Last updated: October 26, 2026
By Kris Drouet, Engineering Executive, in partnership with KORE1
When acquired engineers leave after retention cliffs pass, backfill bounded work with contract engineers while the permanent org settles, and keep architecture, customer-facing ownership, and audit-facing work with employees. KORE1-placed software engineers bill $91 to $120 an hour, median $105, and the median KORE1 contract assignment lasts 116 days (n=1,887).
Here’s a Monday I’ve sat through more than once.
The retention payout cleared on Friday. By Wednesday, two of the five engineers who understood the acquired billing service had given notice, a third was “thinking about it,” and the VP of Engineering was staring at an integration plan with a cutover date the board had already heard out loud. Nobody did anything wrong. The money did exactly what it was designed to do, which was hold people until a date. The date passed. Sound familiar?
If that’s your calendar right now, this piece is about the next 90 days. It isn’t a retention playbook. I covered how to keep people in a 100-day plan for merging two engineering orgs, and the inherited-team diagnosis in inheriting an engineering team you did not hire still applies. This one starts after some of them have already gone. The question is how you hold the integration dates with the people you have left plus contract staffing for the work that can safely move.
One thing before we start, because I’d want to know it if I were reading. KORE1 sells contract engineers, and I write in partnership with them. Part of this post says when you shouldn’t buy any.
Why Do Acquired Engineers Leave Around Month Four?
Most leave when a retention cliff passes and the first honest look at the combined company is done, which in the deals I’ve worked lands somewhere between month three and month six.
The mechanism is boring. A retention bonus pays in tranches. Each tranche is a date on a calendar, and each one tells the engineer exactly when staying stops being a financial decision and becomes a personal one. Layer on a reorg announcement that arrives right around then, a title that didn’t survive the org chart redraw, a new manager they’ve met exactly twice, and a Slack channel that went quiet the day the old CEO’s name came off the all-hands invite, and you’ve built a very precise alarm clock. Everyone’s alarm goes off in the same week. Not by coincidence. By design.
You won’t find an attrition percentage here. Honestly, I don’t trust the ones I could quote. The good studies are academic, a decade or more old, and drawn from pharma and semiconductor deals, so mapping them onto your sixty-person SaaS team would be a guess dressed up as a statistic. The 100-day post has the research if you want to judge for yourself. My own read, for what it’s worth: the first ones out are the engineers with options. Rarely the ones you’d have picked to lose.
What Breaks If Integration Milestones Slip?
Before KORE1 partner Devin Hornick scopes anything like this, he asks, “What breaks if the company doesn’t spend the money or finish the project?” Most integration plans I’ve read can’t answer that in a sentence.
Try it on yours. Pull the milestones from now to the end of the transition services agreement and put one line next to each. Revenue, customers, audit calendar. Which of those moves if the date slips ninety days?
For a lot of them, nothing. A tooling consolidation that slips a quarter costs a second observability bill and some grumbling. For the rest, plenty. Slip the billing cutover and you’re running two ledgers through a quarter close, with a controller who has stopped returning your calls. Slip a security remediation you promised a lender and it becomes a finding in somebody else’s report. Slip the feature the deal thesis was priced on, and finance opens a spreadsheet you’d rather they didn’t.
Sort the milestones into those two piles before you hire anyone. Show me the data, as I tend to say, and by data I mean the dated commitments and the person each one is attached to. The ones attached to someone who just resigned are your bridge candidates, while the ones attached to a decision rather than a deliverable are not, which matters because a decision can’t be handed to a person whose contract visibly ends in four months. More on that below.
Which Work Can a Contractor Backfill, and Which Stays With Employees?
The test I use has two halves. Is the work bounded, meaning a written interface, a definition of done, and a reviewer? And does the knowledge live in the code rather than in the departing person’s head? When both are yes, a contractor can usually carry it. When either is no, you’re asking a stranger to guess. Don’t.
| Type of work | Contractor backfill or employee only | Why |
|---|---|---|
| Feature work inside a service with tests and documented interfaces | Contractor backfill OK | The tests already say what done means. Ramp-up is weeks, not quarters. |
| Integration seams, such as an API or event contract between the two systems | Contractor builds, an employee owns the contract | The build is bounded. The decision about what crosses the line is not. |
| Test automation and regression coverage for the acquired product | Contractor backfill OK | Output is easy to review, and it protects the next cutover. |
| Data migration scripts and cutover rehearsals | Contractor builds, an employee signs off the cutover | Scripting is mechanical. Choosing the go or no-go belongs to someone with a badge and a boss. |
| Runbook and documentation capture from people who are leaving | Contractor OK, but only before the exit date | A contractor reconstructing a runbook after the author leaves is guessing. Beforehand, it’s capture. |
| On-call rotation seats | Contractor can hold a seat, an employee owns escalation | Someone with rollback authority has to be reachable at 2 a.m. |
| Architecture and other one-way-door decisions | Employee only | The person who lives with the answer should make it. |
| Customer-facing ownership and escalations | Employee only | Customers are buying continuity. A rotating cast signals the opposite. |
| Security approvals, access reviews, and anything an auditor will ask about | Employee only | Control owners are accountable people. A contractor can do the work, but the signature stays inside. |
| Hiring, leveling, and performance decisions | Employee only | Not a close call. |
One note on the audit row, since it surprises people. Frameworks like NIST SP 800-53 Rev. 5 have a control family just for external personnel security (PS-7), which asks you to set requirements for outside providers, document them, and monitor compliance. Contractors are fine. Contractors you can’t account for are the finding.
Hold the integration date. If two or three rows of that table describe what just walked out the door, request a bridge team and tell us four things: the roles that are leaving, the milestone dates they carry, the start date you need, and how long you expect the gap to last.
Want the numbers first? The 2026 contract rate card has the bill ranges, and how the Contract Rate Index is built explains where each figure comes from.
Which Roles Should You Never Backfill With a Contractor?
The principal engineer who holds the design of the acquired platform in their head. The tech lead who decides what the team works on this sprint. The incident commander. The owner of any control an auditor tests. The technical owner on the biggest revenue account. Five seats. None of them is a staffing problem.
I’m stubborn about this because I’ve watched the alternative. When the person who carries a decision leaves, there’s a strong temptation to hand the whole chair to the first competent senior engineer who shows up, and a contract senior engineer is often competent and available by the following week. But a contractor has no standing to say no to the CEO, no stake in the five-year shape of the system, and a contract end date that everyone in the building knows. You’ve turned a leadership gap into a staffing line, and the gap is still there. Just quieter.
What you can do is use contractors to take work off the people who hold those seats, so they stay. The architect who is also covering three vacated services is going to leave too. Give her the services’ backlog to hand to a bridge engineer, and she gets her weeks back for the design work only she can do. That’s the real use of a bridge. It protects the load-bearing people, the handful of engineers who are holding everything else up and who will quietly collapse under three jobs without anyone noticing until the pager goes off at 3 a.m. and nobody answers.
The Clarity Stack for a Merged Org Under Attrition
The most common thing I see in a struggling engineering org is not a technology problem. It’s a clarity problem, and I wrote the three layers up as the Clarity Stack. An acquisition that has lost a third of its key people is that problem in its purest form, because the people who carried the clarity are the ones who left.
So run the stack on the bridge itself. Before the first contractor starts.
Definition of done. Each bridge seat gets an acceptance statement in a sentence or two, written by an employee, that a reviewer outside the seat could check. “Billing reconciliation job runs nightly against both ledgers and the variance report is empty for five consecutive days” works. “Take over billing” doesn’t. Too vague to check.
Written priorities. One ranked list of the dated milestones, visible to both orgs, with each bridge seat attached to the line it serves. If a contractor can’t point to the line, the seat isn’t needed yet. If a line has no seat and no employee, that’s the milestone that slips. Every time.
Decisions in systems, not hallways. Every bridge seat has a named employee who answers its questions and approves its merges. I wrote about the review side in reviewing contractor code without becoming the bottleneck, and the short version is a trust ramp, reviewed merges first and then lighter touch. And the knowledge handoff has a date. If you have leavers still in their notice period, which is the cheapest window you will ever get for knowledge transfer and the one most teams waste on exit interviews, the contractor sits next to them, not after them. That sequencing is the entire argument of bridging attrition with contract engineers around an exit plan. Overlap is cheap. Reconstruction isn’t.
How Long Does the Bridge Last?
Shorter than you fear, and longer than the first plan says. The median KORE1 contract assignment runs 116 days (n=1,887), which is a little under four months. Contract-to-hire conversion across KORE1 contract placements is 37.5% (n=552), and a contractor can convert to your payroll at no fee after 1,040 hours, which is 26 weeks at full time. And the median gap from offer to first day is 3 days (n=1,997). That last number is not the whole search. It’s what happens once someone says yes. Fast, but only after the yes.
So plan the bridge as a first stretch of about four months, with the conversion option sitting at six. Within those four months the permanent org has to answer the real question, which is who you hire to replace what left. If a bridge engineer turns out to be the best person on the team, you have a path. If they don’t, you have an end date. Either outcome beats a slipped cutover.
What does it cost? Here are the three cells I’d price a bridge from, all from the KORE1 Contract Rate Index 2026-Q4, bill rates only.
| Bridge seat | Index cell | Bill per hour (middle half, median) | Three months at the median |
|---|---|---|---|
| Software engineer, all levels | KORE1 observed, primarily Southern California (n=16) | $91 to $120, median $105 | $54,600 |
| Senior software engineer | KORE1 observed, primarily Southern California (n=7) | $91 to $138, median $120 | $62,400 |
| Mid-level software engineer | Modeled, United States national (BLS wages plus 24% burden) | $96 to $122, median $108 | $56,100 |
Read the labels. Please. The first two rows come from KORE1 W2 contract placements started between 2023 and 2026, and they are small samples, so treat the ranges as a guide and not a quote. The third is modeled from BLS Occupational Employment and Wages data for May 2025 with a 24% burden, multiplied by the bill-to-cost range KORE1 observes. Three months is 520 hours. That’s the whole formula. Three senior seats for three months works out to $187,200 at the median.
Whether that is a lot depends on the answer to Devin’s question from earlier. Compared with a slipped cutover and two ledgers through a quarter close, it’s usually not. Compared with a tooling migration that could wait, it is. Do the math on your own list.
How KORE1 Staffs the Bridge
From KORE1. This is the part where we say what we do, and you should weigh it that way.
We place W2 contract engineers, and we’ve been placing engineering talent for more than 20 years. For a bridge, we start from the milestone list rather than a job title. Our recruiters ask what the seat must deliver and which stack it sits in, then submit engineers who have done that exact kind of work, and not a keyword match. KORE1’s average time to fill an IT role is 17 days, the median offer-to-start is 3 days, and our 12-month retention rate on placements is 92%.
When the bridge turns into a permanent seat, conversion is no fee after 1,040 hours. If this fits your situation, see our M&A integration staffing, our contract engineering teams, or post-acquisition systems integration staffing if the exits include systems and finance roles too.
What VPs Ask When the Resignations Start
Can You Really Backfill Acquired Engineers With Contractors Without Losing the System?
For bounded work behind written interfaces, yes. For architecture, customer ownership, and audited controls, no.
The failure I see isn’t contractors being weak. It’s asking them to absorb knowledge that was never written down, after the person who held it has gone. Capture first, then backfill.
Realistically, How Fast Can a Bridge Team Start?
The median gap from offer to first day on KORE1 contract placements is 3 days (n=1,997), and KORE1’s average time to fill an IT role is 17 days.
The slow part is almost never the contractor. It’s the internal week or two it takes to write down what the seat is supposed to deliver, and that is the week to spend before you call anyone.
What If a Contractor Ends Up Being the Best Engineer on the Team?
Convert them. Across KORE1 contract placements, 37.5% convert to the client’s payroll (n=552), and conversion carries no fee after 1,040 hours.
It happens often enough that I’d plan for it. Tell the contractor up front that conversion is a possibility, and tell your own team why a contractor is sitting next to them. Silence breeds the rumor that you’re replacing them.
Does Backfilling Fix a Retention Problem?
No. A bridge buys time, and it does not change why people left.
If the next cliff is four months out, the people still here are doing the same math the leavers did. Use the bridge window to fix leveling, ownership, and the one list of priorities, or you will run this playbook again in the spring.
What Do I Send to Get a Bridge Team Started?
Four things, which are the roles that are leaving, the milestone dates they carry, the start date you need, and how long you expect the gap to last.
A rough version is fine. The milestone dates matter most, because they tell a recruiter what the seat has to deliver and when.
Spend the Bridge on Time, Not on Hope
The month-four exodus isn’t a surprise, and it isn’t a character flaw in the engineers who leave. It’s a calendar. Dates, not moods. You know roughly when the cliffs are, so you can know roughly when the gaps will open, and you can have the milestone list sorted and the bridge seats written down before the Friday payout, not after the Wednesday resignation. Backfill the bounded work. Keep the decisions, the customers, and the audit trail with employees. Then use those 116-ish days, the median length of a KORE1 contract assignment, to build the permanent team properly, because the bridge only ever buys you time and what you do with that time is the whole job.
If you’re holding an integration date right now and the people carrying it are gone or going, connect with me on LinkedIn or DM me there. I’m happy to compare notes. And when you want the seats filled, talk to KORE1’s engineering recruiters.
Related reading: Bridging the Gap With Contractors Instead of Rehiring, Merging Two Engineering Orgs: A 100-Day Integration Playbook, and Inheriting an Engineering Team You Did Not Hire.
