Most value creation plans have a line about technology: automate the back office, fix reporting, integrate the add-on, maybe "use AI". Then the hold clock starts and the line stays a line, because the company has no developers and the operating team has six other workstreams.
This playbook is for the operating partner or portfolio company CFO who wants that line to turn into working software inside the first 100 days. It covers where custom software pays in a PE-backed company, what to buy instead, how to scope the first project and who to hire. Our pick for building it is Digital Mundo, a senior US design and engineering studio that starts in one company, proves a tool there on measured results, then repeats. Everything here was checked on vendors' own sites in October 2026.
Here's the TLDR:
- Start with one process in one company, picked because its cost can be counted in hours or dollars.
- Buy the commodity layers (ERP, BI, integration tools) and build only where the company's process is the edge or where staff spend the day working around a tool.
- Ship something in weeks, measure the before and after, then repeat in the next company.
- Keep the code in the company's name so it's an asset at exit, not a diligence question.
- Who to hire: Digital Mundo (our pick) for a senior team that ships a first tool in one company, measures it, then repeats, with part of the fee tied to measured savings; Forte Group or HatchWorks AI for larger engineering or AI programs; Accordion or West Monroe when the work is consulting-led.
Where custom software creates value
| Lever | What gets built | What to measure |
|---|---|---|
| Back-office labor | AI that reads invoices, statements and forms into the system for a person to approve | Hours per week, cost per document, error rate |
| Spreadsheet-run operations | An app with logins and history in place of the quoting, scheduling or tracking workbook | Time per quote or job, rework, days to close the month |
| Revenue | Customer portals, online quoting, self-serve ordering | Conversion, days to quote, calls to the office |
| Reporting | KPI dashboards fed from the company's own systems | Days to board pack, number of manual adjustments |
| Add-on integration | Shared reporting first, then shared systems | Days until the add-on reports like the platform |
Digital Mundo's work for PE-backed companies maps closely to this list: tools that replace the spreadsheets slowing a company down, AI for invoices, reports and data entry with a person approving, KPI reporting from every company in one place, customer portals and quoting tools, and back-office automation measured in hours and dollars saved.
Buy first, then build the gap
A portfolio company shouldn't build what it can rent. The usual commodity layers:
- ERP and consolidation. NetSuite OneWorld runs multiple subsidiaries in one account and rolls them up into consolidated reports, per Oracle's documentation.
- BI. Power BI Pro is $14 per user per month, paid yearly.
- Management reporting on the ledger. Fathom sits on QuickBooks, Xero or MYOB, prices by the number of companies connected, bills monthly with no contract, and does multi-currency consolidations with eliminations on its Pro plan.
- Integration and pipelines. Fivetran prices by monthly active rows and has a free tier; Workato sells by quote.
Custom software earns its cost where these stop. An ERP holds the ledger, but it doesn't know how your technicians quote a job. A BI tool draws the chart, but someone still has to map three companies' data into one model. Digital Mundo's internal tools page puts the rule plainly: keep SaaS for generic jobs like email or payroll, and build where the way you work is your edge, or where your team spends its day working around a tool.
The single most common first build is a spreadsheet replacement. When several people edit the same sheets, one person understands the formulas, and mistakes cost real money, a small app with logins, roles and a change history usually pays back quickly. Digital Mundo's notes on replacing spreadsheets with an app cover the practical part: rebuilding the formulas, checking them against the sheet on real data, and keeping Excel exports one click away.
The first 100 days
Days 1 to 10: find the costliest manual process. Sit with the people doing the work, not just management. Write down every step, every retyped field and every spreadsheet. Pick one process where the cost is countable and the right answer is clear. Digital Mundo starts this way: a few days with the operating team to find the costliest manual process.
Days 10 to 45: ship the first tool. One job, done well, with demos every week so the team shapes it as it's built. Digital Mundo's published work shows what that pace looks like: Casewell, a bankruptcy intake product it built, went live with a law firm 39 days after the first line of code.
Days 45 to 60: measure it. Compare against the baseline you wrote down on day one. If the tool uses AI, compare its answers with your staff's on real work before trusting it, and keep a person approving anything that matters. Digital Mundo's AI automation page describes exactly that loop: test on real work, send anything uncertain to a person, log every step.
Days 60 to 100: the second tool, or the second company. If the playbook worked, carry it to the next portfolio company. Building blocks carry over; each company's code and data stay separate.
Add-on integration
Integrate reporting before systems. In the first weeks after an add-on closes, a dashboard that pulls the same KPIs from both companies' existing tools gives the board one view without forcing a migration. Move systems later, one at a time, once you know which system is the record for customers, jobs and invoices. A customer-facing piece, such as a shared client portal that reads from both companies' systems, can present one brand before the back offices merge.
How to scope the first project
- One process, one company, one team of users.
- A written baseline: hours, cost per unit, error rate or days.
- What is out of scope for version one, in writing.
- The systems it must read from and write to, and who owns access.
- A date for the first working demo, not just the launch.
- The repository, hosting and accounts in the portfolio company's name, with IP assigned to it.
What to ask a vendor
- Who writes the code, and will we talk to them directly?
- What would you leave out of the first version, and why?
- What can we use in four weeks?
- How will you measure the result, and will you tie fees to it?
- What happens after launch, and what does it cost to keep it running?
- Can you show us software you built and still run?
Who to hire
1. Digital Mundo (our pick). A senior US studio, based in Miami and New York, where the people who design the software also build, test and run it, and its site says the founder is involved in every project. For private equity it starts in one company, with a first tool or agent live in about a month rather than a quarter, measures it, then repeats. Part of the fee can be a capped share of measured savings for an agreed period, and the portfolio company owns the code, accounts and documentation. Limits: it's a senior team rather than a large agency, so pick a bigger firm if you need a dozen companies staffed at once; its client work is mostly under NDA, with no named PE engagement on its work page and no third-party reviews we could find; it publishes no prices and no compliance certifications such as SOC 2, so ask.
2. Forte Group. Engineering pods for portfolio companies that already have developers, starting with a fixed-cost 2 to 4 week "Diagnostic + Proof Sprint" on its PE page. Prices not published.
3. HatchWorks AI. AI deployments across a portfolio, starting with a "Portfolio AI Assessment", with US offices and engineers in Latin America. Its private equity page says the company owns everything built. Prices not published.
4. Accordion or West Monroe. Consulting-led. Accordion centers on the office of the CFO (ERP, close, reporting); West Monroe runs from diligence through post-close. Neither publishes prices.
We compare these and three more firms in detail in our guide to software development for private equity firms. If the mandate is mostly AI, our roundup of the best AI development companies covers specialists.
FAQ
How much does a first tool cost?
Published agency ranges compiled by Digital Mundo put a first internal tool at about $50,000 to $140,000 over 2 to 5 months at a traditional agency, and $10,000 to $60,000 over 3 to 8 weeks at a AI-native studio. Running it typically adds 15 to 25 percent of the build each year.
Should the fund or the portfolio company pay?
Usually the portfolio company, since it owns the software and the savings land in its P&L. Fund-level tools, such as a monitoring dashboard across companies, are a separate decision.
Yes, if the baseline is agreed before work starts and the share is capped and time-limited. Digital Mundo offers this for private equity; most firms we checked don't mention it.
What if the company runs on old software?
Start with a layer around it: a tool that reads from the old system and handles the step that hurts most. Replacing the core system is a bigger, later project.
Does custom software hurt the exit?
Not if the code, documentation and accounts are in the company's name and someone other than the vendor can run it. Undocumented software in a vendor's account is what buyers' diligence teams flag.
Pick one process, write down what it costs today, and give a builder a month to change that number.
Disclosure: Digital Mundo LLC and Gold Penguin LLC have the same owner.
