Exosens – Quynh-Boi Demey (IPO Stories, Ep. 38)

Transcript

[0:06] Per Einar Ellefsen: In today’s episode I sit down with Quynh-Boi Demey, the CFO of Exosens, a French industrial tech company that listed in Paris in June 2024. 

[0:50] Per Einar Ellefsen: Exosens specializes in advanced imaging and sensing solutions for demanding environments such as aerospace, defense, and scientific research. It is best known as a leading non-US manufacturer of light-enhancing tubes for night vision, but also develops a broad range of complementary technologies including high-performance photodetectors, infrared sensors, and scientific imaging systems used in industrial inspection, medical diagnostics, and space exploration. Exosens was listed in 2024 in a €400 million transaction at a market cap of €1 billion. Today it’s valued at more than €2 billion, and the private-equity sponsor HLD has sold additional shares in three successful follow-on offerings in 2025. With Quynh-Boi we go through the timing and preparation of the IPO, the transition from being owned by a private-equity firm to being listed, the importance of meeting or beating the IPO guidance, and the benefits of being publicly listed. 

[1:39] Per Einar Ellefsen: Welcome, Quynh-Boi. I’m here today in the offices of Exosens. 

[2:09] Per Einar Ellefsen: Exosens is a company that did its IPO approximately one year ago, and it’s been very successful. We’ll go into the details with Quynh-Boi, the CFO. Quynh-Boi, can we start with you presenting yourself? 

[2:21] Quynh-Boi Demey: Yes, thanks Per. I was born in Vietnam and raised and educated in France. I started my career almost 30 years ago, first in external audit with EY and PwC, both in France and also in Ivory Coast and Thailand. Then I held various finance positions in large industrial tech companies such as GE and TotalEnergies. I joined Exosens three years ago as CFO, and I live in Paris with my husband and my two sons. 

[2:49] Per Einar Ellefsen: Can we start with a bit of background on Exosens? When I first met you the company was actually called Photonis. Can you tell us where the company is coming from and what business you’re in today? 

[3:01] Quynh-Boi Demey: We are newly listed, but the history of Exosens started in 1937 in Brive-la-Gaillarde, in southwest France, as a subsidiary of Philips. Over the decades, this small company became a pioneer in critical technologies such as micro-channel plates and electron multipliers. We still use this technology for night-vision goggles—basically to see in low-light conditions. We also manufacture particle detectors, and our products are used even in space missions. 

[3:34] Quynh-Boi Demey: Fast-forward to 1998: the company went through its first big transformation, spinning out of Philips and rebranding as Photonis. From there we quickly positioned ourselves as a global leader in low-light imaging and particle detection. In the 2000s Photonis went international, acquiring Burle, a former GE company, and Delft, our main competitor in the Netherlands. That move strengthened our position across defense, nuclear instrumentation, and life sciences. The turning point came in 2020. 

[4:14] Quynh-Boi Demey: A proposed acquisition by the US company Teledyne was blocked by the French government for strategic reasons. With only two global players in light-intensifier tube technology and both based in the US, allowing the deal would have made France and the EU heavily dependent on American technology in a critical sector—allowing soldiers to see in the dark. 

[4:43] Per Einar Ellefsen: So you’re basically the only provider outside the US for the technology for night-vision goggles, right? 

[4:49] Quynh-Boi Demey: Yes, exactly. In response, the group HLD stepped in the following year. The acquisition safeguarded European technological sovereignty and provided us with capital to support our growth strategy. What followed were years of transformation. A new leadership team was appointed and we created several key positions: Chief Strategy Officer, Chief Technology Officer, and Chief Operating Officer. Between 2021 and 2023 we operated under our new name, Exosens, and we acquired several companies expanding our technology—Xenics, Telops, ProxiVision, and Elmo. 

[5:33] Quynh-Boi Demey: These strategic moves extended our capabilities across the full light spectrum, from ultraviolet to thermal infrared. In 2024 we listed on Euronext Paris. The offering raised €402 million, including €180 million of primary proceeds used to refinance our debt and support the next phase of growth. Since going public, we’ve maintained strong momentum, combining organic expansion with strategic acquisitions. We acquired Centronic in the UK, Elatec in Canada, Noxant in France, and we closed NV Lambert Instruments on Tuesday this week. 

[6:16] Quynh-Boi Demey: We’re now a global champion in four verticals—defense, industrial controls, nuclear instrumentation, and life sciences—with very diversified applications and a clear path forward in sectors critical to innovation and security. 

[6:30] Per Einar Ellefsen: With the experience of being owned by a private-equity firm, why did you decide to go public? 

[6:35] Quynh-Boi Demey: Technology is truly at the core of our DNA, but developing our kind of technology isn’t a short-term endeavor. From the first idea and technological brick to a product can take up to seven years. During this phase we go through prototype, development, qualification, and finally full-scale production. It’s long and demanding, and that timeline doesn’t always align with a typical LBO. 

[7:10] Quynh-Boi Demey: Looking ahead, we saw public markets as a perfect fit because they offer a longer investment horizon that naturally aligns with our development cycles. On top of that, we had reached operational maturity to meet the regulatory and governance standards of a listed company. Going public also helps us strengthen internal processes, raises visibility globally, and helps attract talent. And being listed in Paris provides a long-term solution to our sovereignty issue—headquarters and capital anchored in Europe puts that behind us. 

[8:03] Per Einar Ellefsen: Did the government put any limits on the need to maintain French or European shareholders even post-listing? 

[8:12] Quynh-Boi Demey: Yes, 10%. 

[8:13] Per Einar Ellefsen: You still have to keep 10% post-listing. There are similar restrictions in airlines, for example. In terms of timing, you listed in June 2024. How did you decide on that timing—was it right, too early, too late? 

[8:29] Quynh-Boi Demey: You don’t actually get to choose the exact timing of an IPO. You decide to be ready, but the market ultimately decides when the window opens. Once it does, you have to move fast; if it doesn’t, you need to be ready to pause. We decided around mid-2023 to prepare. Markets were largely closed and uncertainty was high, but we stayed the course—prepared the prospectus for the regulator—and remained pragmatic: if the window didn’t open, we would wait. 

[9:21] Per Einar Ellefsen: So you started work on the IPO in mid-’23? 

[9:25] Quynh-Boi Demey: Yes. 

[9:25] Per Einar Ellefsen: When did you feel you were ready to seize the window? 

[9:30] Quynh-Boi Demey: You never know. You can’t be fully ready, but you must be ready enough to start—then you learn by doing. 

[9:44] Per Einar Ellefsen: Did you look at any other alternatives? 

[9:47] Quynh-Boi Demey: Not really. We didn’t run a dual-track; we went all-in on the IPO route. If things hadn’t worked out, our shareholder might have looked at other options, but our mindset was: prepare thoroughly and give the IPO our best shot. 

[10:09] Per Einar Ellefsen: Listing venue—French roots, quite international now. Was there any debate about where to list? 

[10:16] Quynh-Boi Demey: Not really. Given past sovereignty issues, Paris made the most sense. We briefly considered other European markets such as Amsterdam—we have a significant subsidiary there—but with HQ, CEO, CFO, and many ExCom members in France, Paris was the natural choice. 

[10:46] Per Einar Ellefsen: There aren’t many pure peers listed, but around the same time one of your clients, Theon, listed in Amsterdam, and there are other defense names like Hensoldt that listed in 2020. How did investors think about you versus others—were those used as points of comparison? 

[11:06] Quynh-Boi Demey: Yes, even though there isn’t a perfect public peer. About 70% of our business is in defense, but most defense peers you named are at a different point in the value chain—large OEMs that assemble our components. On the industrial side we have public peers such as Hamamatsu, but they don’t operate in defense. The one that resembles us the most is Teledyne, which wanted to buy us—but they’re much bigger. 

[11:48] Per Einar Ellefsen: It’s difficult to compare different scales. We talked about mid-’23 and an IPO mid-’24—was mid-’23 the start of all IPO prep? How long did that phase take? 

[12:03] Quynh-Boi Demey: The decision was mid-2023, but we started behind the scenes early 2023. The whole process took about eight months. After deciding in summer ’23, we launched an RFP to select the banks. We kicked off with the selected banks in November ’23, launched the workstreams, and listed in June 2024. 

[12:32] Per Einar Ellefsen: As CFO, did you need to dedicate a lot of new resources? What was most challenging? 

[12:53] Quynh-Boi Demey: We have a relatively lean finance team and didn’t hire specifically for the IPO, but we were supported by advisors—an independent financial advisor, legal and accounting experts, communications consultants, and of course the syndicate banks. Internally, we built dedicated teams around the project using existing resources. 

[13:23] Quynh-Boi Demey: By the time we decided to go public, we’d already reached a solid level of operational maturity. Our leadership team was in place, which gave the CEO and me space to focus on critical phases like early-look and analyst presentations, while the rest of the team focused on day-to-day operations. I already had a very strong FP&A team. I did strengthen in a few areas through 2023—M&A, treasury/financing, internal audit, consolidation, and corporate legal—but that was to structure for long-term growth, not just the IPO. 

[14:29] Per Einar Ellefsen: At the same time as the IPO, you were integrating acquisitions, which is already quite challenging. 

[14:36] Quynh-Boi Demey: True—but we hired to support those processes. Day-to-day operations were handled by the teams; the IPO workload was largely with our CEO Jérôme Cerisier, our COO, and myself. 

[14:52] Per Einar Ellefsen: What do you think was the most challenging part? 

[14:55] Quynh-Boi Demey: Two moments are really critical. First is setting the guidance. You must be ambitious and realistic—finding the balance is always the hardest part. We had lots of debates between the CEO and me, and with the financial advisor, the banks, and our shareholders. 

[15:25] Per Einar Ellefsen: Internal communication—1,700 employees—how did you manage that? 

[15:41] Quynh-Boi Demey: It’s tricky. During the private phase you want confidentiality and to avoid leaks, so strong project management and controlled communication flows were essential. Once we decided to go public, we wanted to bring the whole company along—this had to be a company project, not just a leadership initiative. We communicated thoroughly about why we were going public and what it would bring. 

[16:11] Per Einar Ellefsen: What were the advantages for employees of being public? 

[16:24] Quynh-Boi Demey: Attracting top-tier talent—brand awareness, visibility. Also long-term visibility for the company’s development. In LBOs, every three to four years a sale process can be a disruption; you never know your next shareholder or their strategy. Being public gives long-term support for growth. 

[16:58] Per Einar Ellefsen: Your private-equity shareholder HLD accompanied you through the process. How did they support you? 

[17:06] Quynh-Boi Demey: HLD has always been both demanding and supportive—not just during the IPO but more broadly. They brought perspectives, challenged our thinking constructively. During the IPO we had open, honest discussions on key decisions—bank selection, deal structure. While views differed, we aligned in the end. Their involvement was a real asset. 

[17:43] Per Einar Ellefsen: That relationship evolved since you listed—they’re no longer majority, have sold three blocks; you’ve added new board members and investors like Bpifrance. How has the shareholder relationship evolved? 

[18:03] Quynh-Boi Demey: There was a turning point before vs. after the IPO. Before, they had access to many documents and could ask lots of questions. After, everything goes through the board, and all board members must have the same level of information. No quick calls—board process. They had to adapt, and our legal advisors helped. They used to bring M&A expertise; we also built our own M&A and strategy teams—doubling those teams. 

[18:50] Per Einar Ellefsen: On regulation, the prospectus is a huge document. What’s your impression working on it? 

[19:10] Quynh-Boi Demey: The good thing is it forces you to present business model, products, and risks thoroughly and clearly. The downside is repetition across sections—dense and hard to read. A year after the IPO we redesigned to remove repetitions; the updated version we released end of April is much clearer. The prospectus feels like a check-the-box regulatory document. 

[19:50] Per Einar Ellefsen: That’s the challenge: it’s designed so everyone, including retail, has access to all info—though few retail investors read it. In France the prospectus is often published earlier than elsewhere; when it arrives only at book-build it’s late. Sometimes new disclosures—like management remuneration—appear there. Speaking of retail, you used an innovative process—only the second company in France to do an accelerated offering without retail. Had you launched this year, you might have included retail. Why not include retail then? 

[20:59] Quynh-Boi Demey: We wanted to shorten exposure to market fluctuations—from eight trading days to just three. That made a real difference. We listed on June 7; two days later, on June 9, President Macron called snap elections after the EU results—creating months of uncertainty in France. Had we not chosen this route, I don’t know if we’d be listed today. It’s a reminder that hard work isn’t enough—you need preparation, some luck, and active risk management. Accelerating the process was the right choice. 

[21:53] Per Einar Ellefsen: You chose the syndicate banks via an RFP in November for a mid-year IPO. What were your criteria? 

[22:06] Quynh-Boi Demey: We launched the RFP at the end of summer; pitches were in September 2023. Our independent financial advisor helped shape it. Criteria: ECM track record; experience of the deal team; grasp of our equity story; credibility of proposed valuation; distribution strength and research; fees; and ability to refinance our debt. We also considered personal and cultural fit—someone said you’ll spend more time with your banks during the IPO than with your spouse! 

[23:05] Per Einar Ellefsen: On valuation: banks pitch a number, but the market decides. How do you sort realistic from not? 

[23:16] Quynh-Boi Demey: First, benchmark valuations across banks—see who’s an outlier. Second, examine their reasoning—peer sets and methodology. And our shareholders come from investment banking and know valuation well. All of that gave good benchmarks. 

[23:50] Per Einar Ellefsen: A common investor pushback: if PE is selling, why should I buy? They know more and timed it. Did you get that, and how did you answer? 

[24:08] Quynh-Boi Demey: It wasn’t widespread, though I did get a provocative question from a UK investor asking if I was hired by PE for the IPO and whether our business plan was really ours or PE’s. So yes, perhaps our guidance and story were examined more closely because PE was selling—an extra layer of scrutiny. 

[24:47] Per Einar Ellefsen: You mentioned IPO guidance as one of the trickiest parts. You’ve beaten it since listing—congrats. How did you set it and what advice did you receive? 

[25:04] Quynh-Boi Demey: Our CEO Jérôme and I both took the Euronext IPOready program. Every speaker emphasized: meeting first-year guidance is absolutely critical. Miss it, and you lose investors’ trust for years. With that in mind, we aimed for ambitious yet realistic guidance. Finding the balance required intense discussions with our board and advisors. We knew we had to get it right. 

[26:06] Per Einar Ellefsen: Is it harder to guide public investors than a PE owner you can update more frequently? 

[26:18] Quynh-Boi Demey: Different difficulties. Private owners are demanding and have detailed info; they can challenge everything. But if you miss guidance, it often won’t change their financial support. With public investors, saying what you’ll do—and then doing it—is critical to build trust. They also constantly compare you to peers and market conditions outside your control. 

[27:15] Per Einar Ellefsen: Exactly—it’s about trust. Many investors won’t invest until they’ve seen a management team deliver for a few quarters. Then they’ll underwrite numbers with more confidence. 

[28:05] Per Einar Ellefsen: Let’s talk investor interactions. You met a lot—including us. How global were the interactions? 

[28:27] Quynh-Boi Demey: At IPO, our free float was ~35% of share capital. About one-third of that came from French investors; over 50% from the US and UK; <10% from the rest of the world. One year later, free float is ~60%, with the majority of investors now outside France. Our global business is reflected in our increasingly international base. 

[28:57] Per Einar Ellefsen: When did you start meeting investors? 

[29:01] Quynh-Boi Demey: Our first meetings were in March 2024, about three months before the public launch. Starting earlier wouldn’t necessarily have changed much; it’s about building momentum, and we wanted to be fully prepared to explain our strategy and value-creation model. Those three months were intense—103 meetings; some investors met us three times before the deal closed. 

[29:34] Per Einar Ellefsen: I think we were part of that, yes. How many different investors in all? 

[29:41] Quynh-Boi Demey: We counted meetings, not unique investors. It was focused and demanding—but it worked. 

[29:50] Per Einar Ellefsen: How many did you meet before launch? Many new ones during the roadshow? 

[30:00] Quynh-Boi Demey: Many new during the public launch—some informed only a few days before and told us they’d have liked earlier notice. 

[30:13] Per Einar Ellefsen: Did different investor categories focus on different parts of the story? 

[30:20] Quynh-Boi Demey: Definitely. US investors are familiar with industrial-tech models growing both organically and through bolt-on M&A—so their interest covered all four verticals. European investors tended to focus more on defense, which remains our core market and the majority of sales. 

[30:45] Per Einar Ellefsen: That could mean US investors gave higher price feedback if they valued M&A opportunities. A challenge with bolt-on models is some investors won’t value future M&A at IPO. On defense, was there pushback? 

[31:29] Quynh-Boi Demey: At the start we worried some investors would be restricted from defense. A few declined meetings due to restrictions. Others did thorough due diligence on how our products are used, often consulting ESG teams early. After review, most roadblocks were lifted. A year later, we’ve even met investors—especially in the Nordics—who initially couldn’t participate but are now interested. 

[32:10] Per Einar Ellefsen: Liquidity is always a challenge for recent small/mid-cap listings. You had a very strong IPO book—about five times covered—but performance was flat for the first six months; the share price really took off this year. How did you think about liquidity? 

[32:37] Quynh-Boi Demey: Liquidity was the second key takeaway from IPOready, after meeting guidance. It’s a chicken-and-egg: some investors hesitate to buy if they fear they can’t sell; without buyers, liquidity won’t improve—leading to a discount. That shaped our thinking in two ways. First, we needed sufficient size at IPO to support liquidity. Even at ~€1bn valuation and ~€350m free float, we saw limited liquidity at first. Second, post-IPO liquidity events matter. Our liquidity contract helped a bit, but the biggest improvement came when our shareholder gradually injected liquidity via three blocks after the lock-up. With ~60% free float now, liquidity is significantly improved. 

[33:58] Per Einar Ellefsen: Now that you’ve been public a year, has it helped the company? Changed day-to-day? Help M&A? 

[34:11] Quynh-Boi Demey: Being public offers a longer investment horizon—fitting our long development cycles—and easier access to capital for organic growth and M&A. We haven’t tapped equity for acquisitions yet, but if a larger opportunity arises, being public gives us an edge. It’s also pushed us to strengthen internal processes, especially financial reporting, and boosted global visibility with customers, suppliers, and talent. 

[34:53] Per Einar Ellefsen: Does that mean you’re more likely to use shares for deals, or simply that equity is easier to raise? 

[35:04] Quynh-Boi Demey: Mainly that it’s easier to raise equity. 

[35:07] Per Einar Ellefsen: What’s your main advice for a management team preparing for an IPO? Anything you wish you’d heard beforehand—even after IPOready and our podcast? 

[35:24] Quynh-Boi Demey: Three key lessons. First: time is of the essence. You can’t control the window, but you must be as ready and fast as possible when it opens. Our banks said preparing an analyst presentation in one month was unrealistic—recommendation was 1.5–2 months and to push our listing. We didn’t follow that; we were ready in a month. Accelerating, including going without a retail tranche, let us list just two days before the snap parliamentary elections—timing that might have delayed or complicated the IPO. Move fast. 

[36:15] Per Einar Ellefsen: It sounds like you were driving that more than your advisors. 

[36:21] Quynh-Boi Demey: Yes. We wanted to be ready fast—not to miss the window, but willing to pause if needed. Second: use the IPO long-term goal to improve operational performance, not just to get listed. We always kept in mind the IPO might not happen, so we avoided costs that would stick if we stayed private—hence no IPO-specific hires. For example, we built a fast financial close not just because it’s required for public companies, but because it improves operations. Having numbers earlier lets you implement actions earlier and react quickly. Everything we implemented had to be useful operationally, IPO or not. 

[37:28] Per Einar Ellefsen: Closing quickly frees the rest of the quarter to plan, not just close books—so the organization moves faster. 

[37:41] Quynh-Boi Demey: Exactly. You don’t lose a month of action. Third: move fast, but take your time on critical decisions. Two moments stand out—building the business plan and setting guidance (ambitious yet realistic), and defining deal structure and size (large enough for liquidity, small enough to close). These require deep discussions among CEO, CFO, shareholders, board, and banks. Even though the process is fast and technical, management must keep control at these key moments. 

[38:43] Per Einar Ellefsen: With a year’s hindsight, what changed in your role as CFO of a listed company? 

[38:49] Quynh-Boi Demey: Time management is more challenging. In addition to usual responsibilities, I now have investor meetings and governance—sustainability, audit committee, board meetings. Bringing on an Investor Relations Director and a corporate lawyer has helped a lot. 

[39:12] Per Einar Ellefsen: Did you bring IR in after the IPO or before? 

[39:15] Quynh-Boi Demey: After—and that’s one regret. 

[39:18] Per Einar Ellefsen: You were concerned about committing to a cost. 

[39:20] Quynh-Boi Demey: Yes. If we didn’t go public. Ideally, IR should start at the beginning of the public phase—about one month before listing—because the risk of not completing is much lower and IR can start building relationships. If I had to do it again, I’d hire earlier. 

[39:42] Per Einar Ellefsen: That’s common feedback—we hear it a lot. IPO marketing is just the start of a relationship. Did many investors you met at IPO invest six to twelve months later? 

[40:05] Per Einar Ellefsen: 

[40:17] Quynh-Boi Demey: Yes—some didn’t come in at IPO but invested later. 

[40:23] Per Einar Ellefsen: Any other differences you noticed across investors—feedback quality, demand? 

[40:40] Quynh-Boi Demey: Some provided very detailed feedback; others less so. It often depends on the individual. Some did thorough due diligence and knew a lot about us; others came in cold. Different levels of knowledge. 

[41:07] Per Einar Ellefsen: On guidance—you debated with shareholders, board, advisors. Was there any feedback loop with investors to adjust it? 

[41:32] Quynh-Boi Demey: No. We decided after significant internal debate. Once we reached a balanced view, we wouldn’t have changed it. 

[41:40] Per Einar Ellefsen: Last question—any fun facts or war stories from the IPO process? 

[41:47] Quynh-Boi Demey: Absolutely. Since we operate in B2B with a wide range of applications, we traveled with a heavy suitcase full of demos. 

[41:58] Per Einar Ellefsen: I remember the suitcase very well. 

[41:59] Quynh-Boi Demey: Everything from light-intensifier tubes and ion detectors to core infrared cameras and micro-channel plates. Most of our products are dual-use, so we needed export-control clearance just to travel from France to the UK. We were concerned at customs with this big suitcase, but everything went smoothly. In Paris, Jérôme and I zipped between meetings on bicycles—it was always a headache deciding who carried the suitcase and how to move it from place to place. 

[42:35] Per Einar Ellefsen: It doesn’t exactly fit on a Lime or Dott bike, right? 

[42:38] Quynh-Boi Demey: No—but it was worth it. The demos made things much more concrete for investors. 

[42:44] Per Einar Ellefsen: I’m still waiting for the invitation for the site visit in Brive-la-Gaillarde that we talked about, but you moved very fast—you didn’t have time. Thank you very much for joining us today, Quynh-Boi. It was great to have you, thanks for sharing your experience, and best of luck with the next years as a listed company. 

[43:01] Quynh-Boi Demey: Thank you. 

[43:03] Per Einar Ellefsen: Thank you for listening to IPO Stories. In future episodes, we’ll host CEOs, CFOs, advisors, investors, and other participants in the IPO process to learn from their experience—like from Quynh-Boi today. If you like the show, please follow us on Spotify or Apple Podcasts and share the show with people around you. If you have questions about the IPO process that you’d like us to address with future guests, please get in touch at contact@ipostories.com and follow our LinkedIn account. Amundsen Investment Management.