Role Description Ciklum is looking for a Senior JavaScript Engineer to join our team full-time in Ukraine. As a Senior JavaScript Engineer, become a part of a cross-functional development team working for the global leader in leisure, travel, and tourism industries that offers a high-quality end-to-end customer experience, from booking to accommodation and transportation. Responsibilities - Design and implement complex web applications using the established approaches and best practices - Improve existing engineering and quality standards in a team and help other team members adopt them - Create CI/CD pipeline by template and/or assist DevOps team in creating more complex pipelines - Participate in the hiring process and technical interview activities - Coach/supervise middle/junior engineers by demand of the project Qualifications - Experience in designing solutions for complex features and creating documentation - Strong experience with MicroFrontend architecture - Strong experience in using AI coding assistants like Amazon-Q or similar (Github Copilot, Claude Code) - Uses the established standards and algorithms for implementing the application - SOLID / GRASP principles - Architectural Diagram Literacy (e.g., C4 model, Basic UML) - Data Structures and Formats - Common algorithms - Web Scaling Essentials (e.g., Load Balancers, Caching strategies, CDN) - Serverless / Microservices / Modular Monolith - CDN (Content Delivery Network) - Proficient in HTML, CSS, and JavaScript - Practical use of advanced features in React - Experience in refactoring existing applications according to new requirements - TypeScript - Browsers (DOM, Storages, Events) - WebComponents - Package management (npm) - ReactJs / Preact - CSS Preprocessors (SCSS) - Responsive and Adaptive Design Layout - Accessibility - UI Performance Optimization (Web Vitals) - Experience in configuring CI/CD pipelines (TravisCi, GitLabCI, etc.) - Collaborates with the DevOps team to set up the custom CI/CD pipeline - Bundlers & Builders (Rollup or Esbuild or SWC) - Docker - GitLab (MR, Pipeline, UI, Configuration, Tokens) - Branching strategies - DataDog - Monitoring and Logging tools - Downtime forecast - Shell script basics - Continuous Integration / Continuous Deployment / Continuous Delivery Requirements - Hands-on experience with testing approaches and tools - Ability to adjust and maintain the code quality rules and metrics - Automated tests (unit, integration, e2e tests) - Common manual test practices - Jest or similar - Static code analysis: (ES)Lint - Code review - SonarQube - API Contract Testing - Agile (Principles, Scrum, Kanban) - Tech Risk Management - Technical Debt Management (Refactoring, Improvements) - Serverless in AWS - AWS CDK / CloudFormation - Modern IDEs (setup plugins, configuration) - Postman or similar - DevTools (Chrome DevTools or similar) - UI Design Tools (e.g., Zeplin, Figma, Sketch) - NodeJS Security (npm audit, vulnerability scanners) - Web Security (XSS, CSRF, CSP, Injections) Personal Skills - Works under general direction, accepts guidance and has work reviewed at agreed milestones - Has working-level contact with customers and colleagues - May supervise others or make decisions which impact the work assigned to individuals or phases of projects - Performs a range of work, sometimes complex and non-routine - Demonstrates effective communication skills - Plans, schedules and monitors own work (and that of others where applicable) competently - Contributes fully to the work of teams Benefits - Strong community: Work alongside top professionals in a friendly, open-door environment - Growth focus: Take on large-scale projects with a global impact and expand your expertise - Tailored learning: Boost your skills with internal events (meetups, conferences, workshops), Udemy access, language courses, and company-paid certifications - Endless opportunities: Explore diverse domains through internal mobility, finding the best fit to gain hands-on experience with cutting-edge technologies - Flexibility: Enjoy radical flexibility – work remotely or from an office, your choice - Care: We’ve got you covered with company-paid medical insurance, mental health support, and financial & legal consultations Company Description At Ciklum, we are always exploring innovations, empowering each other to achieve more, and engineering solutions that matter. With us, you’ll work with cutting-edge technologies, contribute to impactful projects, and be part of a One Team culture that values collaboration and progress. As one of Ukraine’s largest IT companies and a top employer recognized by Forbes, we’ve spent over 20 years delivering meaningful tech solutions. We proudly support diverse talent and military veterans, recognizing their unique skills and perspectives they bring to shaping the future. Explore, empower, engineer with Ciklum!

• Provide pre-sales and post-sales technical support to AI data center customers and partners. • Collaborate with sales teams to identify customer requirements and translate them into technical solutions. • Develop and optimize system architectures for integrating Skeleton's ultracapacitors into AI data center UPS, backup power, and energy efficiency applications. • Conduct on-site visits, technical trainings, and product demonstrations. • Support system design, including electrical schematics, thermal considerations, and lifecycle cost analysis. • Work closely with R&D and Product Development to communicate field feedback and improve product-market fit. • Prepare technical documentation including specifications, integration guides, and white papers tailored for the AI data center market. • Ensure compliance with relevant industry standards and certifications.

Role Description We're looking for an Application Engineer to be Skeleton's technical face to AI/hyperscale data center customers across Europe. This is a technical leadership role, not a support function - you'll own the relationship from first conversation to signed deal, and be trusted to represent Skeleton in front of senior engineering and procurement stakeholders. - Provide pre-sales and post-sales technical support to AI data center customers and partners. - Collaborate with sales teams to identify customer requirements and translate them into technical solutions. - Develop and optimize system architectures for integrating Skeleton's ultracapacitors into AI data center UPS, backup power, and energy efficiency applications. - Conduct on-site visits, technical trainings, and product demonstrations. - Support system design, including electrical schematics, thermal considerations, and lifecycle cost analysis. - Work closely with R&D and Product Development to communicate field feedback and improve product-market fit. - Prepare technical documentation including specifications, integration guides, and white papers tailored for the AI data center market. - Ensure compliance with relevant industry standards and certifications. Qualifications - Bachelor's or Master's degree in Electrical Engineering, Power Systems, or a related technical field. - 3+ years of experience as an application or field engineer in the data center or power infrastructure industry. - Strong knowledge of power backup systems, UPS, batteries, and/or ultracapacitors. - Familiarity with thermal management, grid-tied systems, and the operational requirements of high-density AI compute environments. - Excellent communication skills, both written and verbal - comfortable explaining technical concepts to non-technical stakeholders and clients. - Ability to travel for customer meetings and site support, including internationally. Benefits - Flexible working hours, with the possibility of mobile working without core working hours and sufficient freedom for your own ideas. - A flat hierarchy culture - fostering our great working atmosphere. - A motivating opportunity for continuous growth at Skeleton. - An additional day off every year for your birthday. Company Description Skeleton Technologies is a global leader in critical power infrastructure for AI data centers and electrical grid stability, founded in 2009. Power today is more than electricity. It is national security, digital continuity, and economic resilience. Skeleton is the Backbone of Power: equipping AI data centers, electrical grids, defense systems, and critical infrastructure with the resilience to withstand surges, instability, and failure. Our power systems protect GPU clusters from millisecond-level spikes, enable hyperscalers to run at higher rack densities without grid compromise, and make AI data centers up to more 40% energy efficient. We keep the lights on when grids fluctuate, stabilising electrical infrastructure under the combined pressure of accelerating renewable energy deployment and surging AI demand. When power fails, critical operations stop. We exist to prevent that in microseconds. Powering the infrastructure that powers everything else.

• Provide security engineering support for web and API applications. • Integrate security controls into Secure SDLC, including threat modeling and security design reviews. • Ensure adherence to organizational security standards and best practices. • Administer and manage vulnerability scanning tools (e.g., Tenable or similar). • Configure, tune, and maintain scanning policies and schedules. • Optimize tool performance to improve accuracy and reduce false positives. • Implement and maintain SAST and DAST tools within CI/CD pipelines. • Collaborate with engineering teams to ensure seamless integration and actionable outputs. • Identify and validate vulnerabilities through automated and manual testing. • Perform false-positive analysis and assess exploitability. • Review scan results and track vulnerabilities to closure. • Coordinate with development teams for timely remediation. • Validate vulnerabilities using manual testing and offensive security methods. • Document attack paths, reproduction steps, and impact clearly. • Perform manual and automated security testing for applications and APIs.