Senior Backend Engineer

Company Description Join a project that helps make digital products accessible to millions of users worldwide. We are looking for a Senior Back-end Engineer to contribute to the development of a high-scale SaaS platform focused on accessibility automation and compliance. As part of Sigma Software, you will work remotely with distributed teams across Ukraine, Poland, Romania, and Albania while contributing to cloud-native and data-intensive solutions built with modern Back-end technologies. This role combines hands-on engineering, architecture evolution, and infrastructure decision-making in a fast-growing product environment. We at Sigma Software create opportunities for engineers to influence technical strategy, work with modern technologies, and grow within an international engineering community focused on meaningful products and long-term collaboration. CUSTOMER Our Customer is a rapidly growing technology company specializing in digital accessibility solutions for enterprise web and mobile products. Its AI-enabled software helps organizations identify, analyze, and resolve accessibility issues across digital platforms while integrating directly into software development pipelines. Due to NDA restrictions, the Customer name cannot be publicly disclosed. PROJECT The project focuses on scaling a modern SaaS platform used by enterprise customers worldwide. The team is developing distributed Back-end services with a strong emphasis on microservices architecture, cloud infrastructure, large-scale data processing, and high system reliability. The platform leverages AI-driven analysis to automate accessibility compliance and improve development workflows. You will contribute to architecture evolution, cloud infrastructure improvements, and optimization of high-load distributed systems while collaborating closely with international engineering teams. Job Description Design and implement scalable, distributed Back-end solutions for a SaaS platformArchitect and deliver complex systems focused on accessibility compliance and platform scalabilityDevelop and maintain microservices and cloud-native applicationsPlan, execute, and support large-scale software delivery pipelinesMonitor system health, troubleshoot production issues, and optimize service performanceResearch, evaluate, and integrate modern technologies into the Back-end ecosystemCollaborate with cross-functional teams on architecture evolution and technical strategyContribute to infrastructure and SaaS architecture decisionsImprove reliability, scalability, observability, and maintainability of distributed systemsUtilize AI-assisted development practices and tools within the software delivery lifecycleParticipate in code reviews, technical discussions, and engineering best practices initiatives Qualifications 5+ years of experience as a Software Engineer including at least 1 year of extensive AI SDLC experienceStrong Back-end development experience in at least 2 of the following programming languages: Golang (primary), Kotlin, or other JVM-based languagesHands-on experience with AI coding tools such as Claude Code, Cursor, Microsoft Copilot, or similarProficiency with at least one major cloud provider such as GCP, AWS, or Azure, including serverless and container-based deploymentsSome experience with Elasticsearch and BigQueryFamiliarity with multiple data stores and services including SQL, NoSQL, Elasticsearch, BigQuery, etc.Proficiency with at least one messaging or streaming system such as Kafka, Flink, Spark, Pub/Sub, or RabbitMQKnowledge of high-scale stream and batch processing systems including Flink, Spark, and KafkaStrong background in microservices architecture, distributed systems, serverless solutions, and high-scalability systemsFamiliarity with production monitoring and performance optimizationFamiliarity with CI/CD pipelines and deployment processesAt least Upper-Intermediate level of English WILL BE A PLUS Familiarity with ClickHouseExperience in Full Stack and/or Front-end developmentExperience with accessibility-related products or compliance-focused systemsExperience working with AI-enabled SaaS platforms Additional Information PERSONAL PROFILE Independent and proactive mindsetStrong problem-solving skillsPassion for learning and adopting new technologiesExcellent communication and collaboration skillsTeam-oriented attitude with commitment to high-quality deliveryAbility to work effectively in a fast-paced and evolving environment