Ruby Developer

🏢 Summary: Backend Engineer role focused on designing and scaling real-time, cloud-based systems and APIs for an AI-powered consumer product. The position involves building reliable backend services, data pipelines, and infrastructure on AWS within a high-performing engineering team. You will collaborate with mobile and AI teams to deliver low-latency, scalable, and secure user experiences. 🗂️ Requirements: 2+ years backend development experience with Node.js and TypeScript, Strong knowledge of PostgreSQL including schema design and query optimization, Experience with Redis for caching and queue management, Hands-on experience with AWS services (EC2, RDS, Lambda, ECS, S3), Strong REST API design skills and real-time communication patterns, Understanding of scalability, concurrency, and distributed systems, Experience with Docker, Git workflows, and CI/CD automation, Knowledge of backend security and performance best practices 📃 Skills: Node.js, TypeScript, PostgreSQL, Redis, AWS, EC2, RDS, Lambda, ECS, S3, REST, WebSockets, SSE, Docker, Git, CICD 🏢 Description: Backend Engineer – Node.js, TypeScript, AWS For our client, a fast-growing team building a next-generation AI-powered consumer product, we are looking for an experienced Backend Engineer to help scale the systems powering real-time experiences, cloud synchronization, and intelligent APIs. This is not a founding role, but it is a highly impactful engineering position within a small, high-performing team focused on building world-class consumer technology products. About the role You will be responsible for designing, building, and scaling backend systems that support core product functionality — from real-time data pipelines to reliable cloud infrastructure and low-latency APIs. You’ll work closely with mobile and AI teams to deliver fast, scalable, and highly reliable user experiences. Responsibilities Backend Development Design and build RESTful APIs using Node.js and TypeScript (Express.js or Nest.js) Architect and maintain PostgreSQL databases, including schema design and query optimization Implement background jobs and queue systems using Redis for ingestion, summarization, and notifications Build and maintain caching layers (Redis, CDN, HTTP cache) to ensure low-latency performance Implement authentication, authorization, and data privacy best practices Add real-time capabilities using WebSockets and Server-Sent Events Build observability into services through logging, metrics, and tracing Deploy and manage backend services on AWS (EC2, ECS, RDS, S3, Lambda) Systems & Architecture Design clean, scalable, and maintainable service architectures Plan and execute safe database migrations and schema evolution strategies Ensure consistency and reliability across distributed systems Optimize system performance across I/O, CPU, and memory bottlenecks Build and maintain CI/CD pipelines and release automation workflows Contribute to infrastructure reliability, scalability, monitoring, and cost optimization Quality & Security Write unit, integration, and contract tests with clear quality standards Enforce linting, type safety, and static analysis within CI pipelines Conduct security reviews and dependency audits while following least-privilege principles Clearly document services, APIs, and important architectural trade-offs Requirements Must-have 2+ years of backend development experience with Node.js and TypeScript Strong understanding of PostgreSQL, including schema design, indexing, and query optimization Experience working with Redis for caching and queue management Hands-on experience with AWS services such as EC2, RDS, Lambda, ECS, and S3 Strong API design skills, including REST and real-time communication patterns Solid understanding of scalability, concurrency, and distributed systems Experience with Docker, Git workflows, and CI/CD automation Familiarity with security and backend performance best practices Nice to have Experience with GraphQL or gRPC Exposure to event-driven architectures or microservices Familiarity with observability tools such as OpenTelemetry, CloudWatch, or Sentry Experience building high-traffic consumer applications Example stack Backend: Node.js, TypeScript (Express.js / Nest.js), PostgreSQL, Redis Cloud: AWS (EC2, RDS, Lambda, ECS, S3, CloudWatch) Infrastructure: Docker, GitHub Actions, CI/CD

🏢 Summary: Senior role focused on developing and maintaining a business applications ecosystem (CRM, document workflows, ERP and AI integrations) using Ruby on Rails. The position involves building integrations, processing documents, handling background jobs and realtime features, and deploying to self-managed Linux VPS infrastructure. It requires working on production systems and solving complex backend and integration challenges. 🗂️ Requirements: Very good knowledge of Ruby on Rails, Strong understanding of backend application architecture, Strong knowledge of SQL and relational databases, Experience with integrations and API design/debugging, Experience with background jobs and asynchronous processing, Ability to work with Linux/VPS environments 📃 Skills: Ruby, Rails, ActiveRecord, ActiveJob, SolidQueue, ActionCable, ActionMailer, ActionMailbox, MySQL, MSSQL, TinyTds, SQL, REST, KSeF, Claude, IMAP, Backblaze, Linux, Ubuntu, Puma, systemctl, crontab, logrotate, Tailscale, CombinePDF, Node.js, ERP, VPS 🏢 Description: Senior Ruby on Rails Backend Engineer Szukamy doświadczonego Ruby on Rails Backend Developera do rozwijania naszego ekosystemu aplikacji biznesowych (CRM, obieg dokumentów, workflow, integracje ERP, KSeF, automatyzacje procesów). Projekt obejmuje: integracje z systemami zewnętrznymi, przetwarzanie dokumentów, background jobs, kolejki, realtime events, deployment na własnej infrastrukturze VPS, integracje AI i ERP. To rola dla osoby, która dobrze odnajduje się w systemach produkcyjnych i lubi rozwiązywać realne problemy biznesowe. Idealnie, jeśli jesteś z okolic Trzebini / Chrzanowa — preferujemy osoby, z którymi możliwa będzie okazjonalna współpraca stacjonarna przy planowaniu i wdrożeniach. Stack technologiczny Backend / Rails Ruby on Rails 7.2 Active Record Active Job + Solid Queue Action Mailer Action Cable Action Mailbox Bazy danych MySQL MS SQL Server (TinyTds) migracje Rails indeksy JSON columns Integracje KSeF REST API Claude API (Anthropic) IMAP polling Backblaze B2 TinyTds / Optima ERP Deployment / infrastruktura Linux VPS (Ubuntu) Puma systemctl crontab logrotate Tailscale VPN Dokumenty / PDF CombinePDF generowanie i stemplowanie PDF Node.js CLI wrappers Szukamy osoby, która: ma bardzo dobrą znajomość Ruby on Rails, rozumie architekturę aplikacji backendowych, dobrze zna SQL i relacyjne bazy danych, potrafi projektować i debugować integracje, ma doświadczenie z background jobs i async processing, swobodnie pracuje na Linux/VPS. Mile widziane doświadczenie z KSeF, doświadczenie z ERP, znajomość MSSQL, doświadczenie z realtime systems, integracje AI, doświadczenie z dużymi workflow dokumentowymi. Oferujemy realny wpływ na architekturę systemów, dużą samodzielność, brak korporacyjnych procesów, ciekawe integracje i problemy techniczne, możliwość długoterminowej współpracy. Forma współpracy B2B lub FV full-time lub part-time zdalnie / hybrydowo

🏢 Summary: Entry-level Backend Engineer role focused on supporting the development of backend services and REST APIs under senior guidance. The position involves contributing to production systems, writing tested and maintainable code, and collaborating within a cross-functional engineering team. Ideal for candidates with foundational Java experience seeking hands-on experience in scalable and secure systems. 🗂️ Requirements: Bachelor's degree in Computer Science or related field (or currently pursuing), Minimum 0.5 years of Java experience, Practical experience with RESTful APIs, Ability to work with HTTP methods, status codes, and JSON, Experience writing SQL queries (SELECT, JOIN, WHERE, GROUP BY) or using ORM, Basic understanding of SQL and NoSQL differences, Knowledge of data structures and algorithms, Ability to use Git in a team environment (branching, pull requests, merge conflicts), Experience writing unit tests, Experience contributing code to production through review and deployment process 📃 Skills: Java, REST, HTTP, JSON, SQL, NoSQL, ORM, Git, JUnit, Pytest, Jest, CI, Algorithms, DataStructures, APIs, Testing 🏢 Description: (5190) About This Role You will be a part of the Engineering team and reports to our Manager, Engineering. You will support the development of backend services and APIs that power customer’s products. Working under close guidance from experienced engineers, you will gain hands-on experience contributing to real-world systems while learning best practices in software development, scalability, and security. Key Responsibilities Support the development of backend services and APIs under direct supervision of senior engineers Assist with writing clean, maintainable, and well-documented code following team standards Help debug, test, and troubleshoot backend systems and services Contribute to small tasks or components within larger projects Collaborate with cross-functional teams including Frontend, Product, and DevOps Participate in code reviews and apply feedback to improve technical skills Assist in writing unit tests and validating functionality Document technical processes and development work Required Qualifications Bachelor's degree in Computer Science or a related field; Currently pursuing is also an option Strong theoretical knowledge of Java, at least 0.5 years of experience Practical experience building and consuming RESTful APIs — HTTP methods, status codes, JSON, request/response handling, basic error handling. Working knowledge of databases — has written real SQL queries (SELECT, JOIN, WHERE, GROUP BY) or used an ORM in production code; understands the difference between SQL and NoSQL at a basic level. Solid understanding of data structures and algorithms — arrays, hash maps, trees, basic Big-O analysis — sufficient to discuss simple coding problems and reason about correctness. Comfortable with Git in a team setting — branching, pull requests, code review, addressing feedback, resolving merge conflicts; has worked in a shared repository with at least one other developer. Hands-on experience writing unit tests for their own code (pytest, JUnit, Jest, or equivalent), and basic familiarity with how testing fits into a CI pipeline. Demonstrated ability to ship code to production — even small features or bug fixes — through a real review and deployment process; ability to clearly describe what they built, how it was reviewed, and how it was tested. Genuine interest in cryptocurrency, blockchain, or Web3 (self-taught is fine — owning crypto, reading, side projects, hackathons) and willingness to learn the regulated FinTech context; English level: Upper-intermediate or higher, sufficient for daily team communication and code review discussions. Bonus: exposure to Linux / command line, Docker basics, message queues (Kafka, RabbitMQ), cloud platforms (AWS, GCP), open-source contributions, hackathon participation, or an active public GitHub portfolio.

🏢 Summary: Senior Back-End Developer role focused on designing and building scalable, secure APIs and services for a SaaS legal-tech platform hosted on AWS. The position involves developing distributed systems, optimizing data models, and integrating multiple AWS services to support complex enterprise workflows. You will collaborate with cross-functional teams to improve performance, reliability, and architecture of the back-end systems. 🗂️ Requirements: Experience as Back-End or Full-Stack Developer in SaaS environment, Strong knowledge of Python 3.10+, Strong knowledge of Django 4.x and Django REST Framework, Experience with PostgreSQL, Experience with Redis and/or Elasticsearch/OpenSearch, Experience with Celery and asynchronous task processing, Familiarity with AWS services: ECS, Lambda, S3, RDS, SQS/SNS, Experience with Git and CI/CD pipelines, Experience working in Agile/Scrum environment, Strong debugging and performance optimization skills 📃 Skills: Python, Django, DjangoRESTFramework, PostgreSQL, Redis, Elasticsearch, OpenSearch, Celery, AWS, ECS, Lambda, S3, RDS, SQS, SNS, Git, CI/CD, Terraform, Terragrunt, pytest, Ruff 🏢 Description: About Us We build B2B legal technology that helps law firms and fund managers work faster and produce high-quality results. Our product helps manage the legal processes used when raising private investment funds. It makes drafting, negotiation, and compliance work easier and faster for lawyers. We use a single-tenant SaaS system hosted on AWS in several regions. Our technology stack includes Python/Django 4.2, React 18 with TypeScript, PostgreSQL, Redis, Elasticsearch/OpenSearch, S3, ECS, and Lambda. Role Overview We are looking for a Senior Back-End Developer to design, build, and improve the APIs, data models, and services behind our product. You will work closely with front-end developers, QA engineers, and DevOps specialists to create reliable, scalable, and secure back-end systems used by global business clients. The ideal candidate has strong experience with Python/Django, AWS services, and distributed systems. They care about performance, clean architecture, and maintainable code. Key Responsibilities Design and build RESTful APIs using Python 3.10+ and Django 4.x / Django REST Framework. Create scalable data models and efficient queries using PostgreSQL, Redis, and Elasticsearch/OpenSearch. Build background jobs and asynchronous tasks using Celery, SQS, and Lambda. Integrate AWS services such as S3, SNS/SQS, CloudFront, ECS, and RDS into application workflows. Take part in code reviews and maintain clean, secure, and well-documented services. Work with DevOps to improve CI/CD pipelines and infrastructure automation. Help plan system architecture, scalability, and performance improvements. Essential Requirements Experience working as a Back-End or Full-Stack Developer in a SaaS environment. Strong knowledge of Python 3.10+ and Django 4.x / Django REST Framework. Experience with PostgreSQL, Redis, and/or Elasticsearch/OpenSearch. Familiarity with Celery, SQS/SNS, and AWS services such as ECS, Lambda, S3, and RDS. Experience with Git, CI/CD processes, and Agile/Scrum development. Strong debugging and problem-solving skills with attention to performance and reliability. Preferred Requirements Experience with infrastructure-as-code tools such as Terraform or Terragrunt and AWS developer tools. Knowledge of authentication systems, role-based access control, and single-tenant architecture. Experience working with text or document processing libraries. Familiarity with testing and code quality tools such as pytest, Ruff, and pre-commit workflows. Personal Attributes Practical engineer who values reliability and clean system design. Analytical and detail-focused problem solver. Comfortable working and communicating in cross-functional Agile teams. Proactive in improving code quality and developer experience. What We Offer Competitive salary and benefits. Remote-first work culture with colleagues from different countries. Opportunity to shape the back-end architecture and services of our global legal-tech product. Experience working with complex enterprise workflows and automation challenges.

🏢 Summary: Backend Engineer role focused on designing, building, and maintaining scalable backend services in a cloud-native AWS environment. The position involves developing production-grade APIs and services using TypeScript and .NET, with strong emphasis on CI/CD, Infrastructure as Code, and cloud-native best practices. The role supports secure, scalable backend systems with close collaboration across platform and operations teams. 🗂️ Requirements: Strong experience building and maintaining scalable APIs and backend services, Hands-on experience with CI/CD pipelines using GitHub Actions or GitHub Workflows, Strong development experience with TypeScript, Strong development experience with .NET (C#), Experience deploying and operating workloads in AWS Cloud, Experience using Terraform for Infrastructure as Code, Experience designing and consuming RESTful APIs or event-driven services, Understanding of cloud-native patterns, Experience with relational databases and SQL, Fluent English 📃 Skills: TypeScript, .NET, C#, AWS, Terraform, SQL, REST, CI/CD, GitHub, GitHubActions, APIs, IAM, Lambda, ECS, Fargate 🏢 Description: We are looking for a Backend Engineer to design, build, and maintain backend services in a modern cloud-native AWS environment. Core skills & experience: Strong experience as a Backend Developer, building and maintaining scalable APIs and backend services Hands-on experience with CI/CD pipelines, preferably using GitHub Actions / GitHub Workflows Strong development experience with TypeScript and .NET (C#), including building and operating production services Familiarity with AWS Cloud, including deploying and operating backend workloads in AWS Experience using Terraform for Infrastructure as Code (IaC) Related technologies / domain knowledge: Experience designing and consuming RESTful APIs and/or event-driven backend services Understanding of cloud-native patterns (stateless services, scaling, resiliency, observability) Experience working with relational databases (SQL) and backend integrations Nice-to-have / preferred experience: Experience with containerized workloads (e.g. ECS Fargate or similar) Experience with Lambda functions Familiarity with IAM and AWS security best practices Exposure to data platforms or ETL-heavy environments Experience working in environments with high operational and security requirements General expectations: Able to take ownership of backend services from development through production Comfortable working closely with platform, data, and operations engineers Focused on clean code, automation, and reliable delivery through CI/CD Used to working with SCRUM principles, preferably in JIRA Fluent English Other Details: The role is designed for a cloud-native environment, supporting development across various backend services focused on scalability and security.

🏢 Summary: Senior/Lead Ruby on Rails role focused on leading backend architecture and development while supporting frontend integration with React. The position involves driving technical direction, ensuring scalability and performance, and maintaining high code quality across the project. The role also acts as a technical point of contact aligning engineering outcomes with business goals. 🗂️ Requirements: Mastery of Ruby on Rails, Expert-level Ruby proficiency, Experience designing scalable backend architectures, Experience with React, Proven experience leading technical projects or modules, Ability to conduct code reviews and enforce best practices 📃 Skills: Ruby, Rails, React, Backend, Architecture, REST, Git, SQL 🏢 Description: We are looking for a high-level Ruby on Rails Expert to take a key role in the development team. This position is designed for someone who excels in backend architecture but can also navigate the frontend landscape when needed. As a Senior or Lead Developer, you will be responsible for the technical direction of the project, ensuring high performance, and maintaining a robust codebase while communicating effectively with international stakeholders. Responsibilities Technical Leadership: Leading the backend development lifecycle using Ruby on Rails . Architecture: Designing and implementing scalable, secure, and maintainable backend services. Full-stack Support: Collaborating on the frontend layer, specifically with React (experience here is a big plus). Code Quality: Conducting code reviews, mentoring team members, and establishing best development practices. Communication: Acting as a technical point of contact, ensuring clear alignment between technical goals and business needs. Requirements Expertise: Mastery of Ruby on Rails and the Ruby language. Frontend: Practical experience with React (highly desirable). Ownership: Proven ability to lead projects or significant technical modules. Soft Skills: Proactive attitude, strong problem-solving skills, and a "Lead" mindset.

🏢 Summary: Backend engineering role focused on building scalable backend services, APIs, and internal developer platforms in a fully remote environment. The position involves improving system architecture, optimizing distributed systems, and collaborating across the full software development lifecycle. The offer includes influence on technical decisions, modern technologies, and growth opportunities within an experienced engineering team. 🗂️ Requirements: 5+ years of backend software development experience, Proficiency in PHP or experience with Java, Python, Go, Knowledge of RESTful APIs and GraphQL, Experience building scalable distributed backend systems, Experience with SQL/MySQL and database optimization, Experience with automated testing and monitoring, Knowledge of debugging production systems, Familiarity with contract-driven development, English for daily technical communication 📃 Skills: PHP, Java, Python, Go, REST, GraphQL, SQL, MySQL, React, API 🏢 Description: ✅ Your responsibilities: ・Design, develop, and maintain scalable backend services and APIs for third-party integrations. Improve platform architecture, service communication, and internal developer tooling. Collaborate with Product Managers, Designers, and Engineers throughout the entire software development lifecycle. Optimize existing systems for performance, scalability, reliability, and maintainability. Drive engineering best practices, including code quality, testing, and documentation. Participate in architecture discussions and technical decision-making. Mentor engineers through code reviews, pair programming, and knowledge sharing. Continuously improve the developer experience by building reliable internal platforms and tools. 🧠 Our requirements: 5+ years of experience in backend software development. Strong proficiency in PHP (preferred) or solid experience with Java, Python, Go , or similar backend technologies. Strong understanding of RESTful APIs , GraphQL , and API design best practices. Experience designing and building scalable, distributed backend systems. Hands-on experience with SQL/MySQL databases and database optimization. Experience with automated testing, observability, monitoring, and debugging production systems. Familiarity with contract-driven development and modern software development practices. Basic knowledge of frontend technologies such as React is a plus. Strong communication skills and the ability to collaborate across cross-functional teams. Passion for writing clean, maintainable, and high-quality code or AI automation English at a level allowing daily technical communication 🌟 What we offer: 100% remote work. Private healthcare and Multisport. Life insurance. Real influence on technical decisions and system architecture. Opportunity to build scalable backend services and developer platforms. Work with modern technologies in a collaborative engineering environment. Knowledge sharing, mentorship, and professional growth opportunities. Friendly, supportive, and experienced engineering team.

🏢 Summary: Senior Backend Engineer role focused on defining the technical direction and architecture of a domain within a borderless financial platform. The position involves designing scalable microservices, driving architectural decisions, and leading a small backend team in a distributed environment. The role emphasizes reliability, security, and high‑volume transaction processing in a cloud-based ecosystem. 🗂️ Requirements: 4-7 years backend engineering experience, Proficiency in Go, Experience with Java 21 or modern Java, Experience designing microservices with clear contracts, Experience with caching strategies including TTL and invalidation, Experience with event-driven or asynchronous architectures, Experience with structured logging, metrics, and alerting, Experience with AWS services, Experience with relational and non-relational databases, Experience with Spring Boot or similar frameworks, Experience reviewing code and architectural decisions, Availability to work in GMT+5:30 timezone 📃 Skills: Java, Go, Spring, JDBI, PostgreSQL, CockroachDB, DynamoDB, Redis, SQS, SNS, Kafka, AWS, EKS, ALB, RDS, S3, Kong, Datadog, Quickwit, JWT, RBAC, TLS, Docker, ArgoCD, GitHub, Microservices, Kafka, CDC 🏢 Description: Project overview This project focuses on developing a borderless financial platform that supports international banking flows, payments, account management and regulatory compliant operations. The product handles sensitive data and high volume transactions while prioritising reliability and security. Team You will work in a distributed environment with backend engineers, a product manager and platform specialists. The role involves leading a sub team of three to five engineers, conducting design reviews, ensuring code quality standards and supporting collaborative decision making. Position overview We are looking for a Senior Backend Engineer who will define the technical direction of a backend domain and drive architectural decisions. You will design microservices, create scalable solutions, guide a small engineering group and collaborate closely with product specialists to shape the delivery roadmap. We are looking for a person willing to work in the time zone: GMT+5:30. Technology stack Java 21, Go, Spring Boot, JDBI, custom workflow engines, PostgreSQL, CockroachDB, DynamoDB, Redis, SQS, SNS, Kafka, AWS EKS ALB RDS S3 Secrets Manager, Kong API Gateway, Datadog, Quickwit, JWT RBAC TLS request and response encryption VAPT, GitHub Actions, Docker, ArgoCD, microservices, event driven architecture, saga and orchestration patterns, CDC pipelines, maker checker workflows Responsibilities Plan and design backend microservices with clear boundaries and contracts Develop solutions for domains such as onboarding, payments, transaction orchestration or platform components Break complex epics into actionable tasks with clear acceptance criteria Review designs from other engineers to ensure scalability and fault tolerance Drive technical decisions including caching layers, asynchronous processing strategies, database choices and API versioning Evaluate build versus buy options for integrations and services Collaborate with a product manager to align on scope and prioritisation Lead a sub team of backend engineers and support their professional growth Support incident response, root cause analysis and long term improvements Monitor service performance using logging, metrics and tracing tools Requirements Professional backend engineering experience from 4-7 years Experience with Go (tooling & CLIs) Experience designing microservices with well-defined contracts and boundaries Experience with Java 21 or modern Java versions Experience with caching strategy design, including TTL and invalidation approaches Experience working with asynchronous processing, event-driven architecture, or queue-based workflows Experience using structured logging, metrics, and alerting to debug production systems Experience in making build versus buy decisions with clear trade-off analysis Experience reviewing code and identifying architectural or contract issues Experience with AWS-based services Experience working with relational and non-relational databases such as PostgreSQL or DynamoDB Experience writing backend services using Spring Boot or similar frameworks Nice to have Experience with financial or payments related systems Experience with KYC or AML flows Experience with workflow or orchestration engines Experience with platform wide pattern creation or reusable service design Experience with data encryption practices and security audits Experience with CockroachDB or high availability distributed databases What We Offer: Vacation days : Up to 26 business days per year. 10 illness/special days off per year (fully paid, no medical papers needed) for all contract types Health and life insurance (Luxmed) MyBenefit platform with Multisport option Internal psychological support service English language classes from the first working day Access to external learning platforms : O’Reilly, LinkedIn Learning, Udemy, and a wide catalog of diverse internal training Flexible workplace : work from the office, from home, or choose a hybrid option Tech Skills Mentoring Program Opportunities to develop as a public speaker, mentor, or technical interviewer Fully paid idle (bench) when not involved in a project Certification reimbursement (AWS, GCP, Microsoft, etc.)

🏢 Summary: Senior Backend Engineer role focused on designing and scaling a high-throughput, event-driven platform. The position centers on building and optimizing large-scale event processing services and APIs in distributed systems. It involves solving complex scalability and reliability challenges in a massive-scale environment. 🗂️ Requirements: Senior-level experience in backend development, Strong Python expertise, Experience scaling message queue systems, Experience with distributed systems and microservices architecture, Proven track record building high-throughput backend services, Experience designing scalable and fault-tolerant systems, Ability to implement and optimize APIs 📃 Skills: Python, Azure, ServiceBus, StorageQueues, EventHubs, Microservices, DistributedSystems, APIs, EventDriven, EventSourcing, Streaming, Observability, Monitoring 🏢 Description: Location: Remote Type: Full-time Level: Senior Duration: 4 months Start: ASAP We are looking for an experienced Senior Backend Engineer to join a team responsible for building and scaling a high-throughput, event-driven platform operating at massive scale. Your primary focus will be the event processing backbone — designing, developing, and optimizing services that handle large volumes of messages reliably and efficiently. You will work closely with architects and other senior engineers to implement APIs that expose data and support advanced triage and processing workflows. This role is ideal for someone who enjoys solving hard scalability problems , working with distributed systems, and building resilient backend services that operate under real-world load. Responsibilities Design and build backend services responsible for large-scale event processing Optimize and scale message-based systems to handle high throughput and reliability requirements Implement APIs defined by system architects to expose data and collect processing results Collaborate with cross-functional teams to improve platform performance and resilience Contribute to architectural decisions around scalability, fault tolerance, and observability Core Skills Strong experience with Python as a primary backend language Deep expertise in scaling message queue systems (e.g. Azure Service Bus, Storage Queues, Event Hubs or similar) Solid understanding of microservices architecture and distributed systems Proven experience building high-throughput, resilient backend services Strong problem-solving skills and ability to work with complex systems Highly Desirable Experience with event-driven or event sourcing architectures Background in data processing frameworks or streaming systems Experience building platforms related to observability, monitoring, or large-scale event management Familiarity with designing systems for fault tolerance and graceful degradation What we offer Work on technically challenging systems operating at very large scale High level of autonomy and real influence on system architecture Collaboration with experienced engineers in a mature engineering environment Competitive compensation and flexible working model Project with strong technical ownership

🏢 Summary: Senior engineer role focused on designing and implementing backend services and APIs for new payment models and authorization systems in a high-availability, high-security environment. The position involves architectural design, technology selection, building production-grade solutions and proof-of-concepts, and creating scalable, secure integrations. The role also supports testing and deployment processes while contributing to mission-critical payment infrastructure. 🗂️ Requirements: Minimum 10 years experience as backend/full-stack/system engineer, Proficiency in at least two programming languages, Strong knowledge of API design, Experience with microservices architecture, Experience with messaging queues and event-driven systems, Experience with SQL and NoSQL databases, Experience building complex system integrations, Experience in high-availability environments, Experience in high-security environments, Experience with Open Source technologies, Ability to design secure and scalable services 📃 Skills: API, Microservices, SQL, NoSQL, Queues, Event-driven, Blockchain, Ethereum, Hyperledger, Cosmos, Substrate, ITIL, RAG, AI, Low-latency, Real-time, Tokenization 🏢 Description: Twój zakres obowiązków Projektowanie oraz implementacja usług backendowych i API dla nowych modeli płatności oraz systemów autoryzacyjnych. Tworzenie prototypów i usług integracyjnych działających w środowisku o wysokiej dostępności. Współpraca z liderem technicznym przy projektowaniu architektury nowych rozwiązań. Uczestnictwo w procesie analizy technologicznej i wyborze narzędzi. Tworzenie kodu produkcyjnego oraz proof-of-concepts dla nowych funkcjonalności. Dbanie o bezpieczeństwo, skalowalność i jakość implementowanych usług. Współpraca z osobą odpowiedzialną za warstwę biznesowo-regulacyjną oraz z pozostałymi członkami zespołu technicznego. Wspieranie procesów testowych i wdrożeniowych Nasze wymagania Minimum 10 lat doświadczenia w roli backend software engineer / full-stack engineer / system engineer. Bardzo dobra znajomość przynajmniej dwóch języków programowania. Zdrowe fundamenty architektoniczne: API design, mikroserwisy, kolejki, zdarzenia, bezpieczeństwo usług. Umiejętność pracy z bazami danych (SQL/NoSQL) oraz tworzenia złożonych integracji. Samodzielność w prowadzeniu prac projektowych oraz zdolność do działania w obszarach bez gotowych rozwiązań. Doświadczenie w pracy w środowiskach o podwyższonym rygorze bezpieczeństwa lub wysokiej dostępności usług. Doświadczenie w pracy z technologiami Open Source. Umiejętność czytania i rozumienia dokumentacji technicznej oraz proponowania rozwiązań. Mile widziane Znajomość wyzwań związanych z low-latency, event-driven architecture, real-time processing. Znajomość technologii blockchain (Ethereum, Hyperledger, Cosmos, Substrate itp.). Znajomość zagadnień ITIL lub posiadanie podstawowych certyfikatów. Rozumienie tokenizacji aktywów, modeli emisji, systemów rejestrów. Praca z agentami AI, orchestratorami, RAG, systemami wektorowymi. Tworzenie botów lub API do automatycznych agentów wykonujących procesy decyzyjne. To oferujemy Pracę przy jednym z najważniejszych systemów płatniczych w Polsce, który codziennie obsługują miliony użytkowników. Realny wpływ na bezpieczeństwo i dostępność usług płatniczych. Możliwość rozwoju kompetencji technicznych i operacyjnych. Przyjazne środowisko, nastawione na współpracę i ciągłe doskonalenie. Elastyczne godziny pracy oraz model hybrydowy. Pakiet benefitów (opieka medyczna, ubezpieczenie, język angielski, platforma e-learningowa, MyBenefit, MultiSport). Budżet rozwojowy i dostęp do szkoleń branżowych.