• Support of the existing extensive code base (microservices) • Development of external connection points to the trading system: backend for interfaces, HTTP API, FIX API • Optimization and modification of the architecture of existing infrastructure to increase productivity and facilitate further maintenance

• Design and maintain data pipelines and ETL/ELT workflows, including batch extraction, transformation, and loading into analytics-ready data stores • Build and operate event-driven, serverless data processing systems using AWS services such as S3, EventBridge, Lambda, and Athena • Develop Python-based data processing components for parsing and transforming data within Lambda environments • Write and optimize SQL queries for data validation and analysis using Athena • Create and maintain embedded analytics dashboards for customer-facing reporting using AWS QuickSight • Provision and manage data infrastructure using Terraform, ensuring consistent deployments across environments • Implement CI/CD pipelines and monitoring/alerting for reliable data platform operations • Extend and improve existing pipeline frameworks while working within legacy systems

Do you thrive on precision and enjoy solving complex problems? Are you excited by the challenge of ensuring data correctness at scale? Join KOR, a VC-backed fintech innovating financial markets with cutting-edge solutions for regulatory trade reporting. About us We are a VC backed fintech with a live product in the regulatory trade reporting space and growing list of institutional clients. Our product journey has started in the US with expanded services covering Canada, UK, EU, Australia and Singapore. If you want to join a scale-up that is going to provide growth and ownership, keep reading. KOR is built on leading-edge cloud technology by industry domain experts and world-class in-house engineering. We're on a mission to innovate B2B trade servicing starting with regulatory reporting in time for a global wave of mandated changes hitting all segments of market participants across OTC derivatives transactions. We’re solving the most challenging problems around by bringing fresh designs and solutions to data utility, quality, and processing inefficiencies. . . while unlocking insane value for clients. Teamwork and laser focus are central to everything we do at KOR. With the right support, we believe small independent teams with deep expertise achieve better results and encourage skilled people to take responsibility and grow their careers. We live by the mantra of work humble, work smart, and work together. About you You have a passion for high-quality, reliable, and maintainable code. You're agile, embrace feedback, and are not afraid to identify what we're doing wrong so we can fix it and what we're doing right to improve on it. Above all, you judge your success by the success of your team and the happiness of our customers. About the role As a Backend Engineer in our Validator Team, you'll focus on maintaining and enhancing our custom-built validator engine. This system ensures regulatory messages sent to financial regulators meet stringent accuracy requirements. The engine uses a JSON-based DSL for both production rules and integration test scenarios, encompassing over a million hand-written test cases. This role involves: - Configuring and maintaining the validator engine to meet jurisdictional requirements. - Extending the rules engine (written in Java) to support new use cases. - Implementing, debugging, and refining JSON-based DSL rules for accuracy and compliance. - Using Claude Code and other AI tools responsibly to boost productivity. - Collaborating with other team members to support ten jurisdictions. - Ensuring thorough testing and validation of all configurations. About You We’re looking for candidates who are: - Detail-oriented perfectionists who take pride in covering all their bases. - Energized by solving repetitive, complex problems systematically. - Open to coaching by senior engineers with deep experience. - Excellent communicators with strong English skills. - Assertive team players who value collaboration. - Bachelor's Degree or higher in Engineering, Computer Science, or Information Technology. - Residing in or near the CET time zone (including Eastern Europe). - Passionate for delivering high-quality, maintainable code. - A minimum of 3+ years of experience as a Backend Engineer. - Experienced with Java and Spring Boot Framework, and eager to learn quickly under mentorship. - Demonstrating a firm reliance on unit testing and mocking frameworks. - Self-motivated and take ownership of their work. While prior experience with DSLs or regulatory systems is a plus, it’s not required. What matters most is your enthusiasm to learn and deliver excellence. What we have to offer Depending on you and your priorities, we offer the following: - Mentorship by senior engineers with experience at companies like Pivotal (including ex-Spring team members), VMware, Confluent (including Kafka committers), and Apple. - The chance to join a rapidly growing team with the opportunity to move into the broader engineering organization. - A collaborative, remote-friendly environment. - Culture of trust, kindness, empowerment, and constructive feedback. - Competitive salary, great IT equipment, and expense allowance. - Flexible working times. - Fully Remote. - A span of control that matches your ambitions and skills. Above and beyond this, we will provide a commitment to a genuine, balanced relationship. We will listen to you, take your needs and wishes seriously, and work to help you grow professionally. Apply Now If you’re excited by the prospect of building a career with us and playing a key role in innovating financial markets, we’d love to hear from you. Reach out today for a chat!

• Own and evolve the backend architecture for IoT projects: from data ingestion pipelines to API design to infrastructure decisions • Make technical trade-off decisions and defend them clearly to the team and to clients • Design and maintain cloud infrastructure on AWS (EKS, Aurora, DynamoDB, Timestream, S3) with production-grade reliability • Lead technical discussions: RFCs, architecture reviews, post-mortems. Not because someone asked you to, but because you see the need • Mentor other backend engineers, raise the bar on code quality, and set patterns others can follow • Collaborate closely with firmware engineers, mobile developers, QA, PMs, and clients • Use AI tools as part of your daily workflow, not as a party trick • Challenge product and technical assumptions when something doesn’t make sense, even if it means a harder conversation