Senior Software Engineer - Python

RTB House

Location: Poland (Remote/Flexible) We are:  RTB House is a global company that provides state-of-the-art marketing technologies for top brands and agencies worldwide. Its proprietary ad-buying engine is the first in the world to be powered entirely by Deep Learning algorithms, enabling advertisers to generate outstanding results and reach their goals at every stage of the funnel.  We are looking for engineers to join our Bidding Platform organization which is the core of the RTB business, processing over 20 million requests per second to participate in real-time auctions and display advertisements to customers from 90+ countries. If you want to work on technically complex and demanding solutions, this is the opportunity for you! Our Senior Engineers are experts who combine deep technical expertise with a strong sense of ownership, and they take on Tech Lead roles in complex, cross-team projects.  You will: * Gain deep understanding our ad technology and become familiar with ad industry standards: OpenRTB, MRAID, VAST etc. * Design and lead implementation of high-quality frontend solutions for displaying Ads globally, focusing on performance and scalability. * Write, test, and deploy robust, efficient, and well-documented code in JavaScript/TypeScript, ensuring adherence to the highest coding standards. * Develop monitoring systems to track crucial metrics like reliability or viewability and use data to diagnose and resolve performance bottlenecks. * Collaborate closely with Ads Layouts specialists and backend engineers to ensure smooth data flow and optimal architectural alignment for performance-critical features. * Provide hands-on technical leadership: solving complex system challenges, participating in planning and scoping of projects, and ensuring the implementation of the highest coding standards through participation in code reviews. Requirements: * 8+ years of hands-on experience in developing complex web software * Proficiency in JavaScript/TypeScript and browser APIs. Experience with relevant build tooling (e.g., Webpack, Vite). * Practical experience and strong understanding of Web Performance optimization techniques and advanced loading strategies (caching, asset delivery). * Very good knowledge of fundamental Internet protocols and technologies (DNS, HTTP, cookies and others). * Practical ability to observe, monitor and analyse the operation of production systems (and draw valuable conclusions from it). * Good understanding of full-stack concepts, including system architectures, working with backend APIs and deployment/CI/CD pipelines. * C1 level in English and Polish. Nice to have: * Experience in the AdTech/Real Time Bidding space. * Experience contributing to Real User Monitoring (RUM) 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. 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.

Fresha

The AI-powered OS for beauty, wellness and self-care About Fresha Fresha is the AI-powered operating system for the global beauty, wellness and self-care industry, connecting and powering everything from salons and barbers to spas, medspas, fitness studios and health practices. Trusted by millions of consumers and businesses worldwide. Fresha is used by 140,000+ businesses and 450,000+ stylists and professionals worldwide, processing over 1 billion appointments to date. The company is headquartered in London, United Kingdom, with 15 global offices located across North America, EMEA and APAC. Fresha allows consumers to discover, book and pay for beauty and wellness appointments with local businesses via its marketplace, while beauty and wellness businesses and professionals use an all-in-one platform to manage their entire operations with an intuitive business software and financial technology solutions.   Fresha’s ecosystem gives merchants everything they need to run their business seamlessly by facilitating appointment bookings, point-of-sale, customer records management, marketing automation, loyalty, beauty products inventory and team management.   The consumer marketplace unlocks revenue potential for partner businesses by leveraging the power of online bookings and automated marketing through mobile apps and advanced integrations with major tech brands including Instagram, Facebook and Google. Role overview Given our exciting and progressive growth plans, we are seeking an exceptional Senior IT Operations Engineer to join our global business.   Reporting directly to the IT Manager and working collaboratively with the Security and Compliance teams, you will be accountable for enabling our international workforce to do their jobs effectively through reliable IT infrastructure and support, ensuring compliance with company and security standards at Fresha.    This is a great opportunity for someone looking to work in a fast-paced and dynamic environment who enjoys working autonomously, likes to take on challenges, and wants to make a meaningful impact.   To foster a collaborative environment that thrives on face-to-face interactions and teamwork, this role will be based in our office 5 days per week in Warsaw - 20th Floor, Aleje Jerozolimskie 81, 02-001 Warsaw, Poland 

Avaron AB

About the Company At Avaron, you get the security of permanent employment combined with the variety of working at different customers. We place specialists across everything from tech, IT and industry to project management and business support – and whatever the assignment, you have a consultant manager who is there for you and your development. About the Role You will join a hands-on engineering role focused on making modern development smoother, faster and more reliable. The work centers on improving developer productivity through internal tooling, reusable automation and scalable CI/CD solutions, while also supporting Azure-based data platforms in a cross-functional environment. This role suits you if you enjoy building practical solutions that other engineers rely on every day. You will work close to engineering and platform teams, with plenty of room to influence how workflows, quality and traceability are improved across the broader technical landscape. It is a great opportunity if you want to combine software engineering, DevOps and data-platform work in a role where your solutions will have clear and visible impact. Job DescriptionYou will develop Python-based automation, internal tooling and engineering workflows for production-oriented use. You will build, maintain and improve GitHub Actions, GitHub Workflows and reusable CI/CD pipelines. You will support Azure-based data platforms, including Databricks and related technologies. You will help strengthen software quality, traceability and engineering processes across teams. You will collaborate with engineers and platform specialists to deliver scalable technical solutions. You will contribute in both Windows and Linux environments, with a focus on reliable delivery and efficient development flows. RequirementsStrong Python skills for production-oriented automation and tooling. Practical hands-on experience with Azure Databricks, ideally including development of notebooks, pipelines or jobs, or Spark-based solutions. Experience with Azure data-platform technologies such as Spark, Kafka, Hadoop, schema enforcement, data quality validation or Power BI. Hands-on experience with GitHub Actions, GitHub Workflows and reusable workflow design. Solid Docker experience. Experience working with CI/CD in Windows and Linux environments. Ability to work independently while collaborating across teams. EU citizenship. Nice to haveExperience with data governance and data modelling. Experience with machine learning model deployment. Experience with GitHub CLI, REST APIs or GraphQL APIs. Experience with JFrog Artifactory or similar tools. Experience with Bash and or PowerShell. Experience with Git LFS. Experience with GitHub Enterprise Server and self-hosted runners. Experience with AI-powered developer tools or agentic engineering workflows. What We OfferPermanent employment at Avaron AB Occupational pension Wellness allowance of SEK 5,000 per year Application Selections are made on an ongoing basis – apply as soon as you can.