Devesh JoshiCo-founder, product
Nine years building AI platforms serving 12,000+ engineers. LLM platforms, agentic systems (MCP), and multi-model safety evaluation.
Fixed price vs. milestone billing for agency work
The total is rarely what people are anxious about. It is when money leaves and what has to exist first.
Three structures, three different incentives
Fixed price moves all scope risk onto the agency, which sounds like your win until you notice what it does to their incentives. Every change becomes a negotiation, and the cheapest acceptable version of each feature becomes the rational choice.
Time and materials moves all of it onto you. It is honest about uncertainty and terrible at bounding it, because nothing in the structure rewards finishing.
Milestone billing splits the difference: a defined chunk, a fixed price for that chunk, and a decision point at the end of each one.
What makes a milestone real
A milestone tied to a date is a calendar entry. A milestone tied to a document is a status report. A milestone tied to something running is a milestone.
The test is whether you could refuse to pay it. If the deliverable is a demo you watched work, that judgement is available to you. If it is a percentage-complete figure, it is not.
How we bill
By milestone, on the sprint cadence. Each one is a working demo you have already seen — fourteen days to the first, fortnightly after that. Ongoing engagements bill monthly with thirty days notice in either direction.
You are never paying against a status report, and you are never more than a fortnight from the next point where stopping is a real option.
The question to ask any agency
Not “what is your rate.” Ask what has to exist before each invoice, and who decides whether it exists.
If the answer is a document, or the agency itself, you have learned the important thing about the engagement before signing anything.
Topic Focus & Target Concepts
This is the work behind our build practice — pitch-ready MVPs through to production applications, on a stack chosen for whoever maintains it after we leave.
Product and web app buildsRunning into this in your own stack? Twenty minutes, no deck.
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