Services · From idea to product
When you have the idea
but no one to build it.
With 14+ years in QA plus full-stack building, from MVP to launch - I work alongside you. I prefer to work as a partner, not a vendor. We decide what to build together, starting from the brief.
Mon-Fri 10:00-19:00 KST · Replies usually within 1 business day.
What I can help with
Who this is for.
MVP 0 → 1
From idea to a shape your first users can touch. Before building, we settle what to build - and what not to.
Best fit
You have a one-line hypothesis and don't know where to start.
The next step for a service in market
You have a site or app running but "how do we grow this?" is stuck. We lock in prioritization, experiments, and release decisions together.
Best fit
A solo operator whose decisions got heavier as the traffic grew.
QA / release setup
For teams where pre-release incidents keep recurring or who need regression-test automation - Playwright / Pytest setup and the workflow to keep it running.
Best fit
Teams too small to hire a dedicated QA engineer.
How it works
How we work together.
- 01
One-page brief
Send goals, current state, and timeline/budget on a single page to hello@hongjae.co. I review and reply.
- 02
Scope and timeline proposal
A one-page proposal: what we'll build, what we won't, how much, and by when. All the information needed for a decision on one screen.
- 03
Weekly build → demo
Weekly demo and decision meeting. Decisions get a trace, and we set next week's priorities together.
Brief template
One-page brief template.
It doesn't need to be precise. Empty slots are fine - fill what you can. Paste the template into your email and reply inline.
- · Estimates and timeline replies usually within 1-2 business days.
- · Prices are not listed publicly; I reply with a range based on the brief.
- · If we're not a fit, I'll say so honestly - and may point you to a builder who is.
One-page brief template
1. One-line summary (This product/service in one line) 2. Who uses it (Target user, rough scale) 3. Problem to solve (The friction or inefficiency users hit today) 4. What's been done (What's already built, what was tried, what didn't work) 5. Definition of success (One paragraph on what "success" looks like 8-12 weeks from now) 6. Timeline (Hard deadline if any, otherwise "flexible") 7. Budget range (Doesn't need to be precise - rough band is fine) 8. Decision maker (Yourself or someone else - who signs off) 9. References (URLs, screenshots, competitor services, etc.) -- 강홍재 Hongjae Kang (James) hello@hongjae.co 010-8487-6861 hongjae.co
Honest scoping
When we're not a fit.
- Strongly regulated domains like healthcare or finance - the risk structure doesn't fit a solo builder's accountability.
- “Just build it” arrangements - I can't stand behind the result if I'm not in the decisions.
- Timelines that require shipping a full-spec product without user validation - I recommend MVP → validation → expansion instead.
Also (side gigs)
Small units I can take on alongside.
The main work is the building / QA above. I also take on small, clearly scoped pieces. For design studios or brand consulting, I'd point you to someone whose main work that is.
- Instagram cards / single SNS graphics (when requirements and copy are provided)
- A single static landing page (copy and images provided)
- Logo, color, and font cleanup kit (organizing assets that already exist)
- Defined units that wrap in 1-2 days
Start with the one-page brief.
Even one line is enough. Send goals, current state, and timeline/budget on one page, and we'll figure out together whether it's worth building.