I work in Next.js and Supabase, covering requirements, database design, implementation, deployment and incident response. Explore the implementation details of selected products. Available for contract and advisory work.
My time is currently taken up by the products I run. From January 2027 I can take on new work, starting at around two days a week. A conversation now about a later start is completely fine.
Availability last updated: September 15, 2026
I work on a monthly retainer based on days per week. The real number depends on scope and length, but these are the starting points. For fixed-scope project work, see the Services page instead.
Design review, code review, technical direction, and small ongoing changes.
Owning part of a product and shipping features continuously.
Core member on an early-stage product, from design through production.
Technical direction, architecture review, or a look at an existing codebase. A single session with no commitment is fine.
This list covers the technologies used in the products below.
You can carve out a narrower slice, but covering the whole path is where I am most useful. Fewer people in between means less time between deciding something and seeing it live.
Explore their implementation details.
Sole developer — concept, design, build, operations
A discovery platform matching visitors to Japan with nail salons in Tokyo. Implemented Sumi, a rule-based guide that suggests salons based on preferences and styles.
Sole developer and technical lead
Status tracking from signup through screening, trial visit, contract and go-live, with automated email keyed off the confirmed date. Includes the operator admin and permission model.
Sole developer — concept, design, build, operations
Implemented AI handling of LINE enquiries, availability checks, reservation proposals and booking confirmation after customer approval. Built as per-industry plugins.
Tell me where the product is and what is in the way. If I am not the right fit, I will say so.
Send any time — I reply within 1 business day.
By email: info@shingokumon.com. Project pricing is on /en/services.
Availability last updated: September 15, 2026