Jinseong Hwang
Backend Developer at 강남언니 팀
Seoul, South Korea
Summary
👤
Senior🎓
Top SchoolJinseong Hwang is a backend developer with 9 years of experience building high-throughput, mission-critical systems across payments, tax platforms, and ad services from Seoul. He led migrations from legacy stacks to Kotlin/Spring Boot and drove performance improvements—speeding a 20-year-old fee calculation system handling ~2.5M daily transactions by 10x while keeping it live. At Toss Income he spearheaded a next-generation tax refund engine, combining deep domain knowledge of Korean tax rules with first-principles design and rigorous testing to cut errors and accelerate feature delivery. Known for rapid learning and cross-domain versatility, he blends hands-on coding with agile team leadership to translate complex policies into maintainable domain models. Outside work his terse GitHub motto, “Keep looking. Don't settle.” reflects a continuous-improvement mindset that shapes both product and engineering craft.
9 years of coding experience
5 years of employment as a software developer
학사 컴퓨터과학, 학사 컴퓨터과학 at Yonsei University
Korean, English
Stackoverflow
61reputation
56kreached
3answers
1question
Github Skills (94)
creator10
http-client10
rpc-server10
time-travel10
micro-framework10
rpc-library10
retrofit10
http-server10
gateway10
kotlin10
soa10
reactive9
javascript9
thrift9
protobuf9
Programming languages (7)
Github contributions (5)
progresivoJS/LeetCode
Nov 2017 - Jun 2018
Contributions:2 PRs, 147 pushes, 2 branches in 6 months
cppleetcodenotebookproblemsleetcode-solutions
progresivoJS/stanford-algorithms
Jun 2018 - Aug 2018
Contributions:19 commits, 8 pushes, 1 branch in 1 month
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