Jaewon Kim

Server Developer @ Toss

South Korea

About

Versatile backend engineer with 7+ years of hands-on experience crafting effective solutions across diverse tools, environments, and architectures. Skilled in designing reliable, scalable systems and building data pipelines for both real-time and batch processing. Experienced in modernizing legacy platforms, improving team workflows, and driving operational efficiency through automation. Strengths: • Strong problem-solver, analyzing and resolving complex issues • Excellent collaborator, fostering effective teamwork across functions • Analytical thinker, leveraging data to drive informed decisions

Experience

  • Server Developer at Toss
    Sep 2025 - Present · 11 mos

  • Data Pipeline Team Lead at AB180 - 에이비일팔공
    Aug 2018 - Aug 2025 · 7 yrs 1 mo

    A martech company building Airbridge, a Mobile Measurement Partner (MMP) platform for campaign tracking and attribution. Lead Backend Engineer (Jan 2022 – Aug 2025) • Led a team of backend engineers responsible for the company’s core data pipeline and infrastructure • Rearchitected legacy Python services into high-performance Golang and Rust microservices, greatly improving stability and throughput • Migrated large-scale identity mapping data to a new storage system, significantly improving scalability and reducing costs • Improved incident response and reliability through automation and streamlined postmortem processes • Built internal tools to automate operational tasks, reducing manual effort and enhancing cross-team productivity Backend Engineer (Aug 2018 – Dec 2021) • Developed and maintained microservices for real-time processing of over a billion daily events, ensuring reliability and accuracy • Designed and implemented a scalable snapshot testing framework, widely adopted by the team and shared at GopherCon • Built a robust, adaptable anti-fraud system supporting diverse customer use cases • Delivered a full data pipeline for marketing analytics models under tight timelines, contributing directly to business impact • Improved data pipeline processes and compliance workflows using dbt and CI, reducing maintenance load across hundreds of data views

  • Mentee at SW Maestro
    2018 - 2018 · Less than a year