Senior Software Engineer (Java/Kotlin)

About the job: Massive Scale: Design, build, and optimize high-throughput systems processing over 120 million daily offer events on one of Allegro’s largest distributed services.Applied AI Integration: Build backend services that leverage AI capabilities to automate workflows. You will integrate existing AI systems to generate content, classify offer attributes, and transform unstructured data to power automated decision-making.Strategic Business Impact: Design and evolve vertical product experiences using Domain-Driven Architecture in the Electronics domain, supporting Allegro's strategic shift toward a specialized, shop-in-shop ecosystem.Modern Tech Stack: Work primarily in Kotlin to build our backend services. While the backend is our core, having an interest in frontend technologies (like React, Angular, or Vue.js) is a great plus, as we value full-stack capabilities. Join the Enhance Category Experience team! You will build and scale vertical product experiences in the Electronics domain, driving Allegro’s strategic evolution into an ecosystem of specialized category zones. In this role, you will integrate AI capabilities to classify data, generate content, and ship features that directly impact millions of customers across Poland and international markets. High performance, engineering best practices, and a great team atmosphere guaranteed! Important things for you: Flexible working hours in the hybrid model (4/1) - working hours start between 7:00 a.m. and 10:00 a.m. We also have 30 days of occasional remote work.Depending on your annual assessment and the company's results we offer:PLN 18 850 - 25 900Annual bonus based on your annual performance and company results.Long term discretionary incentive plan based on Allegro.eu shares (restricted stock units).Our team is based in Kraków.We are looking for people who: Have commercial experience coding in Kotlin or Java (with an eagerness to master Kotlin for our new services);Possess solid commercial experience with the Spring Boot ecosystem to build scalable microservices and RESTful APIs;Value high-quality code and engineering best practices to solve complex challenges in massive-scale distributed systems;Are open-minded, adaptable, and eager to step outside your comfort zone to explore unfamiliar tech stacks (e.g., frontend is a nice-to-have) Are adept at utilizing AI-powered tools to accelerate coding, debugging, and research in your daily workflow;Communicate effectively in Polish and English (at least a B2 level). What's in it for you: Well-located offices (with e.g. fully equipped kitchens, bicycle parking, terraces full of greenery) and excellent work tools (e.g., raised desks, ergonomic chairs, interactive conference rooms).A 16' or 14' MacBook Pro or corresponding Dell with Windows (if you don't like Macs) and all the necessary accessories.A wide selection of fringe benefits in a cafeteria plan - you choose what you like (e.g., medical, sports or lunch packages, insurance, purchase vouchers).English classes that we pay for related to the specific nature of your job.A training budget, inter-team tourism (see more here), hackathons, and an internal learning platform where you will find multiple trainings.An additional day off for volunteering, which you can use alone, with a team, or with a larger group of people connected by a common goal.Social events for Allegro people - Spin Kilometers, Family Day, Fat Thursday, Advent of Code, and many other occasions we enjoy.And that's just the beginning! You can read more about the benefits here. #goodtobehere means that: You will join a team you can count on - we work with top-class specialists who have knowledge- and experience-sharing in their DNA.You will love our level of autonomy in team organization, the space for continuous development, and the opportunity to try new things. You get to choose which technology solves the problem and you are responsible for what you create.You will value our Developer Experience and the full platform of tools and technologies that make creating software easier. We rely on an internal ecosystem based on self-service and widely used tools such as Kubernetes, Docker, Consul, GitHub, and GitHub Actions. Thanks to this, you can contribute to Allegro from your very first days on the job.You will be equipped with modern AI tools to automate repetitive tasks, allowing you to focus on developing new services and refining existing ones (also leveraging AI support).You will create solutions that will be used (and loved!) by your friends, family and millions of our customers.You will meet the Allegro Scale, which starts with over 1000 microservices, an open-source data bus (Hermes) with 300K+ rps, a Service Mesh with 1M+ rps, tens of petabytes of data, and production-used machine learning.You will become part of Allegro Tech - we speak at industry conferences, cooperate with tech communities, run our own blog (it's been over 10 years!), record podcasts, lead guilds, and we organize our own internal conference - the Allegro Tech Meeting. We create solutions we love (and can) to talk about! Send us your CV and... see you at Allegro!