01
MVP builds
Idea to a deployed product your users can sign into. Auth, payments, dashboards, admin and infrastructure: the unglamorous parts that decide whether it works.
6–8 WEEKSFIXED SCOPE
FULL-STACK ENGINEER · 5 YEARS IN BLOCKCHAIN, FINTECH, AGENCY
Your product,built by the personwho understands it.
● 2 SLOTS, Q4 2026GMT+8 · OVERLAPS EU & APACMONARKSTENCILCLASSPORTALSCROLL_
What I build
01 / SERVICES02
Backend & APIs
Data modelling, services, queues, third-party integration. Systems that survive their second year and the load you didn't plan for.
POSTGRESNODE · GO
03
Web3 integration
Contract integration, indexers, wallet flows and custody-adjacent plumbing, from someone who has shipped them with real money on the line.
EVMINDEXERS
04
Contract capacity
Embedded with your team or your agency's, by the month. Work off your board or a written brief, and get shipped features back. White-label if you need it.
MONTHLYWHITE-LABEL
You don't need to arrive with designs. Dashboards, admin panels and product UI I lay out cleanly myself, from a brief or a rough sketch. If you already have a designer or a brand system, I'll build to it exactly.
Selected work
02 / CASE STUDIES01PERSONAL FINANCE · 2025
Monark
A money management app. Multi-account budgets, categorised transactions and a ledger that reconciles. The accounting model is the hard part, not the charts.
NEXT.JSPOSTGRESDOUBLE-ENTRY LEDGER
monark-seven.vercel.app ↗monark-seven.vercel.app
02STUDIO OPERATIONS · 2025
Stencil
Management software for tattoo studios. Artist calendars, client bookings, deposits and consent paperwork in one place, built around how a studio actually runs its day.
SCHEDULINGPAYMENTSMULTI-TENANT
stencilapp.art ↗stencilapp.art
03EDUCATION · 2026
Classportal
Tutor and student management for a tutoring business. Scheduling, attendance, progress notes and invoicing, replacing a spreadsheet stack that had stopped scaling.
ROLES & PERMISSIONSINVOICING
classportal-dev.vercel.app ↗classportal-dev.vercel.app
010203
SCROLL →
THE PROBLEM
Most MVPs don't die from bad code. They die in the gaps.
Between the designer and the developer. Between the developer and the deploy. Between the account manager and the person actually writing it. Every handoff costs a week you didn't budget.
KEEP SCROLLING↑
How we'd work
03 / PROCESSSTEP 01 · FREE
Scope call
Thirty minutes. What you're building, who it's for, what already exists. You leave knowing whether I'm the right fit.
STEP 02 · WEEK 1
Technical plan
Data model, architecture, third-party choices and a scoped build plan with a fixed price. Yours to keep either way.
STEP 03 · WEEKLY
Build in slices
A working deploy every week, not a demo at the end. You use it as it grows and redirect while it's still cheap to redirect.
STEP 04
Hardening pass
Auth, access control, input handling, secrets and rate limits reviewed the way I'd attack them. Included, not an upsell.
STEP 05
Handover
Your repos, your infrastructure, documented. Thirty days of support after launch, then a retainer only if you want one.
- LANGUAGES
- TypeScript
- Go
- Python
- Solidity
- BACKEND
- Node · NestJS
- Express
- REST · GraphQL
- Queues · Workers
- FRONTEND
- React · Next.js
- Tailwind
- GSAP
- three.js
- DATA
- PostgreSQL
- Redis
- Prisma
- ClickHouse
- INFRA
- AWS · GCP
- Docker
- CI/CD
- Observability
- SECURITY
- Threat modelling
- Access control
- Contract review
- CTF background
BALI · GMT+8
Christopher
Yu
Yu
About
04 / BACKGROUNDI'm Christopher. I build web products end to end: the database, the API, the dashboard, the deploy.
Five years across three very different rooms: a blockchain company where mistakes are expensive and public, a fintech where the ledger has to balance every time, and a digital agency where the deadline is the deadline. Different constraints, same job: make the thing work.
Before that I played CTF competitively. Strange hobby, but it turned out to be useful: I spent years looking for the ways software breaks, so I write it differently. Security review happens while the code is written, not in an audit six months later.
- 5
- years in production engineering
- 3
- industries: chain, fintech, agency
- 1
- engineer, end to end
2021 — 2022Blockchain companyContract integration, indexing and wallet-facing services with real value at stake.
2022 — 2024FintechPayments, ledgers and reconciliation. Correctness under load, with regulators reading over your shoulder.
2024 — NOWDigital agencyClient products on fixed timelines, shipping alongside designers, PMs and other people's codebases.
Engagements
05 / PRICINGFixed prices, not hourly. You know the number before the work starts, and it doesn't move unless the scope does. For comparison, agencies quote a build of this scope at $15,000–60,000.
FOUNDING-CLIENT PRICINGThe first three projects, held through Q1 2027.
AUDIT
$900FIXED
Three or four days. I read the codebase, or the brief, and hand back what's broken, what it costs to fix and what I'd do first.
Architecture & security reviewFindings written up, in priority orderCredited against a build
TECHNICAL PLAN
$2,400FIXED
One week. Data model, architecture, build plan and a fixed quote for the build. Credited back if you go ahead.
Architecture & data modelScope, risks and sequencingFixed quote for the build
RECOMMENDED
MVP BUILD
from$9,800
Six to eight weeks, fixed scope and fixed price. A deployed product, your repos, your infrastructure.
Weekly deploys you can useSecurity hardening pass included30 days post-launch support
EMBEDDED
$5,200/ MONTH
Dedicated capacity in your team or your agency's. Minimum one month, two weeks' notice to stop.
Your board, your standupsWhite-label for agenciesEU & UK morning overlap
Multiple user roles, money movement, multi-tenancy or a migration from an existing system move the number. The plan says by how much.
Prices in USD. Builds are 40% to start and the remainder on delivery; retainers are invoiced monthly in advance. A rescue or a single integration is quoted flat after the scope call.
github.com/ChaO-0● LIVE
VIEW PROFILE ↗216 ACTIVE DAYS, LAST 12 MONTHSLESSMORE
● TAKING WORK FOR Q4 2026 · 2 SLOTS
Tell me what you're building.
Thirty minutes, no pitch deck. If it isn't a fit I'll tell you on the call and point you somewhere better.
OR EMAIL: CHRISTOPHERYUU8@GMAIL.COM