How Long Does It Take to Build Custom AI Software?

7 min read
By Martin AnquetilLinkedIn

Martin Anquetil is a co-founder and managing partner of Lattice Partners, an AI implementation partner based in Los Angeles and New York.

On this page
  1. Short answer
  2. How long does it take to develop custom AI software?
  3. How long does it take to build an AI product end to end?
  4. What drives the timeline for custom AI software?
  5. How can we speed up a custom AI build?
  6. Is custom AI software worth it compared to buying a tool or an ERP module?
  7. How Lattice Partners does this
  8. Frequently asked questions

Short answer

Custom AI software usually reaches a working first version in weeks, and the full timeline depends on project type: days to a couple of weeks for a simple automation, a few weeks for an internal agent or integration, and several weeks to a few months for a full product. Lattice Partners is an AI implementation partner based in Los Angeles and New York that helps companies build an AI strategy, trains their teams on AI tools, and builds custom agents and software. Most custom AI products then go through 2 to 3 iterations based on real usage.

  • Data access, number of integrations, approvals, and number of iterations drive most of the schedule.
  • Waiting on access and decisions slows most projects more than the AI model does.

How long does it take to develop custom AI software?

Developing custom AI software takes anywhere from days to a few months, depending on what you're building and how many systems it touches. A narrow tool for one team on one data source ships fastest, and every added integration, user role, or approval step pushes the date out.

The table below shows typical timelines by project type for a first version people use on real work.

Project type Example Typical timeline to first version What usually sets the pace
Simple automation Pull data from incoming emails or PDFs into a spreadsheet, or draft a standard document from a template Days to a couple of weeks Getting sample inputs and agreeing on the output format
Internal AI agent connected to one or two systems An agent that drafts quotes from drawings and a material list, or answers questions from a CRM and a shared drive A few weeks Access to those systems and the owner's time to test
MCP integration Connecting Claude to a CRM like DealCloud, an internal database, or a data provider so the team can query and update it in plain language A few weeks API access, permissions, and which actions the AI is allowed to take
Full product build A scheduling or job-tracking system used across a company, with roles, dashboards, and several integrations Several weeks to a few months Number of integrations, user roles, approvals, and iterations

Timelines stretch when scope grows mid-build, so lock down what the first version does and park new requests for the next iteration.

How long does it take to build an AI product end to end?

Building an AI product end to end usually takes several weeks to a few months, counting discovery, the first version, and 2 to 3 rounds of iteration. The first version usually ships within a few weeks.

Most builds follow roughly this order.

  1. Discovery. Interview the people doing the work and confirm the use case, the data, and the owner.
  2. Scoping. Write down what the first version does, what it doesn't do, and how success gets measured.
  3. First version. Build against real systems and real data. Train the team on it.
  4. Iteration one. Fix what broke and cut features nobody uses, adjusting prompts and logic along the way.
  5. Iteration two and three. Add what users ask for once they rely on the tool.

"A small first version in a few weeks teaches you more than six months of planning. Having a real product in your hands helps you understand what you need."

Martin Anquetil, Co-Founder and Managing Partner, Lattice Partners

What drives the timeline for custom AI software?

Most of a custom AI software timeline comes down to data access, how many integrations there are, approvals, and how many iterations it takes. The AI model itself is rarely the bottleneck.

Data access. Data in a system with a usable API or export means work can start right away. Handwritten timesheets, scanned drawings, or someone's inbox are a different story, and the first job becomes getting that data into a form software can read.

Integrations. Each system the software reads from or writes to adds work: authentication, field mapping, error handling, and testing. Older systems such as some on-premise ERPs (enterprise resource planning systems) can take longer than modern cloud tools.

Approvals. Security reviews and legal sign-off on data use sit on the critical path, and so does any decision waiting on a busy executive. Name who approves what at the start and get time on their calendars.

Iterations. Most products need 2 to 3 iterations. Each one needs a few days to a couple of weeks of real usage before the feedback is worth acting on. A responsive owner keeps them short.

Scoping the first use case well shortens everything that follows. From AI strategy to production shows how.

How can we speed up a custom AI build?

To speed up a custom AI build, get access sorted before the work starts and keep the first version small.

  • Request system access, API keys, and test accounts in the first week.
  • Collect real examples of the inputs and the expected outputs (past quotes, sample reports, real emails).
  • Name one owner who will test each version within a day or two.
  • Put every "while you're at it" request on a list for the next iteration.

Slow builds often come down to waiting on access and decisions. Why AI pilots stall lists the common causes.

Is custom AI software worth it compared to buying a tool or an ERP module?

Custom AI software is worth it when your workflow is specific enough that off-the-shelf tools force you to change how you work, or when a vendor would charge a recurring fee for a module you'd use one way. When a standard tool fits, buy it.

ERP vendors such as NetSuite sell features like configure, price, quote (CPQ) as add-on modules. NetSuite's own CPQ page describes CPQ as "available as an add-on module" and says customers pay an annual license fee made up of the core platform, optional modules, and the number of users. A custom build is a one-time project, and the company owns the code. The tradeoff is that someone has to build it well and maintain it.

General writing and email are usually covered by tools like ChatGPT Enterprise, Claude, or Microsoft Copilot. Custom software earns its place when the workflow is unusual, as it often is at a fab shop or a private equity firm, and bending the process to an ERP module would fit worse.

To decide who builds it, see how to choose an AI consulting firm and what an AI builder is.

How Lattice Partners does this

Lattice Partners builds custom AI software for mid-market companies, often founder-led, in industries like private equity, finance, and manufacturing. The three founders are technical and write the code themselves.

We build internal AI agents, workflow automations, MCP integrations that connect assistants like Claude to CRMs, databases, and data sources, and full products like scheduling and job-tracking tools. An engagement runs in four phases: Learn, Tailor, Build and Ship, Iterate. When the project is well scoped, the first version usually ships within a few weeks, with hands-on training for the team. Most products then go through 2 to 3 iterations, and we can stay on after launch to support and improve what we built.

Custom software is a one-time build and the client owns the code. We don't charge a recurring per-seat or per-module license. Cost depends on scope.

Frequently asked questions

How fast can a first version of custom AI software ship?

A first version of custom AI software usually ships in weeks when the scope is one workflow and the data is reachable. Simple automations can ship in days. Full products with several integrations take longer to reach a first version.

Why do most AI products need 2 to 3 iterations?

AI products need 2 to 3 iterations because real usage surfaces edge cases, missing data, and requests that nobody predicted in scoping. The first version shows whether the workflow holds up, and later rounds make it reliable enough that the team stops working around it.

How much does custom AI software cost?

Custom AI software cost depends on scope. Simple automations cost the least, and a full product with several integrations costs the most. Lattice Partners scopes each project after learning how your team works, so we do not publish fixed prices. Contact us for a quote.

Who owns custom AI software after it's built?

Ownership depends on the contract, so check it before you sign. At Lattice Partners, custom software is a one-time build and the client owns the code. That means no recurring license fee from us to keep using it.

Can we build an MCP integration faster than a full product?

An MCP integration is usually faster than a full product because it connects an existing AI assistant to one system instead of building a new interface. Most MCP integrations reach a first version in a few weeks. Time goes into API access, permissions, and deciding which actions the AI can take.

About Lattice Partners

Lattice Partners is an AI implementation partner based in Los Angeles and New York. We help companies build an AI strategy, train their employees on AI tools like ChatGPT and Claude, and build custom AI agents and software. Clients own the code we build. Lattice Partners was founded by Colin McDonnell, Martin Anquetil, and Christian Yeghnazar. Contact us to talk about your use case.

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