Young ICSID Profiles Part Eleven - My First ICSID Case

Young ICSID is delighted to present the latest edition of its profiles showcasing skilled young professionals in the field of international investment law and dispute resolution. Each issue delves into practical aspects of career development and skill enhancement, offering perspectives from young professionals across the globe. In this installment, we are excited to feature insights from three distinguished attorneys practicing in diverse arbitration roles.

We have invited them to share their experiences from their first ICSID case, along with their unique perspectives and lessons learned from that initial introduction to ICSID: Charlotte Matthews, Associate at HANEFELD, based in Paris; Diana Moya, State Attorney at the Attorney General’s Office of Ecuador, based in Quito; and Juan Felipe Merizalde, Partner at Adell & Merizalde, in Bogota. As with our previous series, these interviews were conducted independently and in writing. There was no coordination or collaboration between the interviewees.

What is your current role and what inspired you to pursue a career in arbitration? 

Charlotte: I am a Senior Associate at HANEFELD in Paris, where I mostly act as counsel or tribunal secretary in international arbitrations. I also occasionally sit as arbitrator.

I have always been passionate about history and international affairs and always dreamt of having a career where I could nurture those interests. Law felt like a natural fit. Like many arbitration practitioners, I happen to be a “third culture kid,” born in Germany to a French mother and an American father. Arbitration specifically appealed to me because it operates at the intersection of diverse legal traditions, languages, and commercial realities—allowing me to work in my different languages, engage internationally, and be involved in matters of significant public and economic importance. It’s truly a dream come true. 

Diana: I am a litigation attorney at the Attorney General’s Office of Ecuador. I was introduced to arbitration shortly after graduating from law school, having had the privilege of joining the Attorney General’s Office at an early stage in my career. Since then, I have worked in the National Directorate of International Affairs and Arbitration (Dirección Nacional de Asuntos Internacionales y Arbitraje), where I developed a deep understanding of international arbitration and have remained committed to this field for nearly 15 years. My professional practice has allowed me to engage with complex cross-border disputes and represent the interests of the Ecuadorian State in international forums.

Juan Felipe: I’m partner at Adell & Merizalde, an arbitration firm I co-founded with my friend, Stephan Adell, after returning to Colombia, following sixteen years practicing at international law firms in Paris and Washington, D.C. My interest in arbitration began when I was 22, during an internship in Paris. I was drawn to how international arbitration blends law, culture, and diplomacy—and how it can serve as a powerful tool for justice in a globalized world.

What was your first ICSID case and how did you become involved in the case?  

Charlotte: I am fortunate enough to say that I did not have “one” first ICSID case, but two simultaneous introductions to the ICSID system. I found myself working on two different cases at the same time in two very different roles: one as counsel for a party in AS PNB Banka and others v. Republic of Latvia, and the other as assistant to the tribunal in Orazul International España Holdings S.L. v. Argentine Republic. I was staffed as counsel on the AS PNB Banka case by one partner at my firm, and became assistant in Orazul on the proposal of another partner at my firm, who was the president of that tribunal. This dual experience was the best introduction to ICSID practice that I could have ever wished for: to be immersed in representing a client’s interests in one case and getting insight into the considerations that help shape tribunal decisions in the other.

Diana: My first ICSID case was a highly prominent one, known as Occidental Petroleum Corporation and Occidental Exploration and Production Company v. Republic of Ecuador (ICSID Case No. ARB/06/11). I was assigned as lead attorney during the annulment phase of the award. At the time, I had been working at the Attorney General’s Office for three years—having recently secured a fully favorable award for Ecuador in a different case—which led my supervisors to entrust me with the responsibility of handling the annulment proceedings, even though I was only 26 years old. 

Juan Felipe: My first ICSID case was Occidental v. Ecuador II (“Oxy”). It was also the first investment arbitration our team handled. I worked on the case from 2007 to 2014, experiencing it from start to finish.  I lived through it all, starting as an intern and eventually becoming a mid-level associate. In many ways, I grew up professionally with that case. It shaped not only my understanding of investment arbitration but also my approach to advocacy, strategy, and teamwork.

What were the biggest challenges you faced during that case and how did you overcome them?

Charlotte: Dealing with the critical mass of information of the case and the sheer volume of the documentary record was one of the greatest challenges of those early cases, which involved extensive records of thousands of pages across submissions, witness statements, expert reports, and exhibits. I found it particularly difficult to navigate between two lenses: maintaining meticulous attention to specific documentary details while simultaneously preserving a coherent understanding of the case theories. Switching between granular analysis and holistic case theory was a very demanding cognitive exercise.

What proved invaluable was relying on guidance from more experienced colleagues who developed systems for information and time management in large-scale arbitrations. Their mentorship helped me establish a sound approach to document organization and case mapping that I continue to use today. Collaborative problem-solving also happens to be one of the things I most enjoy with my work.

Diana: The arbitration received significant media attention in Ecuador due to the amount awarded, which at the time was one of the largest sums ever granted by an ICSID Arbitral Tribunal—over USD 1.7 billion. Once the award was issued, it triggered a major effort on the part of the State’s legal defense team. We had to explain to various sectors of Ecuadorian society the nature of international arbitration, the implications of having an ICSID award issued against the State, and the next steps to be taken within a complex annulment proceeding—one that was highly demanding in terms of legal requirements and uncertain in its prospects of success.

On a personal level, it was an extraordinary challenge. I was a very young attorney working on a case of great national importance—one that was widely known in the investment arbitration community at the time. I had to push myself to perform at my highest potential and to demonstrate that I was capable of contributing meaningfully to such a high-profile case. Fortunately, I was surrounded by an exceptional team of highly skilled professionals, with whom it was both an honor and a pleasure to work. 

Juan Felipe: Oxy was a complex case. It lasted 9 years. It was trifurcated and each side had two large law firms. Between the main arbitration and the annulment, the case had nine substantive hearings. Over the course of nearly a decade, many people came and went, which made continuity and institutional memory a real challenge.

The sheer size of the case file was overwhelming at times—especially given the technological limitations we faced back then. I’ll never forget the day we had to file one of Ecuador’s main submissions: it involved nearly 100 binders, each of which had to be printed, reviewed, indexed, and page-turned by hand. On the day of the courier pickup, the entire team—from interns to senior partners—sat on the floor, going binder by binder to make sure everything was perfect.

Through that experience, and under the leadership of great attorneys, mentors and friends, I learned how critical teamwork and organization are when managing large, complex cases. Over time, and with experience and technology, handling massive files became easier. But that moment really stayed with me—it showed me what dedication, collaboration, and precision look like in practice.

Name one lesson you learned from that early case that stayed with you throughout your career. 

Charlotte: I have been particularly fortunate to live both the counsel and tribunal secretary perspective concurrently and one lesson stuck with me: it is always worth leaving no stone of a case unturned. Working as tribunal secretary, I witnessed how arbitrators respond to comprehensive, well-researched arguments and have appreciated how counsel anticipate questions before they even arise. Conversely, as counsel, I have seen how seemingly minor details can unexpectedly become pivotal to the outcome. I have found that investment arbitration cases are rarely won on grand theories alone, but often turn on meticulous preparation and factual detail.

Diana: When the Office of the Attorney General of Ecuador filed for the annulment of the Occidental award, we knew it would not be an easy path. We had strong confidence in our legal arguments, although we were fully aware that the chances of success were very limited. We fought until the end and gave our absolute best—and ultimately achieved a partial annulment of the award.

That case taught me—and more importantly, helped me internalize—a lasting lesson: no matter how difficult the case, how high the amount in dispute, or how powerful the parties involved, no battle is fought in vain when the law and reason are on your side. 

Juan Felipe: That case also taught me the value of teamwork, a lesson that has stayed with me throughout my career. Collaboration mattered not just within our firm, but also with co-counsel. Everyone had a role to play, and even the smallest task made a difference. I’ve carried that mindset with me ever since. To this day, on the night of a major filing, I’m right there with my team, hands-on, going over every detail (although I don’t miss the paper filings…). 

I still remember the liability hearing in Paris. I was just an intern—serving coffee, making copies—but I stayed fully engaged. At the end, lead counsel thanked me by name. That moment showed me that in a case of that scale, every contribution counts. No matter your title, you are part of the outcome.

What advice would you give to young practitioners who are about to handle their first ICSID case? 

Charlotte: So much of what I have learned in my early career cannot be found in textbooks. For young practitioners approaching their first ICSID case, I would have two tips: First, master the specific facts of the case as disputes often turn on facts, rather than on law. Second, actively seek mentorship from experienced ICSID practitioners who can guide you through the unwritten strategic considerations of an ICSID dispute. 

Diana: The world of international arbitration can be intimidating. It involves some of the most skilled and prestigious lawyers globally, legal discussions that can be extraordinarily complex, and amounts in dispute often reaching into the billions of dollars—making the potential financial impact on state budgets extremely significant.

Nonetheless, it is important to remember that youth is not a disadvantage; on the contrary, it enables us to bring fresh and innovative perspectives to the cases we handle. What truly matters is being thoroughly prepared and standing firm in what we believe. We must always give our best and be willing to seek out arguments, documents, or witnesses to the ends of the earth, if necessary—when defending the state, this is no exaggeration. In the end, the satisfaction of defending your country and the interests of its people is simply indescribable. 

Juan Felipe: "Mind the details." Know the case file as if it were your own résumé. Nothing undermines a case, or your credibility, more than a question that goes unanswered because no one had a full grasp of the record. In investment arbitration, details are not just technicalities, they shape the narrative, the strategy, and ultimately, the outcome. So, take ownership, stay curious, and never assume that something is too small to matter.

What is your motto in life?

Charlotte: I am inspired by a framed quote that sits on the desk of my mentor, Inka Hanefeld. It reads “It gets better and better.” I am convinced that virtue nurtures virtue. This positive outlook guides me both through personal life and arbitration.

Diana: “No battle is small, nor effort wasted, when the goal is just and true.” 

Juan Felipe: "Fall seven times, stand up eight." I truly believe that failure is essential for success. Personal and professional setbacks have taught me resilience, humility, and perspective, and ultimately brought me to a place I deeply value. I find strength in the idea that perseverance and optimism can carry us through even the toughest moments. 

The opinions expressed in this publication are those of the interviewees. They do not purport to reflect the opinions or views of ICSID, nor those of the organizations with which the interviewees are associated or employed.