are passionate about software engineering, send us your CV, and we'll review it.

Android Engineer - KMP

Sumup

Salary range: 15 000 - 20 100 PLN per month About the team SumUp’s Point-of-Sale (POS) solution empowers cafes, shops, bars, hair salons, and other businesses to operate efficiently and grow. It offers a wide range of features, including product catalogs, inventory management, business analytics, compliance support, and loyalty tools. Our POS solution integrates seamlessly into the SumUp SuperApp, which supports both our proprietary register hardware and mobile devices like tablets and phones. As an Android Developer, you’ll collaborate with a dynamic, cross-functional team of Product Managers, Product Designers, Engineering Managers, and fellow engineers. About the role We’re evolving toward a Kotlin Multiplatform (KMP) strategy, enabling shared development across Android and iOS. In this role, you’ll learn, refine, and help implement this technology, shaping the future of our mobile apps. You’re a developer who values user-centric design, precision, and seamless collaboration. You bring structure to communication and thrive in a cross-functional environment.  What you’ll do * Build new features for the item catalog within the SumUp SuperApp * Help improve the architecture of the application and contribute to our Kotlin Multiplatform strategy * Enhance and maintain our unified android app, distributed across 60+ countries, ensuring high-quality, scalable solutions * Shape the product’s evolution by identifying opportunities for improvement and contributing to daily decision-making * Write thorough documentation and implement robust testing for features before shipping * Collaborate closely with Designer, Product Manager and Android engineers to deliver a unified UX experience across platforms * Coach and mentor other engineers You’ll thrive in this role if: * You have 3+ years of experience in mobile engineering with Android and Kotlin. * You have 2+ years of experience working with Jetpack Compose. * You have a solid understanding of software design patterns (e.g., MVVM, MVI) and expertise in building modular, scalable app architectures. * You have good knowledge of reactive programming (Flow, Coroutines and Concurrency). * You have a strong grasp of testing best practices: knowing what to test, why, and how to write resilient tests. * You strive for clean code, and you are flexible to balance pragmatism and perfection. * You have a keen interest in multi-platform development using Kotlin Multiplatform. Why you should join SumUp: * 🌈 Commitment to Diversity and Inclusion: be part of a workplace that values and promotes diversity, fostering an inclusive environment where everyone's perspectives are respected and embraced  * 🚀 Enrollment onto our VSOP program: you will own a stake in SumUp’s future success  * 🚴 Fitness support: work out on-site at our gym or explore the city using the Multisport Card, subsidised by SumUp for access to sports facilities across Warsaw  * 🩺 Commitment to well-being: access health insurance coverage for you and your family, plus life insurance to further protect your peace of mind  * 🏖️ Generous time off: enjoy 26 days of paid leave plus public holidays and special leave days * 🌴 Break4me: 1-month sabbatical after 3 years of service  * 🔗 Referral Bonus: earn additional rewards by referring talented individuals to join the SumUp team   *Disclaimer The stated salary range represents the expected compensation for candidates who meet the core requirements of this role. Offers above this range may be considered in exceptional circumstances, subject to internal review and approval, where a candidate's qualifications, skills, or experience significantly exceed the role's standard expectations. Job Application Tip We recognise that candidates feel they need to meet 100% of the job criteria in order to apply for a job. Please note that this is only a guide. If you don’t tick every box, it’s ok too because it means you have room to learn and develop your career at SumUp.

Senior Android Engineer - KMP

Sumup

Salary range: 18 850 - 29 660 PLN per month About the team SumUp’s Point-of-Sale (POS) solution empowers cafes, shops, bars, hair salons, and other businesses to operate efficiently and grow. It offers a wide range of features, including product catalogs, inventory management, business analytics, compliance support, and loyalty tools. Our POS solution integrates seamlessly into the SumUp SuperApp, which supports both our proprietary register hardware and mobile devices like tablets and phones. As a Senior Android Developer, you’ll collaborate with a dynamic, cross-functional team of Product Managers, Product Designers, Engineering Managers, and fellow engineers. About the role We’re evolving toward a Kotlin Multiplatform (KMP) strategy, enabling shared development across Android and iOS. In this role, you’ll learn, refine, and help implement this technology, shaping the future of our mobile apps. You’re a developer who values user-centric design, precision, and seamless collaboration. You bring structure to communication and thrive in a cross-functional environment.  This role will be a B2B based role in Warsaw. What you’ll do * Build new features for the item catalog within the SumUp SuperApp * Help improve the architecture of the application and contribute to our Kotlin Multiplatform strategy * Enhance and maintain our unified android app, distributed across 60+ countries, ensuring high-quality, scalable solutions * Shape the product’s evolution by identifying opportunities for improvement and contributing to daily decision-making * Write thorough documentation and implement robust testing for features before shipping * Collaborate closely with Designer, Product Manager and Android engineers to deliver a unified UX experience across platforms You’ll thrive in this role if: * You have 8+ years experience in mobile engineering with Android and Kotlin. * You have 2+ years of experience working with Jetpack Compose. * You have a solid understanding of software design patterns (e.g., MVVM, MVI) and expertise in building modular, scalable app architectures. * You have good knowledge of reactive programming (Flow, Coroutines and Concurrency). * You have a strong grasp of testing best practices: knowing what to test, why, and how to write resilient tests. * You strive for clean code, and you are flexible to balance pragmatism and perfection. * You have a keen interest in multi-platform development using Kotlin Multiplatform. WHY YOU SHOULD JOIN SUMUP (WARSAW) 🇵🇱 🌎 Opportunity to work , from our vibrant Warsaw office with inspiring art-filled lounges and a skyline terrace in the Mennica Legacy Tower.  🌈 Commitment to Diversity and Inclusion: be part of a workplace that values and promotes diversity, fostering an inclusive environment where everyone's perspectives are respected and embraced  🚀 Enrolment onto our VSOP program: you will own a stake in SumUp’s future success  🚴 Fitness support: work out on-site at our gym or explore the city using the Multisport Card, subsidised by SumUp for access to sports facilities across Warsaw  🩺 Commitment to well-being: access health insurance coverage for you and your family, plus life insurance to further protect your peace of mind  🏖️ Generous time off: enjoy 26 days of paid leave plus public holidays and special leave days 🌴 Break4me: 1-month sabbatical after 3 years of service  🔗 Referral Bonus: earn additional rewards by referring talented individuals to join the SumUp team *Disclaimer The stated salary range represents the expected compensation for candidates who meet the core requirements of this role. Offers above this range may be considered in exceptional circumstances, subject to internal review and approval, where a candidate's qualifications, skills, or experience significantly exceed the role's standard expectations.   Job Application Tip We recognise that candidates feel they need to meet 100% of the job criteria in order to apply for a job. Please note that this is only a guide. If you don’t tick every box, it’s ok too because it means you have room to learn and develop your career at SumUp.