• Design and build backend services in Golang • Own critical money-movement flows end to end • Build idempotent, fault-tolerant, auditable transaction processing • Operate within PCI DSS scope • Instrument and monitor payment health

• Design and build backend services in Golang that integrate with payment processors, gateways, and card networks • Own critical money-movement flows end to end: authorization, capture, settlement, refunds, reconciliation, and chargeback/dispute handling • Build idempotent, fault-tolerant, auditable transaction processing within a distributed architecture (transactional outbox patterns; queues such as Kafka, SQS, or RabbitMQ) • Operate within PCI DSS scope — tokenization, network tokens, secure handling of payment data, and 3DS/SCA flows where applicable • Instrument and monitor payment health: authorization/decline rates, processor performance, latency, and settlement accuracy, driving continuous improvement • Use AI tooling (Claude and equivalent LLMs) as part of your daily workflow to accelerate design, coding, research, testing, and documentation — within Sezzle's security and data-handling policies • Mentor engineers and help raise the bar across the team.

Role Description Ciklum is looking for a Lead Full Stack Engineer to join our team full-time in Ukraine. As a Lead Full Stack Engineer, become a part of a cross-functional development team engineering experiences of tomorrow. Ciklum is building a team to work on various projects which primary goal is to improve and automate the customer’s business processes, reduce time and efforts required for various operations. The team shall be working in coordination with the Client’s office in Israel. The team will be responsible for the whole development cycle – based on requirements, you will take part in design and development and the team shall also own testing until the feature or component is ready for production. You will learn the Client's development environment as well as the relevant business logic per feature. We’re looking for a technology enthusiastic Team Leader with a drive for excellence and out of the box mindset to satisfy business needs in a complex payment solution environment. - Collaborate closely with Product, DevOps, Support and other R&D teams - Lead a team of software engineers who are working closely with product management for achieving business goals - Putting special focus on team growth challenges - Provide technical authority to your team by demonstrating a hands-on leadership style - Responsible for the overall design, development, architecture, code quality and production environment deployment of your team Qualifications - B.Sc in computer science or equivalent - 7+ years’ experience as a server side developer - all the way from DB to UI (Using C#, .net, REST WEB API and Queues) - 5+ years’ experience with advanced SQL (MSSQL/Oracle/MySql) and NoSQL (e.g. MongoDB) - Experience with frontend technologies: ASP.NET, Angular, React - Experience with distributed systems/microservices - Broad knowledge of OOP and design patterns - Good understanding of network interactions (protocols, conventions (e.g. REST, RPC), authentication and authorization flows) - Experience in engineering best practices (code-reviews, testing coverage, agile methodologies) - Experience with RabbitMQ / Redis / Entity Framework/Kafka - Excellent knowledge of Deployment patterns - Team player attitude and mentality - Experienced and passionate about managing and growing people - 1+ year of managerial/lead experience - Ambitious and eager to learn new things - Good understanding of Agile/Scrum/SAFE 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

Role Description We are seeking a skilled C++ Video Streaming Engineer to develop and improve software for smart cameras. In this role, you will focus on building and optimizing low-latency video streaming solutions that enable reliable, bidirectional communication. Your goal will be to ensure seamless video transmission across diverse and challenging network conditions. Responsibilities and Duties - Design, implement, and optimize embedded video streaming solutions using modern C++ for smart cameras. - Develop and maintain clean, efficient C++17 code for embedded Linux (user-space) and RTOS applications. - Design and maintain robust streaming pipelines and services tailored for resource-constrained IoT devices. - Optimize media delivery for low-latency and resilience against network jitter or packet loss. - Follow Agile methodologies, actively participate in code and architecture reviews, and write technical documentation. - Collaborate closely with cross-functional teams (Hardware, QA, BE) to ensure system integration. Qualifications - At least 5+ years of commercial experience in embedded development with a strong focus on modern C++ (C++17 is a must); experience with Python as an auxiliary language is a plus. - Proven track record in developing/supporting Linux-based (user-space) and/or RTOS-based embedded systems. - Practical experience with UDP/TCP-based communication and a solid understanding of the TCP/IP stack and WLAN. - Familiarity with video streaming protocols (e.g., RTSP, RTP), libraries (e.g., GStreamer), and encoding technologies (e.g., H.264, H.265/HEVC, AAC). - Basic understanding of embedded system security, data encryption, and secure streaming (e.g., SRTP, TLS). - Strong grasp of software engineering principles, clean code practices, and the full SDLC. - Experience using AI-powered tools to enhance productivity and code quality. - At least an Upper-Intermediate level in both written and spoken English (B2). Benefits - The environment of equal opportunities, transparent and value-based corporate culture, and an individual approach to each team member. - Competitive compensation and perks. - Opportunity to receive a Performance Bonus for your individual achievements and a Loyalty Bonus recognizing your dedication to the company. - Gig-contract. - 21 paid vacation days per year, paid public holidays according to Ukrainian legislation. - Development opportunities like corporate courses, knowledge hubs, and free English classes as well as educational leaves. - Medical insurance is provided from day one. Sick leaves and medical leaves are available. - Remote working mode is available within Ukraine only. - Free meals, fruits, and snacks when working in the office.