10 posts
An undergraduate thesis from 2019 — using a neural network (ANN) to predict PM2.5 concentrations 6/12 hours ahead. 94,225 observations from weather + air-quality data, AIC·VIF variable selection, Window Learning. Plus the time-lag pitfall discovered two years later.
7 implementation modules (Java) that show up repeatedly in Samsung-style simulation problems — 90° rotation, Periodic Boundary Condition (PBC), reverse direction, multi-condition sort, BFS, spiral coords, concurrent List remove. Plus 3 traps I fell into. Based on codetree / Baekjoon past problems.
Samsung Electronics coding test — 5 attempts across grad school (DX · Samsung Research) and post-employment (DX · DS · Device Platform). 4-hour simulation problems based on Baekjoon/codetree, Python/Java/C++ allowed. Each attempt failed differently: output format omission, language-switch trap, BFS over-engineering. Honest retrospective.
AWS Summit Seoul 2024 — walking the booths and sorting the trends into three buckets: generative-AI serving (chatbots, email, copilots, image-gen), multi-cloud CMP, and API gateway / middleware. 'Ideas converge — UX and performance is where companies actually win.'
Aug 5, 2019 — KAIST Mech Eng grad school written exam: 4 hours (2+2), 5 subjects, 5 problems per set. Set 1: terminal-velocity ODE, Von-Mises stress, rigid-body Work-Energy, Bernoulli+Energy equation, hydrostatic force on curved surface. Passed written, failed interview.
KAIST Mech Eng grad school written exam, Set 2 — Eigenvalue/Eigenvector (3-variable ODE system), full strength-design pipeline, rigid-body Work-Energy, T-v diagram thermo properties, Couette flow Navier-Stokes exact solution.
SK C&C (now SK AX) 2023 H2 new-grad recruitment — coding test (2h, 4 problems: sim, DP, sim, SQL aggregation) + SKCT in-depth (1.5h personality) + 1-day interview (group discussion + role/personality). Group discussion was actually fun and burned off the nerves before the role interview. Final offer.
Hyundai Motor 2023 H1 new-grad recruitment for CarCloud role — aptitude + AI interview (ViewInter, 12 questions) + coding test (Softeer, Java, 3 problems) + 1st interview (30-min pre-assignment + technical 1:3). Self-graded 4/6 well-answered; still rejected at the 1st round. Keyword recap: API Gateway, WebFlux, encryption.
LG Electronics 2022 H2 new-grad recruitment for R&D Campus in Gasan (H&A division) — coding test (Programmers, Java, 3 problems, two perfect + one partial) + aptitude + 1st interview (master's/PhD research presentation, 6-page PPT) + 2nd interview (executive + English OPIc) → final rejection. A case where job-role misalignment drove the result.
KT DS 2021 H2 new-grad recruitment — coding test (Programmers, 3 problems: Silver-4 stock sim, Silver-1 impl, Easy SQL) + aptitude + pre-assignment (1h, 1-page PPT) + 1-day interview (technical 4:1 + executive 2:N). Honest recap from a mechanical engineering + AI master's background with little IT experience.