Implementation over spec
The technology is secondary. What decides the outcome is the quality of the build: finding the real problem, closing the edge cases, and finishing in a form that actually holds up in production.
Aconecto · registered software studio
Jongchan KoAconecto
How something is built matters more than what it's built with. Over ~5 years of shipping my own products, I've learned to find the real problem and carry it all the way to something that runs in production — end to end.
Taking on new projects for 2026 · I work in English, async across time zones, and usually reply within one business day.
- ~5 yrs full-stack
- craft over spec
- scope to release, solo
- ships, then keeps running
Aconecto business registrationA registered Korean software business since 2025
Information and communication · application software development and supplyFormal contracts, NDAs, and tax invoices available
Why Aconecto
Built to take the risk out of outsourcing
The stack is the easy part. The same spec ships very differently depending on how it's built — and that 'how' is where I do my best work.
One owner, end to end
Scope, design, frontend, mobile, backend, and release all sit with one person — no handoffs, no context lost between vendors, no finger-pointing.
Products, not just screens
Past the UI, I own the API contracts, data models, deployment paths, and testing — so what you launch is a working product, not a demo.
Safe, transparent to work with
A registered business with formal contracts, NDAs, and tax invoices — plus honest updates on scope, progress, and trade-offs, in English and on your schedule.
Selected work
Selected work
Client-sensitive details and real names are redacted. Each story focuses on the role I played, the shape of the delivery, and the technical depth — and the care taken with confidentiality here is itself a reference.
interface craft
Product-grade web interfaces with the details right
Dashboards, CRM and field-service tools, interactive sites, and admin products with UI that feels considered, not generic.
Smartcharge · dashboard + API
Smart Device Charging Compatibility Automation
An operator console and API workflow for smart-device charging-compatibility testing, with an information architecture built for fast comparison and faster decisions.
- Designed the operator console UX and information architecture
- Built the OpenAPI documentation flow
- Modeled the PostgreSQL data layer
Next.jsOpenAPIPostgreSQLDocker
device delivery
Mobile apps carried from first screen to the store
Rebrands, wearable flows, local builds, and release-ready apps shipped through TestFlight to the App Store.
VIV Ring · wearable app + backend
VIV Ring Intelligence Platform
A VIV smart-ring delivery spanning the iOS app architecture, NestJS API boundaries, local Swift packages, and a TestFlight-ready release path.
- Architected the smart-ring iOS app
- Drew the NestJS API and database boundaries
- Prepared iOS builds and packages for release
SwiftNestJSMySQLLiquibaseTestFlight
system depth
API, database, auth, and testing designed as one
Contract-first backends with a deployable structure that frontend and mobile can build against from day one.
NextPros · full-stack · live product
NextPros — Voice AI Back Office for Trades
A voice-AI back office for US plumbing and electrical trades that turns a single spoken sentence into a schedule, an invoice, and a follow-up. I built it end to end — web, mobile, backend, and cloud.
- Designed 247 gRPC endpoints from 13 proto definitions
- Shipped a Next.js admin and a Flutter app from one monorepo, in parallel
- Automated AWS deploys and CI/CD to cut release time
Next.jsKtorgRPCFlutterAWS
Specs
NextPros — Voice AI Back Office for Trades
One product flow tying a contract-first backend, multi-platform apps, and cloud delivery together — so field workers manage their schedule, customers, and invoices hands-free, by voice.
- Backend
- Kotlin·Ktor · 247 gRPC endpoints from 13 protos · MySQL
- Web·App
- Next.js admin dashboard · Flutter monorepo (multiple build targets)
- Cloud
- AWS Amplify·ECS deploy · GitHub Actions CI/CD
- AI workflow
- Voice-first interface · real-time gRPC streaming
- contract-first gRPC design
- parallel web and app delivery
- release automation that shortened deploys
release path
Cloud deployment and CI/CD that make launches calm
Container builds, cloud hosting, Git-based release flows, smoke tests, and the hardening that keeps launch day boring.
Backersby · mobile + payments + auto-deploy
Backersby — Creator Support Platform
A social crowdfunding app used by 1,000+ creators and 8,000+ supporters. I re-architected it from a tangled legacy codebase into clean architecture, with payments, real-time features, and automated store releases.
- Migrated GetX to Riverpod clean architecture across 35 screens
- Built Toss payments, real-time chat, and FCM push
- Set up Fastlane + GitHub Actions for store auto-deploy
FlutterRiverpodRESTWebSocketCI/CD
agentic workflow
AI-assisted build, review, QA, and documentation
Agentic workflows that speed up delivery without giving up traceability or human judgment.
AI-native delivery
An agent workflow across build, review, QA, and docs
Multi-agent tooling like Claude Code, Codex, and Gemini speeds up delivery, while review evidence, tests, and human judgment stay firmly in the loop.
multi-agentcode reviewautomated QAdocumentation
Personal apps
Apps I shipped solo
Products I scoped, designed, built, and shipped end-to-end — App Store releases, a Mac utility, and a production web learning service.
FormLab
An AI coach that reads your squat form in real time, straight from the camera
Haru Maeum
An emotion journal that on-device AI (Gemma) quietly summarizes for you
Your Spine Is Screaming
A Mac menu-bar nudge that gets long sitters back on their feet
Sweat Quiz
A web quiz service for Korean sports instructor oral-exam prep, with progress, review, and paid access flows
system ownership
Ownership past the screen
Not just screens. I own the API contracts, data models, deployment paths, and testing loops — the structure that has to hold up long after launch.
API contracts
OpenAPI, gRPC, and REST contracts defined first, so web and mobile can build in parallel without guessing.
- endpoint map
- schema review
- typed client handoff
Data and security
PostgreSQL models, access boundaries, and safe handling of sensitive data, designed together rather than bolted on.
- schema draft
- access rules
- privacy scan
Release hardening
Container builds, CI, QA checklists, and smoke tests that cut launch risk before anything ships.
- build pipeline
- release checklist
- rollback notes
How I work
From a vague idea to a plan you can ship
From the first message to handoff, the work moves through clear, predictable steps.
Diagnose
We line up goals, timeline, budget, and what already exists. Then I propose a realistic scope and schedule — honestly, even when the honest answer is 'smaller'.
Design
We agree on screens, API contracts, and data models up front, so frontend and backend can move in parallel without surprises later.
Build
AI-assisted workflows keep delivery fast, while code review and QA evidence keep quality visible at every step.
Hand off
You get the deployment paths, a release checklist, and the documentation you need to run it — so you're never locked in.
freelance models
Ways we can work together
From a fresh MVP to rescuing a stalled codebase — senior ownership that carries the work all the way through.
MVP build
A lean web, app, and API build, focused enough to reach real users — and real feedback — fast.
- product scope
- interactive UI
- deployable backend
Frontend systems
Dashboards, admin tools, and product sites built for the people who use them every day.
- design system
- responsive screens
- interaction QA
Technical rescue
Broken QA, stalled releases, and tangled API contracts, untangled and stabilized — so a stuck team can move again.
- bug triage
- test coverage
- release recovery
Pricing · how we engage
Start in the format that fits your project
Every engagement is quoted by scope and timeline. These are the formats I use most.
Fixed scope · fixed quote
Project package
MVPs and new products with a clear launch goal
- scope and timeline locked in the quote
- delivery from scope to launch
- release checklist and handoff docs
Weekly contract · flexible scope
Weekly retainer
Live products that need steady improvement
- priorities agreed each week
- flexible feature and fix work
- regular progress updates
Short, focused diagnosis
Tech audit · rescue
Stalled or shaky codebases
- code, deploy, and QA review
- a risk report
- a roadmap back to shippable
Instead of a fixed rate card, the first conversation looks at scope, timeline, and budget together — then I send a realistic, written quote.
FAQ
What clients ask before we start
Can you sign formal contracts and issue tax invoices?
Yes. Aconecto is a Korean software business registered since 2025, so I can sign formal contracts, issue tax invoices, and work under an NDA whenever you need one.
How long do projects usually take?
It depends on scope, but most MVPs are measured in weeks, not months. I'll map a realistic timeline in our first conversation, before you commit to anything.
Can you take over a stalled project or existing code?
Yes. I start with an audit of the code, deployment, and QA to lay out the risks and the rescue scope, then focus on getting it back to a shippable state.
How much of the work can you own?
Scope, design, frontend, mobile, backend, and release can all sit with one person. Hand over the whole build, or just the part you're missing.
How do you handle confidentiality and security?
Exactly like this portfolio: sensitive details are fully redacted. Client information and operational data are never exposed, and confidentiality is the default, NDA or not.
How does communication work across time zones?
I work in English and async, so the time-zone gap is rarely a problem. I usually reply within one business day and share progress and decision points on a regular cadence, in whatever channel you prefer.
contact
Tell me about your project
Share the project type, timeline, target platform, and anything you already have. I'll reply with a clear, honest next step.
jongchanko@gmail.com
- project type
- target timeline
- web / app / backend scope
- what you already have
Next step
Want one person to carry your product all the way to launch?
A rough idea or a stalled project — either works. I'll start by mapping out a realistic direction, and you'll hear back within one business day.
Start a project