One feature in your old codebase. Five working days. A fixed price.
For software houses and agencies with a client feature stuck in code nobody wants to touch. You pay half to book, and the balance only when the acceptance tests we agree on pass.
Why a transit company is doing this
You may know TechMavie Digital for Malaysia Transit, SG-JB Transit and Tour With Alan. Running live data for 18 transit providers (19M+ API requests so far), and building the feeds myself for operators that publish none, is daily practice in changing systems without breaking what already works.
That's the same job your clients' old systems need. And because the transit apps and API are free, paid work like this is what keeps them running.
I'm Aliff, based in Penang. I run TechMavie Digital and do the sprint work myself.
How the sprint works
A 30-minute call to pick one feature and check it fits in five days.
We write the acceptance tests together and fix the price before any code.
You pay RM1,750 to book a start date.
I build it on a branch with Claude Code, under the guardrails below.
You run the acceptance tests. If they pass, you pay the balance and keep everything. If they still fail at the end of the sprint, you don't pay the balance.
You get
- The feature on a branch or pull request
- Your existing tests still passing
- New tests for the feature
- Before-and-after numbers where they matter
- A short write-up of what changed and why
I need
- Access to the code and a way to run it
- Someone who can answer questions within a day
- JavaScript or TypeScript, or C++ (ask if your stack is different)
How I keep your code safe
Five rules, set before any code is written.
- Never change an existing format. New tables or fields, never a rewritten one.
- Never overwrite your data. Changes are additive, with a way back.
- One path for every action. New features go through your existing APIs and permission checks.
- Extras never touch the core. Cosmetic changes can't corrupt data.
- Done means measured. Acceptance tests and target numbers are agreed up front.
The proof: a C++ game over 20 years old
In under 24 hours, using Claude Code, I added a city-builder layer to OpenTTD, an open-source transport game first released over 20 years ago. It now has traffic lights and give-way rules, zoning, city services, numbered bus lines with departure boards, and streets full of cars and people.
- OpenTTD's own test suite
- 99 of passed after the first feature
- Old saves
- Versions 14.1 and 15.3, plus much older test saves, load, play, save and reload
- Unattended runs
- 5.5 game years with 30 buses: no crash, no gridlock
- Routing around jams
- Bus profit in the test town up 30%
- Cost, measured
- Town traffic adds about 0.06 ms per game tick
An independent fork, not affiliated with or endorsed by the OpenTTD project.
And a new app, from an empty folder
The same way of working is building MavieChat, a native iPhone app for three kinds of self-hosted AI server, written from scratch. Every change runs the tests plus two guards: one for code copied from the web apps it's modelled on, and one for copyleft packages.
See MavieChatCommon questions
Is the code written by AI?
Yes. Claude Code writes it under my direction, against the guardrails on this page and the acceptance tests we agree. You review the pull request like any other change.
What happens if the tests fail?
I keep fixing within the five days. If they still fail at the end of the sprint, you don't pay the balance.
Is our client's code safe with you?
I sign your NDA, and before we start I confirm in writing how my AI tools handle your code.
Who keeps the work?
Everything I deliver is yours to keep, change and ship.
What if the feature needs more than five days?
On the first call we find a slice that fits in five days, or I tell you it isn't a fit.
Is this separate from TechMavie's transit consultations?
Yes. The RM1,000 consultation is for transit and travel-tech projects. The Feature Sprint is delivery work for software houses and agencies, at a fixed price.
Why is there a founding price?
The first three sprints are RM3,500 while I build up client references. After that the price is RM5,000.
Have a feature you've been putting off?
Tell me what it is and which stack it's in, and I'll tell you whether it fits in five days.
Email me about a featurehello@mynameisaliff.co.uk