a softboi backend engineer序章 · origin
Wilbert
Nadar— 一歩ずつ. one step at a time.
Computer Engineering undergrad. ex-SDE intern @ Aruya Tech. I poke systems until they tell me their secrets — and lately they've been telling me a lot.
view from the 8:42 — bio.txt
I love diving deep into how systems actually work. Big fan of cracking hard problems — the messier the puzzle, the better. Currently shipping a code judge that doesn't fall over, and racing my own LeetCode rating.
600+
problems solved
1.18s
avg judge exec
99%
stress-test pass
297
best contest rank
scroll · the sky's going somewhere
Ch.02The Build
things I shipped創
one is online, one is alive. the rest live on my hard drive — for now.
EP.01 · Dec 2025
Online Code Judge
Java · Spring Boot · Docker · PostgreSQL · React
OFFLINE
58%
speedup
1.18s
exec time
50req
concurrent
99%
reliability
A full-stack competitive programming platform with a containerized execution engine — built to run untrusted code safely, fast, and at concurrency, on a budget VM.
- Designed and deployed a containerized code execution engine for secure, isolated runs on a 4GB / 1 vCPU VM.
- Pre-warmed Docker container pool (5–10) — cold-start gone, avg exec time dropped 2–3s → 1.18s (≈58% faster).
- Producer–consumer architecture on Java BlockingQueue: 30–50 concurrent requests, zero crashes, zero data races.
- Google OAuth2 sign-in + RBAC for clean multi-user separation.
- 99%+ reliability across automated stress-test batches.
producer → queue → pool · architecture
JavaSpring BootDockerPostgreSQLReact.jsBlockingQueueOAuth2RBAC
Ch.03The Climb
i like hard problems登
600+ problems across three platforms. the ratings climb. the bugs cry. the queue empties.
rating.trajectory()
LeetCodeCodeChefCodeforces
LeetCode
solved450+
note8 contests · still climbing
CodeChef
solved120+
notepeak 1550 · rank 297 in rated
Codeforces
solved30+
notePupil — climbing since Sep '25
600+
total solved
3
platforms active
297
peak contest rank
∞
dopamine hits
Ch.04Waypoints
cat ~/history.log途
a few stations along the way. some scheduled, some unscheduled.
Dec 2025 — now
Online Code Judge
@ personal · production-ish
Built and deployed a full-stack judge that survives concurrent abuse. Container pools, BlockingQueue, OAuth2, RBAC, and a lot of staring at htop.
Mar 2026 — Apr 2026
SDE Intern
@ Aruya Tech
Shipped backend features on Java + Spring. Learned what production traffic feels like when your tests pass and reality disagrees.
Nov 2024 — now
the CP grind
@ LeetCode · Codeforces · CodeChef
600+ problems and counting. Past 1600 on LeetCode, past 1550 on CodeChef, climbing on Codeforces. Rank 297 in a rated contest. Currently negotiating peace terms with hard problems.
ongoing
Computer Engineering, Undergrad
@ in progress
Systems, networks, OS, the works. Mostly there to learn what the libraries are hiding from me.
Ch.05Inventory
tools of the trade技
stack i reach for. always learning the next one.
languages
- Java
- C++
- C
- JavaScript
- Python
frameworks
- Spring Boot
- React.js
- Redux
- FastAPI
tools
- Docker
- Git
- GitHub
- Linux
- PostgreSQL
concepts
- DSA
- OOP
- REST APIs
- Concurrency
- Multithreading
- Producer-Consumer
- Containerization
- System Design