Backend Engineer Senior/Mid

🏢 Summary: Senior Backend Engineer role building and operating scalable core services and developer-facing tools for a voice platform. The position spans backend and frontend development, with end-to-end ownership of distributed, cloud-native production systems and collaboration with ML teams. 🗂️ Requirements: 6+ years building and operating distributed backend services, Professional Java experience, Experience designing gRPC/HTTP APIs, Experience with distributed systems and event-driven architectures, Experience operating cloud-native infrastructure in production, End-to-end production system ownership, Ability to collaborate with ML and cross-functional teams, Clear communication of technical trade-offs 📃 Skills: Java, Python, gRPC, HTTP, APIs, Cloud-native, Distributed, Event-driven 🏢 Description: We are looking for a Senior backend Engineer to help build the core services and user-facing tools that power a voice platform. In this role, you will develop and operate the platform's foundational backend systems while also building intuitive frontend experiences. You will work across the full stack, designing scalable backend services and creating high-quality frontend applications that enable internal teams and partners to build, test, and manage voice experiences. This is an opportunity to work on distributed systems at scale, shape developer-facing tools, and own features from concept through production. What You'll Do Design, build, and operate scalable backend services. Develop and maintain distributed systems using gRPC/HTTP APIs and event-driven architectures. Build cloud-native services with a strong focus on reliability, scalability, and performance. Own production systems end-to-end, including architecture, implementation, deployment, monitoring, and iteration. Partner closely with ML engineers to design robust interfaces between backend services and model-serving infrastructure. Collaborate with engineers and cross-functional stakeholders to deliver high-quality technical solutions. Champion engineering best practices, operational excellence, and maintainable system design. Who You Are You have 6+ years of experience building and operating distributed backend services. You have strong professional experience with Java and Python. Experience with Java is essential, while Python is a plus because much of the team's tooling is built in it. You have experience designing and developing gRPC/HTTP APIs, distributed systems, and event-driven architectures. You have experience building and operating cloud-native infrastructure in production environments. You take ownership of systems throughout their full lifecycle, from design through production support. You collaborate effectively with machine learning teams and cross-functional partners. You are an excellent communicator who can clearly explain technical trade-offs to both technical and non-technical stakeholders.

🏢 Summary: Backend Engineer role focused on building and operating the AI inference and orchestration systems behind a production AI assistant. The position emphasizes low-latency, high-throughput APIs, distributed-system reliability, observability and performance optimization for mobile, desktop and machine-learning integrations. Remote-first collaboration is available for a candidate working from Poland, with base salary and equity assessed individually. 🗂️ Requirements: Production backend engineering experience, High-throughput, low-latency service experience, AI inference familiarity: LLMs, embeddings, multimodal models, Distributed-systems debugging under load, Production observability and incident-management knowledge, Performance-optimization expertise, Independent delivery in ambiguous environments, Working from Poland, Working-hours overlap with immediate team 📃 Skills: Python, Node.js, PyTorch, OpenAI, Anthropic, LLMs, Embeddings, SQL, NoSQL, Kubernetes, Docker, APIs, Caching, Batching, Streaming, Logging, Alerting 🏢 Description: About the product Our client is developing an AI-native assistant designed to support everyday communication, organization, errands and complex workflows with minimal user input. The product must reliably manage long-running processes, retain context, interact with external tools and complete real-world tasks despite the non-deterministic nature of modern AI models. The company’s objective is to make everyday activities significantly faster and easier for users. About the role As a Backend Engineer specializing in AI systems, you will own the inference and orchestration layer behind the product’s AI interactions. Your work will sit between models and end users, where latency, correctness, reliability and operating costs directly affect the product experience. You will build and operate production systems that transform model capabilities into fast, stable and observable APIs used by mobile and desktop applications. What you will do Build and operate backend systems serving AI-powered functionality in production. Design inference pipelines, orchestration layers and service boundaries around Machine Learning models. Take ownership of production monitoring, logging, alerting and incident response. Optimize latency and throughput across inference, caching, batching and streaming. Build reliable APIs supporting integration with mobile, frontend and Machine Learning systems. Diagnose distributed-system issues under production load. Continuously improve system performance and reliability using real-world production signals. What we are looking for Strong backend engineering fundamentals supported by experience with production systems. Experience building or operating high-throughput, low-latency services. Familiarity with AI inference patterns, including LLMs, embeddings and multimodal models. Confidence debugging distributed systems under load. Understanding of production observability, incident management and performance optimization. A delivery-oriented mindset focused on shipping, observing production behavior and improving through iteration. Ability to work independently and make pragmatic engineering decisions in an ambiguous environment. What success looks like Backend systems reliably handle production AI traffic at scale with low latency and high throughput. APIs remain stable, clear and easy to integrate with frontend, mobile and Machine Learning systems. Production incidents are detected quickly, diagnosed effectively and resolved with minimal impact on users. System performance and reliability improve continuously based on real-world usage and production data. Technology stack Python Node.js PyTorch OpenAI, Anthropic and open-source LLMs SQL and NoSQL databases Kubernetes Docker Compensation and employment The position is offered under an employment contract. The company does not publish a fixed external salary range. Compensation is assessed individually based on: professional experience and technical capability, scope of responsibility, location and relevant market benchmarks, expected impact on the product and organization. Candidates may share their expected compensation at the beginning of the recruitment process. The compensation package consists of a base salary and equity, with flexibility for exceptional candidates. A company laptop will be provided where required for the role. Remote work and global collaboration The company operates as a remote-first, globally distributed organization. There is no fixed company-wide working schedule and no requirement to follow one specific time zone. Team members are expected to maintain sufficient working-hours overlap with their immediate colleagues to collaborate effectively. The successful candidate will work from Poland and collaborate with backend, Machine Learning, mobile and product specialists located across different regions. Poland-based employees join existing global teams rather than a separate local team. The exact reporting line and hiring manager will be confirmed during the recruitment process. How the team works The company believes that outstanding products are built by small, highly capable and hands-on teams. Decisions are made collaboratively, while individuals are expected to take ownership, bring structure to ambiguous problems and execute independently. The team moves quickly while balancing production quality, experimentation and continuous learning from real user behavior. There is no fixed hiring quota for this position. The company is focused on identifying engineers who meet its technical and ownership standards rather than filling a predetermined number of seats. Recruitment process The standard recruitment process consists of up to four stages: Technical assessment, where relevant to the candidate’s background. HR interview. One or more technical interviews. Founder or leadership interview. Particularly strong candidates may be fast-tracked directly to the technical interview stage based on their experience and previous work. Applications are evaluated by members of the technical team. Interviews may be conducted virtually and, where relevant, onsite. The exact format and interviewers may vary. The company aims to make decisions efficiently and provide candidates with a prompt outcome.

🏢 Summary: Senior AI Applied Software Engineer role focused on building secure, scalable digital-banking entitlement services and end-to-end product features. The position combines Java/Spring microservices and Angular frontend development with AI initiatives such as LLM voice assistants and real-time personalization, in a hybrid Kraków setup. 🗂️ Requirements: Kraków-area residence, Hybrid office work twice weekly, 5+ years of experience, Java, Spring, JPA/Hibernate, Maven, Microservices, Cloud, Angular, TypeScript, RxJS, Webpack, Jenkins, Enterprise Integration Patterns, CI/CD, English 📃 Skills: Java, Spring, JPA, Hibernate, Maven, Microservices, Cloud, Angular, TypeScript, RxJS, Webpack, Jenkins, OpenAI, ML, Vue.js, NetflixOSS 🏢 Description: The Job At Backbase, we don’t just deliver software – we redefine how people manage their finances. We are looking for a Senior AI Applied Software Engineer to join our R&D department in Kraków. You will join the team which sits at the core of Backbase platform: Entitlements. Handling complex problems related to Access Control, Approvals and Limits. By joining our team, you won’t just write code; you will design systems that impact millions of users across over 100 financial institutions worldwide. Meet the Job As a Senior AI Applied Software Engineer  you are a technical cornerstone of your squad. You will design and deliver complex features with minimal guidance, ensuring that both the "engine" (Backend) and the "experience" (Frontend) are performant, secure, and scalable. Full SDLC Ownership: Lead the entire lifecycle of digital banking products—from initial idea and architectural design to release and maintenance. Architectural Excellence: Improve system architecture and design components that integrate smoothly across APIs and microservices. Technical Leadership: Act as a go-to resource for your team, mentoring junior engineers, conducting critical code reviews, and raising the bar for engineering standards. AI & Innovation: Contribute to the evolution of LLM-based voice assistants and real-time personalization engines using OpenAI and ML models. Security-First Mindset: Implement "Entitlements" and fraud prevention services with a focus on non-functional requirements like security, scalability, and resilience. Collaborative Culture: Work in a Pod based model, collaborating with Architects, Product Owners, and UX Designers to align technical solutions with business needs. Who You Are Location: You live in Kraków or nearby area and you are willing to work in a hybrid mode - twice per week from our office. Experience: You have 5–7+ years of professional experience building complex, high-traffic products. Backend Mastery: Solid understanding of Java , Spring JPA/Hibernate , and Maven . Experience with Microservices (Netflix OSS is a plus) and Cloud technologies. Frontend Expertise: Strong skills in Angular and TypeScript . You are proficient with RxJS and modern build systems (Webpack, Jenkins). Experience with Vue.js is a plus. System Design: You have a solid grasp of Enterprise Integration Patterns and can design systems that handle complex data flows between services. The "Senior" Edge: You don't just solve tickets; you identify gaps in tooling, reduce technical debt, and optimize CI/CD pipelines to streamline delivery. Communication: Excellent English (spoken and written). You can confidently explain technical concepts to non-technical stakeholders and get buy-in for your architectural decisions. Domain Knowledge: Previous experience in Fintech or Banking is highly considered an advantage. What We Offer Growth: €1,000 annual self-development budget, a clear promotion path, and dedicated time for training. Rewards: Competitive base salary plus an annual bonus and referral bonuses. Hybrid Work: A flexible arrangement combining remote work with our vibrant Kraków office. Office Perks: Daily lunches, community breakfasts on Wednesdays, and high-end hardware (MacBook). Well-being: Private healthcare (Luxmed), Headspace app subscription, and a Work-From-Home allowance. Culture: Integration events, flexible working hours, and a focus on healthy work-life balance.

🏢 Summary: Senior AI Applied Software Engineer role focused on building secure, scalable digital banking onboarding and product-management experiences. The position owns end-to-end delivery of backend-centric features, contributes to AI-powered assistants and personalization, and provides technical leadership within a cross-functional squad. Hybrid work from the Kraków office is required twice per week. 🗂️ Requirements: Live in or near Kraków, Work hybrid from the office twice weekly, 5–7+ years of experience building complex, high-traffic products, Java, Spring JPA/Hibernate, Maven, Microservices, Cloud technologies, Enterprise Integration Patterns, CI/CD optimization, Excellent written and spoken English, System design for complex inter-service data flows 📃 Skills: Java, Spring, JPA, Hibernate, Maven, Microservices, Cloud, CI/CD, OpenAI, ML, APIs 🏢 Description: The Job At Backbase, we don’t just deliver software – we redefine how people manage their finances. We are looking for a Senior AI Applied Software Engineer to join the Onboarding & Origination value stream within the R&D department. You will focus on creating innovative, efficient, and adaptive solutions that streamline operations, enhance compliance, and drive superior performance for financial institutions. You will be working on building the customer experience path of exploring banking products and banking products management. By joining our team, you won’t just write code; you will design systems that impact millions of users across over 100 financial institutions worldwide. Meet the Job As a Senior AI Applied Software Engineer you are a technical cornerstone of your squad. You will design and deliver complex features with minimal guidance, ensuring that both the "engine" (Backend) and the "experience" (Frontend) are performant, secure, and scalable. Full SDLC Ownership: Lead the entire lifecycle of digital banking products—from initial idea and architectural design to release and maintenance. Architectural Excellence: Improve system architecture and design components that integrate smoothly across APIs and microservices. Technical Leadership: Act as a go-to resource for your team, mentoring junior engineers, conducting critical code reviews, and raising the bar for engineering standards. AI & Innovation: Contribute to the evolution of LLM-based voice assistants and real-time personalization engines using OpenAI and ML models. Security-First Mindset: Implement services with a focus on non-functional requirements like security, scalability, and resilience. Collaborative Culture: Work in a Pod based model, collaborating with Architects, Product Owners, and UX Designers to align technical solutions with business needs. Who You Are Location: You live in Kraków or nearby area and you are willing to work in a hybrid mode - twice per week from our office. Experience: You have 5–7+ years of professional experience building complex, high-traffic products. Backend Mastery: Solid understanding of Java , Spring JPA/Hibernate , and Maven . Experience with Microservices (Netflix OSS is a plus) and Cloud technologies. Frontend Exposure: While the daily work is heavily backend-centric, prior exposure to Angular/TypeScript (RxJS) or Vue.js is a welcome bonus, offering a great foundation for future fullstack growth within the team. System Design: You have a solid grasp of Enterprise Integration Patterns and can design systems that handle complex data flows between services. The "Senior" Edge: You don't just solve tickets; you identify gaps in tooling, reduce technical debt, and optimize CI/CD pipelines to streamline delivery. Communication: Excellent English (spoken and written). You can confidently explain technical concepts to non-technical stakeholders and get buy-in for your architectural decisions. Domain Knowledge: Previous experience in Fintech or Banking is highly considered an advantage. What We Offer Growth: €1,000 annual self-development budget, a clear promotion path, and dedicated time for training. Rewards: Competitive base salary plus an annual bonus and referral bonuses. Hybrid Work: A flexible arrangement combining remote work with our vibrant Kraków office. Office Perks: Daily lunches, community breakfasts on Wednesdays, and high-end hardware (MacBook). Well-being: Private healthcare (Luxmed), Headspace app subscription, and a Work-From-Home allowance. Culture: Integration events, flexible working hours, and a focus on healthy work-life balance.

🏢 Summary: Senior AI Applied Software Engineer role focused on building secure, scalable digital banking products within the Entitlements domain. The position leads end-to-end delivery of frontend-centric features, system architecture, and AI-driven capabilities while collaborating in a hybrid Kraków-based team. 🗂️ Requirements: Kraków-area residence and hybrid office availability twice weekly, 5–7+ years building complex, high-traffic products, Angular proficiency, TypeScript proficiency, RxJS proficiency, Modern build-system experience, Enterprise Integration Patterns knowledge, Complex data-flow system design experience, CI/CD pipeline optimization experience, Excellent spoken and written English 📃 Skills: Angular, TypeScript, RxJS, Webpack, Jenkins, Java, Spring, JPA, Hibernate, Maven, Microservices, NetflixOSS, Cloud, OpenAI, LLMs, ML, Vue.js 🏢 Description: The Job At Backbase, we don’t just deliver software – we redefine how people manage their finances. We are looking for a Senior AI Applied Software Engineer to join our R&D department in Kraków. You will join the team which sits at the core of Backbase platform: Entitlements. Handling complex problems related to Access Control, Approvals and Limits. By joining our team, you won’t just write code; you will design systems that impact millions of users across over 100 financial institutions worldwide. Meet the Job As a Senior AI Applied Software Engineer  you are a technical cornerstone of your squad. You will design and deliver complex features with minimal guidance, ensuring that both the "engine" (Backend) and the "experience" (Frontend) are performant, secure, and scalable. Full SDLC Ownership: Lead the entire lifecycle of digital banking products—from initial idea and architectural design to release and maintenance. Architectural Excellence: Improve system architecture and design components that integrate smoothly across APIs and microservices. Technical Leadership: Act as a go-to resource for your team, mentoring junior engineers, conducting critical code reviews, and raising the bar for engineering standards. AI & Innovation: Contribute to the evolution of LLM-based voice assistants and real-time personalization engines using OpenAI and ML models. Security-First Mindset: Implement "Entitlements" and fraud prevention services with a focus on non-functional requirements like security, scalability, and resilience. Collaborative Culture: Work in a Pod based model, collaborating with Architects, Product Owners, and UX Designers to align technical solutions with business needs. Who You Are Location: You live in Kraków or nearby area and you are willing to work in a hybrid mode - twice per week from our office. Experience: You have 5–7+ years of professional experience building complex, high-traffic products. Frontend Mastery: Strong skills in Angular and TypeScript . You are proficient with RxJS and modern build systems (Webpack, Jenkins). Experience with Vue.js is a plus. Backend Exposure: While the daily work is heavily frontend-centric, prior exposure to of Java , Spring JPA/Hibernate , Maven, Microservices (Netflix OSS is a plus) and Cloud technologies is a welcome bonus, offering a great foundation for future fullstack growth within the team. System Design: You have a solid grasp of Enterprise Integration Patterns and can design systems that handle complex data flows between services. The "Senior" Edge: You don't just solve tickets; you identify gaps in tooling, reduce technical debt, and optimize CI/CD pipelines to streamline delivery. Communication: Excellent English (spoken and written). You can confidently explain technical concepts to non-technical stakeholders and get buy-in for your architectural decisions. Domain Knowledge: Previous experience in Fintech or Banking is highly considered an advantage. What We Offer Growth: €1,000 annual self-development budget, a clear promotion path, and dedicated time for training. Rewards: Competitive base salary plus an annual bonus and referral bonuses. Hybrid Work: A flexible arrangement combining remote work with our vibrant Kraków office. Office Perks: Daily lunches, community breakfasts on Wednesdays, and high-end hardware (MacBook). Well-being: Private healthcare (Luxmed), Headspace app subscription, and a Work-From-Home allowance. • • Culture: Integration events, flexible working hours, and a focus on healthy work-life balance.

🏢 Summary: Senior Backend Software Engineer role focused on designing, building, and operating secure, scalable .NET microservices for cloud and hybrid environments. The position delivers backend features end to end using Azure services, SQL Server, Cosmos DB, asynchronous messaging, automated testing, and CI/CD practices. 🗂️ Requirements: 5+ years of backend or distributed systems engineering experience, Proficiency in C#, .NET 8/10, ASP.NET Core, and Azure Functions, Experience with SQL Server, T-SQL, EF Core, RLS, and NoSQL databases, Practical Azure services experience, Knowledge of OAuth2, JWT, and identity-provider integrations, Experience with multi-tenant SaaS architectures, Knowledge of asynchronous message-driven systems, Experience with CI/CD, Terraform, and Docker/Kubernetes, Strong unit and integration testing practices 📃 Skills: C#, .NET, ASP.NET, Azure, SQL, T-SQL, EF, CosmosDB, OAuth2, JWT, SaaS, CI/CD, Terraform, Docker, Kubernetes, xUnit, Moq, FluentAssertions, GitHub, Azurite 🏢 Description: We are looking for an experienced Senior Backend Software Engineer to design, build, and operate backend services within a modern, scalable microservices environment. The role involves working with ASP .NET Core, Azure Functions, SQL Server, and Azure CosmosDB to deliver high‑performance, secure solutions for cloud and hybrid environments. Key Responsibilities: ·       End‑to‑end development of backend features using ASP .NET Core APIs, Azure Functions, SQL Server, and CosmosDB ·       Building and extending .NET services in a microservices architecture ·       Implementing resilient, asynchronous workflows using Azure Service Bus ·       Designing secure and efficient data access patterns (SQL Server, CosmosDB) ·       Ensuring multi‑tenant data isolation and compliance with security standards ·       Using Azure services such as Service Bus, Blob Storage, App Configuration, Application Insights, and Entra ID ·       Writing unit and integration tests (xUnit, Moq, FluentAssertions) ·       Contributing to CI/CD pipelines (GitHub Actions, Azure DevOps) ·       Working with Terraform, Docker Compose, and Azurite ·       Identifying and resolving performance, security, and reliability issues ·       Independently delivering backend features from design to production ·       Participating in architecture discussions and code reviews ·       Collaborating with product and frontend teams on API design ·       Mentoring junior engineers and promoting AI‑driven development practices. Qualifications: ·       Minimum 5  years of experience in backend or distributed systems engineering ·       Strong proficiency in C# / .NET 8/10, ASP .NET Core, Azure Functions ·       Experience with SQL Server (T‑SQL, EF Core, RLS) and NoSQL databases (CosmosDB preferred) ·       Practical knowledge of Azure services (Functions, Service Bus, Blob Storage, App Configuration, App Insights) ·       Understanding of OAuth2, JWT, and identity provider integrations ·       Experience with multi‑tenant SaaS architectures ·       Familiarity with asynchronous, message‑driven systems ·       Knowledge of CI/CD, Terraform, Docker/Kubernetes ·       Strong testing discipline and communication skills. Benefits: ·       Health benefits & insurance ·       Multisport card ·       Learning and development opportunities ·       Flexible work schedule ·       Innovative work in cybersecurity and AI-native environment ·       Opportunities for career growth. Apply now!