Sr Back End Engineer for Streaming Data Platform (Poland) (#APR26)

KOR Financial

8h • Remote

About The Position

KOR is a VC-backed fintech company with a live product in regulatory trade reporting, serving a growing list of institutional clients (B2B). The company is rapidly scaling, with product expansion planned across the US, Canada, UK, EU, Australia, and Singapore. KOR leverages leading-edge cloud technology and boasts a team of industry domain experts and world-class in-house engineers. Their mission is to innovate B2B trade servicing, starting with regulatory reporting, by providing fresh designs and solutions to data utility, quality, and processing inefficiencies, thereby unlocking significant value for clients. Teamwork and a laser focus are central to KOR's culture, believing in empowering small, independent teams with deep expertise to achieve better results and foster career growth. The company operates by the mantra of 'work humble, work smart, and work together'. The ideal candidate has a passion for high-quality, reliable, and maintainable code, is comfortable collaborating with product managers, designers, and clients, and can make decisions to deliver valuable software quickly. They are agile and retrospective, willing to identify areas for improvement, and measure success by team achievement and customer satisfaction.

Requirements

• A minimum of 8+ years of experience as a Back End Engineer
• Experience with Java and Spring Boot
• Experience with building and running applications on public cloud vendors like AWS
• Working experience with one or more of the following technologies: Kafka, Kafka Streams processor API (not high-level DSL), DataBricks, EMR, DeltaFlow
• Experience profiling, debugging, and performance tuning complex distributed systems
• Willingness to closely collaborate by pairing
• A firm reliance on unit testing and mocking frameworks with a TDD (Test Driven Development) mindset
• Knowledge of OOP principles and modern development practices
• An open-minded, humble, driven, communicative team player

Nice To Haves

• Experience with horizontally scalable and highly available system design and implementation, focusing on performance and resiliency
• Bachelor's Degree or higher in Engineering, Computer Science, or Information Technology, or similar through experience

Responsibilities

• Designing and implementing the streaming data platform engine and SDK
• Implementing new features for our range of web and streaming applications and data reporting capabilities
• Be an active voice in the platform's build-out in regards to the technical choices and implementations
• Working closely with the broader team to embrace new challenges and adapt requirements as we continue to grow and adjust priorities
• Using Claude Code and other AI tools responsibly to boost productivity
• Paired programming with a growing team of Back-end, Data, and Front-end Engineers

Benefits

• Working directly with seasoned international engineers with experience at companies like Pivotal (including ex-Spring team members), VMware, Confluent (including Kafka committers), and Apple
• Culture of trust, kindness, empowerment, and constructive feedback
• Competitive salary, great IT equipment, and expense allowance
• Flexible working times
• Fully remote, with fun social activities and gatherings
• A span of control that matches your ambitions and skills
• Commitment to a genuine, balanced relationship
• Support to grow professionally

What This Job Offers

• Job Type: Full-time
• Career Level: Senior