Ciklum is looking for a Senior JavaScript Engineer to join our team full-time in Ukraine. We are a custom product engineering company that supports both multinational organizations and scaling startups to solve their most complex business challenges. With a global team of over 4,000 highly skilled developers, consultants, analysts and product owners, we engineer technology that redefines industries and shapes the way people live. About the role: As a Senior JavaScript Engineer, become a part of a cross-functional development team engineering experiences of tomorrow. You will join a highly motivated team and will be working on a modern solution for our existing client. We are looking for technology experts who want to make an impact on new business by applying best practices and taking ownership. Responsibilities: - Delivery. Create and maintain modern interfaces according to unit standards - Code Quality. Follow and improve code quality standards - Analyze and Estimate. Perform technical assessment of UI mockups/wireframes to ensure the possibility of their implementation within a reasonable time - Software Design. Create and review software feature design documents and provide the solution - Contribute ideas through your knowledge of evolving front-end technologies - Be proactive in communication with team members and client - Use industry best practices of development processes & tools, adopt and improve them - Mentorship of junior colleagues - Take responsibility for project delivery, playing the role of the most senior technical person (by stack) at the project - Direct client communications - Set up efficient development workflow throughout proactive collaboration with any project role (ProjectManager, BA, PO, UX, UI, Arch, BE, DevOps) - Technical organisation: interview, tech audit, pre-sale - Problem solving, Solution Presentation, Meeting and Visual Facilitation Requirements: You can name examples of use in different contexts. Are guided by best practices and specifications of such skills: - Strong experience in applying and suggesting best practices and design patterns - Strong experience with MicroFrontend architecture - Strong experience in using AI coding assistants like Amazon-Q or similar (Github Copilot, Claude Code) - Strong expertise in JS, React (Node, Eleventy, NJK would be a plus) - Understanding and experience with SDLC phases : Requirement analysis, Planning Software design(such as architectural design), Software development,Testing Deployment - Deep knowledge of HTML5, CSS3/SCSS, UI and UX design principles - Good experience in understanding, refactoring, writing and using a CI/CD pipeline - Good experience in cloud platform services (as a producer and consumer) - Good experience in identifying performance issues - Good experience in Monitoring and Alerting - Implementation of tests: unit, integration, component, contract - Customer-centric, passionate about delivering great digital products and services - Demonstrating a true software craftsmanship mindset - Passionate about continuous improvement, collaboration and great teams - Compelling coaching and training skills for imparting professional software engineering skills - Strong problem-solving skills coupled with good communication skills - Understanding of the social and ethical implications of software engineering - Open-minded, inquisitive, life-long learner - Comfortable with ambiguity, highly autonomous Desirable: You should have an idea of the subject and its parts. Can explain. Has experience of use of such skills: - Experience with API Gateway - Experience in building auto-scaling and self-healing components - Experience in the implementation of the Testing Pyramid - Experience in Automation Systems - Integration with Microservices through BFF or Facade - Cloud services (AWS/Azure/GCP) - Testing - Infrastructure (Autoscaling, Self Healing, Configuration Properties) - Authentication & Authorisation - General Security knowledge (TLS/MTLS, Vault, Secret Rotation, Security toolings) 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 What`s in it for you? - 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 About us: 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. Want to learn more about us? Follow us on Instagram, Facebook, LinkedIn. Explore, empower, engineer with Ciklum! Interested already? We would love to get to know you! Submit your application. We can’t wait to see you at Ciklum.

• Design & ship mission grade GenAI: Build agentic workflows and RAG systems tailored to mission data and environments; target low hallucination, tight p95 latency, and predictable cost. • Agent frameworks & orchestration: Apply patterns from LangChain/LlamaIndex/Semantic Kernel; design task decomposition, tool use, guardrails, and recovery/fallback strategies. • Platform integration (no model training): Implement with AWS Bedrock, Azure OpenAI, Google Vertex AI, Amazon Kendra, and managed services (e.g., Document AI, Gemini, Gemma). • LLM selection & evaluation: Compare models for quality, safety, latency, cost; author/test prompts & policies; deploy with observability and safe rollback/fallback. • RAG done right: Build retrieval pipelines & vector search (Pinecone, Weaviate, OpenSearch, pgvector, FAISS/Chroma); handle data prep, chunking, metadata, and IRstyle evals (e.g., NDCG) to maximize signal to noise. • Production rigor: Instrument metrics/logs/traces; run A/B experiments; maintain incident playbooks; and implement safety & compliance guardrails. • SRE & FinOps for AI: Define SLIs/SLOs (quality/latency/safety/cost), run on call and postmortems, reduce MTTR; meter usage and optimize token/spend. • Reusable platform components: Ship SDKs, CI/CD templates, Terraform/IaC modules, evaluation harnesses that accelerate multiple mission team not one-off projects. • Operate in real world constraints: Deliver into hybrid, restricted, or air gapped environments with Zero Trust principles and audit ready controls.

• Define and execute security strategy for product teams, aligning with business objectives. • Lead threat modeling, security architecture reviews, and design guidance for diverse software projects. • Mentor engineers technically and professionally, fostering a culture of security excellence. • Conduct adversarial security analysis using automated tools and manual techniques (e.g., custom exploit development). • Perform manual/automated secure code reviews across Java, Python, JavaScript, and cloud-native stacks. • Develop security automation tools to scale vulnerability detection (SAST/DAST/IAST enhancements). • Identify complex risks through offensive security research; advocate for cutting-edge mitigation technologies. • Solve novel security problems lacking predefined solutions (e.g., zero-day vulnerabilities, emergent attack vectors). • Maintain and evolve threat models for critical applications and microservices architectures. • Partner with the engineering team to embed security controls into CI/CD pipelines and development practices. • Design/deliver security training programs tailored to development teams and business stakeholders. • Lead incident response for application security events and drive root-cause analysis.

• Drive the technical design, architecture, and strategy for multiple core BPM product areas. • Take full accountability for the performance, reliability, and scalability of the systems under your purview throughout the entire product life-cycle. • Design and implement highly concurrent, multi-threaded Java applications and robust queuing systems. • Architect and manage complex database operations, ensuring transaction atomicity and data consistency across disparate database systems. • Relentlessly profile, troubleshoot, and optimize system performance, providing actionable insights. • Elevate the engineering organization by mentoring senior and mid-level engineers, establishing best practices. • Partner closely with product management to translate business requirements into scalable technical solutions.