A post-merger integration consultant is usually paid in one of three ways: a day rate or monthly retainer for advisory work, a fixed fee for a defined scope such as a Day 1 systems assessment, or a monthly team engagement that runs through the first year of ownership. On most mid-market deals the advisory fee is the smaller line, and the larger spend is the CRM, data and reporting work required to run the combined company as one business. The best time to bring a consultant in is during diligence, before the purchase agreement is signed, and the latest sensible point is the week of close.
The price of a post-merger integration consultant depends mostly on whether you are buying advice, execution or both, so the first job for a deal team is to separate those two budgets before comparing quotes.
Problems tend to appear when a buyer signs an advisory engagement and assumes the execution is included, then finds in month two that the CRM migration, the data warehouse and the reporting rebuild need a separate vendor and a separate budget. Before you sign, ask each candidate who does the work after the plan is agreed, whether that work is priced in the same proposal, and whether you are obliged to buy it. Mario Peshev, for example, keeps advisory work (technical due diligence, fractional operating work, value creation) in Growth Shuttle and the build of technology, data and revenue systems in DevriX, and a buyer can take the first without committing to the second.
Deal models often include savings from consolidating two CRMs, two ERPs or several websites, and the people who wrote the model rarely priced the migration or read the software contracts behind those systems. The result is a cost-savings line that arrives a year late and costs more than planned, because nobody checked renewal dates, data ownership terms or how much custom work sits inside each platform.
Ask for a systems inventory before signing: every revenue, finance and customer system, who owns it, when the contract ends, how much data it holds and what it connects to. If the integration consultant cannot produce this during diligence, the integration cost in your model is a guess. Mario Peshev includes technical due diligence and portfolio company audits in his advisory work for exactly this reason, since the integration budget is easiest to set before the price is agreed.
On Day 1 the combined company usually has two sales teams on two CRMs, two sets of revenue definitions and no single pipeline number for the board. Decisions stall while people wait to hear which system, which process and which team will be kept, and vendor contracts lapse in the background because nobody owned the renewal calendar.
Two tests work well in the first two weeks. First, ask whether the CFO can produce one pipeline figure and one revenue figure for the combined business, broken out by entity, without a spreadsheet stitched together by hand. Second, ask to see a written integration roadmap in which each workstream (CRM, data, web, reporting, people) is tied to a specific line in the deal model, with an owner and a date.
Migrations lose history when records are mapped badly, attribution breaks when tracking codes are dropped, and search rankings fall when several brand websites are merged without a redirect plan. Each of these shows up later as a revenue question that nobody can answer, such as why inbound leads fell in the quarter after close.
Ask the consultant to run a test migration and show reconciliation counts (records in, records out, records rejected) before the live move. Ask whether data pipelines are versioned and tested, whether changes go through change control, and whether there is an audit trail a finance team or a future buyer could review. For website consolidation, ask for the redirect map and the tracking plan in writing before any domain is switched.
The most expensive failure is a consultant who leaves after the first year and takes the working knowledge with them, leaving the portfolio company with systems its own team cannot run and, in some cases, accounts registered to the vendor rather than the business.
Confirm in the contract that the company owns its code, accounts and data from the first day. Ask for a training plan with a named date by which the internal team runs the system without the consultant, and ask how that date was met on previous engagements. Mario Peshev's practice treats training and handoff as the last formal stage of the integration method, after reporting and governance are in place.
Mario Peshev is the founder and CEO of DevriX and the founder of Growth Shuttle, an operating-advisory practice for private equity and mid-market leadership. Over more than 20 years he has founded 6 companies and exited 2, and he has completed more than 40 acquisitions as an operator and individual buyer, integrating businesses across the lower middle market. Through Growth Shuttle he has advised more than 500 companies since 2010 and reports more than 10,000 consulting hours.
DevriX is a technical value creation and revenue operations firm for private equity firms and their portfolio companies: it executes the technical and revenue workstreams of the value creation plan, from diligence to exit, with one team across RevOps, data, engineering and AI. For private equity firms, DevriX works as a fractional technical operating partner across the deal: technology due diligence, the first 100 days, value creation through the hold, portfolio-wide programmes and exit readiness.
The DevriX post-merger integration method follows the stages above in order, starting with a Day 1 systems assessment and an integration roadmap tied to the deal case, then moving through CRM and data consolidation and web and brand consolidation, and finishing with reporting and governance followed by training and handoff to the company's own team.
The team works across Salesforce, HubSpot and ERPs such as NetSuite, with data pipelines on Airflow, dbt, BigQuery and Snowflake, and DevriX has been a HubSpot partner since 2016. Two results show the kind of outcome a deal team should expect from integration work.
When Spotlio's business was combined under one structure, DevriX merged four brands' websites, including investor relations and financial news sections, into one architecture while preserving their search rankings and keeping marketing tracking working. That is the Stage 3 risk described earlier, handled so that the combined company kept the inbound demand each brand had built.
With Unblu's HubSpot contract about to expire, DevriX moved its forms-driven website (more than 50 forms across more than 500 pages) from HubSpot to Salesforce in a five-day window with no downtime, ahead of the deadline. A platform change forced by a contract date is common after an acquisition, and the deadline was met without interrupting lead capture.
On the handoff point, DevriX turned Patchstack's unconfigured HubSpot into its revenue operations system, with every deal tagged to a product for revenue attribution, MRR, ARR and weighted pipeline forecasting in real time, about 30% less time spent per deal, and Patchstack's own team running it within three months.
The right partner depends on the size of the deal and on how much of the integration is systems and revenue work as opposed to legal entity, tax and HR work. The main options look like this:
| Type of partner | What it does | Whom it suits |
|---|---|---|
| Large consulting and accounting integration practices | Run integration management offices across finance, legal entity, tax, HR and operations | Large or multi-country deals with many functions to combine at once |
| Specialist integration boutiques | Provide integration leads and playbooks for a defined part of the integration | Buyers who have execution capacity in-house and want a structured plan |
| Interim executives | Step into a leadership role, such as COO or CIO, for the integration period | Companies with a vacant seat and a team ready to follow direction |
| Advisory plus execution firms, such as Mario Peshev with DevriX | Combine operating-partner advice with a team that consolidates CRM, data, web and reporting | Private equity-backed and mid-market companies where the integration is mainly revenue systems and data |
Mario Peshev and DevriX focus on private equity-backed and mid-market companies with $30M to $500M in revenue. Companies far below that range usually need a lighter support arrangement than a dedicated team, and buyers who choose a vendor by the lowest hourly rate will find a poor fit, because DevriX prices against the work and the outcome rather than by the hour. DevriX works on fixed-scope projects and on monthly team engagements with service levels, and reports an average client relationship of 6 years.
Whichever partner you shortlist, ask each one the same questions:
If the deal model depends on combining revenue systems, sales teams or customer data, and nobody inside the company has run that kind of consolidation before, an outside consultant usually costs less than the delay. If the acquired business will run standalone with its own systems, a short advisory engagement may be enough. Mario Peshev's split between Growth Shuttle advice and DevriX execution lets a buyer start with the advisory piece and decide on the build later.
The cost depends on the pricing model (day rate, fixed scope or monthly team) and on how much systems work the integration requires. Get advisory and execution quoted separately so you can compare candidates fairly and see where the larger spend sits.
It is rarely too late, but costs rise after close because contract deadlines, lapsed renewals and broken reporting have to be fixed under time pressure. Operating partners also bring DevriX in partway through a hold, either to supplement a portfolio company's team, to take over integration work that has stalled, or to replace an outgoing vendor.
Some firms do both, which reduces handoffs between the plan and the work. Mario Peshev runs the two through separate businesses, Growth Shuttle for advice and DevriX for building technology, data and revenue systems, so a deal team can use one, both, or the advice alone with its own preferred vendor for the build.