Meet Bloomberg’s C++ Guild

C++ is at the heart of Bloomberg’s infrastructure, powering everything from low-level libraries to highly performant financial applications, analytics, and trading systems. Maintaining a best-in-class C++ environment requires a collaborative approach to knowledge sharing and continuous education, and that’s where Bloomberg’s C++ Guild comes in.

The C++ Guild is one of 12 guilds Bloomberg has created to provide structured forums for people to share technical knowledge, tools, code, and best practices. The C++ Guild, in particular, is dedicated to strengthening Bloomberg’s use of the language and related areas such as training, ISO standardization, and application design. Guild members’ influence also extends across the industry through tech talks at key conferences and meetups, open source contributions, and through the standardization process. Through these efforts, the Guild ensures that Bloomberg remains a C++ innovator, while empowering the broader tech community to drive the language forward.

However, the Guild isn’t just a technical forum. It’s also a catalyst for professional growth. Members gain opportunities to sharpen their expertise, learn from industry leaders, and become recognized technical experts themselves. We asked individuals from this community to share more about the C++ Guild and discuss how it has shaped each of their careers.

First, let’s meet Aurelien Cassagnes, a Tokyo-based Team Lead in Bloomberg’s Feeds Engineering group. He started in 2015 as an intern and then served as an individual contributor (IC) for eight years before becoming a team lead in 2024.

How did you get involved with the C++ Guild? And what is your role in the Guild?
I knew someone else from the APAC region was involved in the C++ Guild’s API Reviews Working Group, so I decided to join that same group to keep our efforts focused.

The API Reviews Working Group is tasked with defining best practices for the most fundamental APIs used at Bloomberg and ensuring compliance. It also brings together engineers with different skills and backgrounds to review far-reaching internal libraries or code that is used in open source projects that Bloomberg publishes. For example, before the release of BlazingMQ, a modern high-performance open source message queuing system, the C++ Guild’s API Reviews group was extensively involved in reviewing its code.

How did you become a co-lead of a Working Group?
My group lead and I discussed my available bandwidth to focus on this guild, while still being able to deliver for my team. I later decided to also join the Conferences Working Group in order to bring back some of the expertise in the region, as it’s quite challenging to source events locally.

The two prior co-leads of the API Reviews Working Group were happy with the work I was doing there and they trusted me to lead the local chapter. I started some other local initiatives to grow the guild, such as making sure that our teams know what services we provide and finding opportunities for our engineers to participate in Standards Committee meetings or write C++ standards proposals. Those efforts were ultimately rewarded with being picked as a Guild Leader, which is a title I wear as proudly as Team Lead.

We recently launched another working group locally to handle the writing of a standards proposal. All in all, having participated in multiple groups has shown me the power of building a strong network in the guild.

What do you tell engineers about why they should get involved in the C++ Guild?
Guilds are the perfect place to stretch your engineering muscle beyond your day-to-day tasks. You’ll work alongside world-class experts who are excited to share their skills. So if you are looking for a venue to grow as an engineer, this is a great place. The guild is not only for you to receive; we are also interested and open to see what you want to contribute. The guild is an investment, and you get tenfold the time and effort you put in.

How has the C++ Guild community supported your career development?
As the guild looked to expand its presence in APAC, they trusted me to lead the local chapter, and thus was positively noticed and supported by my manager. Because I was invested in finding opportunities for our engineers, I took even more initiative and nominated and sent my people to events, and this was also noticed. I have no doubt that these were some of the milestones that were considered when my managers decided to make me a team lead. It’s safe to say that I feel a whole lot more complete as an engineer thanks to being in the guild.

Last year, you attended CppCon. Why is it important for Bloomberg engineers to attend, participate, and speak at technical conferences?
While we are immersed in our day-to-day work, it’s easy to forget that best practices and the bar for excellence in C++ is a moving target. But the language keeps evolving. Bloomberg aims to lead this movement, and is committed to being a strong voice in the C++ Standards conversation. So we want our engineers to be engaged in the community, to learn from it, and to give back.

This starts by fostering a culture of curiosity and openness. Question the status quo, understand where we are, and improve on it. We invest in our engineers so they have the opportunity to share what they know with the community at a conference or a local meetup, get feedback, and take their ideas to the next level. Ultimately, when an engineer presents a proposal on stage at CppCon, they will reach and influence the community at scale, so we make sure we utilize that opportunity for both our business’ and the individual’s growth.

“Guilds are the perfect place to stretch your engineering muscle beyond your day-to-day tasks. You’ll work alongside world-class experts who are excited to share their skills. So if you are looking for a venue to grow as an engineer, this is a great place.”

– Aurelien Cassagnes

Elena Vorobyeva is Team Lead on the Sessions Infrastructure team, part of Platform Security. She first joined Bloomberg as a contractor on the Real-time Data team. She eventually accepted a permanent position working on application middleware, and then market data.

Tell us about how you got involved with the C++ Guild?
I am the Lead of the C++ Guild’s Conference Working Group. When I first joined the guild in 2019, there were several groups within the Guild that were in need of leadership. I chose to lead the Conference Working Group because national and international conferences create possibilities for community-wide professional development and education. I also enjoy sharing my own fascination with and knowledge of C++.

What is your Working Group charged with?
The Conference Working Group is responsible for managing conference-related activities. Each year, we recommend which conferences related to C++ that the Engineering department should sponsor. We decide which sponsorship level best aligns with Bloomberg’s objectives. We also provide support and assistance to individuals participating in these conferences, whether as first-time attendees or seasoned presenters. This ensures that our team members are well-prepared and can make the most of their conference experience.

Why is it important for Bloomberg engineers to attend, participate in, and speak at technical conferences?
Each year, Bloomberg participates in more than a dozen C++ conferences around the globe. We also have many engineers involved in WG21, the ISO C++ Committee that helps shape the international standard for the C++ language. Bloomberg has one of the world’s largest C++ codebases, and as that investment grows, it is important to show our commitment to this language, which leads in both performance and safety.

Bloomberg’s engineers are widely recognized as thought leaders and experts in the field. At conferences and on committees, we also have a chance to discover insights, share perspectives and get inspiration from experts outside the company.

Conferences are also an excellent way to show potential talent that Bloomberg is not only a financial services company, but also a leading software company. In addition to presenting our work, we get to share our unique company culture, where people can stretch professionally and contribute to the evolution of technology. People from other companies tell us that they are fascinated that every Bloomberg employee they talk to tells the same story: we love where we are, and we trust that we are appreciated.

Our own employees come home from these conferences with a renewed appreciation for what Bloomberg offers, both professionally and as a place to work and grow. The chance to present their work to outside audiences offers people a moment to step back and understand what they have accomplished and how much that matters to the greater C++ community.

How has the C++ Guild community supported your career development?
The Guild community continues to introduce me to a network of talented and driven people outside of my own department. The meetups and events organized and supported by the Guild have given me the opportunity to deepen my technical knowledge in C++ and other related areas. Being involved in the Conference Working Group has allowed me to mentor colleagues across the company. I feel like I am helping to create – while also being given – a comprehensive platform for both personal and professional growth.

What makes guilds a great way for engineers to learn new skills and develop their interests in emerging technologies?
Guilds provide a dynamic environment to share information both throughout our company and externally as well. Interaction with a diverse array of Working Groups allows contributors to focus on many aspects of professional development. In the C++ Guild, deeply technical Working Groups collaborate to conduct in-depth exploration of current topics such as Reflection, Inter-Thread Communication, and API review, while others focus on community and organization, event planning, presentation, and project management. This variety ensures that every engineer can find a group that aligns with their own interests and career goals, and can also learn from the research and work of others. In addition, people can flexibly commit to join the Guild and participate when they have time or an interest in doing so. Everybody is welcome!

“The meetups and events organized and supported by the Guild have given me the opportunity to deepen my technical knowledge in C++ and other related areas. Being involved in the Conference Working Group has allowed me to mentor colleagues across the company. I feel like I am helping to create – while also being given – a comprehensive platform for both personal and professional growth.”

– Elena Vorobyeva

Jessica Winer is a Junior Software Engineer working on Bloomberg’s Asset and Investment Management (AIM) Enterprise product. She is responsible for creating a highly configurable automated user experience for Post Trade. She joined Bloomberg three years ago.

Tell us about how you got involved with the C++ Guild? How long were you at Bloomberg before you got involved with the community?
When joining Bloomberg, I was particularly drawn to the company’s “Choose your own adventure” style of career development. I’ve tried to take full advantage of a wealth of opportunities offered to me to have impact across the firm. I have been able to dive into the deep end of technical projects, have gotten lost in the weeds, and climbed my way out. And I’ve been able to take projects from ideas to reality even at this early stage of my career. My Team Lead pointed me towards guilds as an avenue for exposure and technical exploration. As a new member of the C++ Guild, I have gotten to work with engineers across the company.

What initiatives have you been actively involved in?
I have gotten involved in a few different working groups, such as the Recommended Libraries Working Group, where I learned about weighing the qualities of different tools to solve a specific technical problem.

As part of the Testing Working Group, I’ve learned about testing best practices across Bloomberg, and have contributed to tools to increase testing coverage. This group is particularly interesting to me, as I have been co-leading a local department working group for testing for over a year, where we have been creating a cross-department solution for Gherkin-style system tests which can be run automatically on a daily interval. Through the Guild, I realized that a lot of the questions we were deliberating in our department were already being discussed Bloomberg-wide.

Most recently I have been working in the Conferences Working Group, learning more about the organization of conferences and Bloomberg’s involvement externally.

Are there any conferences you have attended as a speaker or presented your work?
My first conference through Bloomberg was CppCon 2023, which is the world’s largest C++ conference. While I enjoyed learning from brilliant minds and expanding my knowledge in formal sessions, it was truly incredible to meet members of the C++ Standards Committee, who are helping to evolve the language, as well as Bjarne Stroustrup, who created the language. These people all went out of their way to welcome us into the community. After attending CppCon, I co-created a presentation on system design with a colleague, which we presented at ACCU 2024 in Bristol, UK.

What’s one thing you wish people knew about the Guilds?
Guilds are meant to be a learning opportunity for those at the company. You don’t already have to be a domain expert to join. You will become part of a network of brilliant engineers and domain expertise will follow.

In 2024, you attended CppCon. Why is it important for Bloomberg engineers to attend, participate in, and speak at technical conferences?
Conferences are a great opportunity to meet brilliant engineers both in and outside of Bloomberg. Attending conferences gives you dedicated time to learn from others and to improve your technical skills.

“When joining Bloomberg, I was particularly drawn to the company’s “Choose your own adventure” style of career development. I’ve tried to take full advantage of a wealth of opportunities offered to me to have impact across the firm. I have been able to dive into the deep end of technical projects, have gotten lost in the weeds, and climbed my way out. And I’ve been able to take projects from ideas to reality even at this early stage of my career.”

– Jessica Winer

Conor Spilsbury is a Senior Software Engineer within the Trade Automation and Execution organization, where he works on Bloomberg’s Listed Securities Execution Management System, EMSX, a real-time, high throughput, multi-asset transactional trading platform used by financial institutions around the world to manage their daily trading activity. He has worked at Bloomberg for five years, having joined as an entry-level engineer in the infrastructure team after finishing his master’s degree in mathematics. He is now working on deepening the integration between EMSX and AIM, our buy-side OMS, as part of Bloomberg’s enterprise offerings.

How did you get involved with the C++ Guild?
I am always looking for what more I can be doing – both in my own team and beyond. Six months after I joined Bloomberg, I read a post in one of the internal newsletters looking for help in organizing Guild activities. My managers at Bloomberg have always encouraged and supported me to participate.

The Guild is responsible for a C++ newsletter that is regularly sent to engineers at Bloomberg. We use this to share recent updates in the C++ community, including changes to our build tools, tooling or library updates, advertising upcoming conferences that engineers can attend, internal transfer opportunities, internal talks from Bloomberg employees or special guests (e.g., the C++ Guild recently hosted Sean Baxter to talk about the Circle Compiler), and ultimately highlighting opportunities for engineers to get involved in the C++ community itself.

The newsletter has been running for five years now and we still experiment with what we can include in it. For example, we’re also trying to do more to promote ways to contribute to “inner source” projects and have been running a “Feature of the Month” column which shares a tip about a C++ feature. The most recent newsletter included tips on C++23’s ‘std::expected’.

How did you become co-chair?
As the Guild has grown, we have expanded the domains that we work on, which means there are all kinds of new opportunities for engineers to get involved in. The Guild is organized into dedicated Working Groups, each of which is focused on a particular domain.

I found myself making contributions to multiple different WGs and have led two of them; I’ve contributed to API Reviews, Communications, Membership, Recommended Libraries, Testing, and organized our presence at an internal conference called “Guild Week” over multiple years, and even delivered talks at this conference.

One of the primary forms of responsibility for me in recent years has come from being involved in Membership and supporting new members to get involved. This has also led me to presenting talks about Guild to other internal communities at Bloomberg.

After a few years of making increasingly larger contributions across multiple working groups, I put myself forward to be the next chair of the Guild and I was fortunate to receive a lot of support.

What are some of the ways the C++ Guild’s members influence C++ utilization both within and outside the company ?
One of our goals is to bring engineers across the company together to work on influencing the direction of C++ at Bloomberg and improving the development experience internally. We do this by establishing best practices and guiding principles based on community feedback and contributions.

For example, our Tooling Working Group maintains and improves our tools for C++ development along with standardizing this tooling. They are currently working on implementing the Common Package Specification as described by our very own Bret Brown at CppCon 2023 in collaboration with KitWare.

In addition, Bloomberg has many active contributors to new features in the C++ programming language, and we have a Working Group that coordinates our efforts with the wider international standardization working group for C++, WG21. For example, Dan Katz, our previous Guild co-chair, is a co-author on the paper that proposes to add Reflection into C++26, which will be a major milestone for the language.

How has the C++ Guild community supported your career development?
I’ve been able to gain a lot more technical knowledge, including expert insights, best practices, and industry trends that have helped me deepen my understanding of the language and stay up-to-date with the latest developments both internally at Bloomberg and externally in the wider community.

Being involved in the Guild is also a unique opportunity to have company-wide impact and to gain leadership experience whilst remaining an individual contributor as opposed to going down a Team Lead or Management track. I’ve taken the lead in organizing Guild initiatives, setting direction, and mentoring others to achieve our goals. This experience has not only helped me become a more effective team player but also given me the confidence to take on new challenges in my own role. I’ve been able to bring this experience back to my team and make more meaningful contributions as a result.

The community has also provided me with opportunities to meet and connect with engineers in other departments, which has been a great way to expand my network and learn about new areas of the company. It’s amazing how often I’ve been able to find the exact person I need to answer a question or provide guidance.

I found this particularly useful when I was looking for a new challenge and decided to move teams internally to an entirely new domain. Thanks to the Guild, I had already established relationships with engineers who could offer valuable advice and introductions. As it turns out, the first time I met two of my current teammates in EMSX was when the three of us were attending CppCon, a C++ industry conference!

At CppCon 2024, I gave my first talk at a conference which was a really rewarding experience. In particular, collaborating with colleagues as we went back and forth improving the talk together.

How do you encourage employees to get involved?
Some engineers will join the Guild with a clear idea of what they want to work on, but others may not know where to start. In either case, the most important thing is to bring enthusiasm and a curiosity to learn more. To help with this, we have a Membership Working Group that pairs each new member with an experienced Guild member to support them. It all comes down to trying out new things, volunteering to get involved in an initiative, or pitching something new and sharing ideas.

Ultimately, the more perspectives represented by engineers in the Guild, the better. Our goal is to reach engineers across the entire company in all of our departments and at every experience level to improve their experience.

“Being involved in the Guild is also a unique opportunity to have company-wide impact and to gain leadership experience whilst remaining an individual contributor as opposed to going down a Team Lead or Management track.”

– Conor Spilsbury