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Principal Software Engineer (.NET, C#, XAML)

Fidelity

Fidelity

Software Engineering
Boston, MA, USA
Posted on Sep 18, 2025
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Job Description:

Software Engineer – Digital Experience

Are you interested in serving the needs of millions of customers by building the best-in-class digital experience that helps them in financial planning, investing, and retirement solutions? Our chapter comprises teams that work on desktop applications and platforms like Active Trader Pro®. We're looking for product-aware engineers who are passionate, inquisitive, and responsible individuals to help us on our mission to deliver the best user experience to our customers.

The Purpose of Your Role

Our teams build and contribute to Fidelity’s digital presence. As a desktop developer, you will help us build the desktop user experience and the underlying platforms needed to support our digital presence. You’ll work on building end to end features as part of our autonomous, cross functional teams. You’ll have the opportunity to contribute to own entire features from concept to deployment working on cross-functional teams. You'll have the opportunity to contribute ideas to improve our products as well as develop your skills, learn new technologies and languages, and continue to learn. We're looking for highly motivated individuals who work well in a collaborative, iterative, and fast-paced environment.

The Expertise We’re Looking For

You have a passion for technology and can navigate your way across complex and rapidly-changing landscapes by staying on top of latest trends and thrive by sharing knowledge.

Are a creator, a doer, and a disruptor who will help us solve real-life problems and meet real customer needs. You’ll be helping us build things, taking an idea, and creating rapid prototypes that are shippable and learn from real-life feedback.

Are comfortable to be a self-starter, who actively challenges status-quo, is curious and not afraid to ask 'Why' and 'What if'?

Are experienced with the tools of the trade including a variety of modern programming languages and frameworks

Care about cycle time and use CI/CD practices, tools to rapidly deploy changes to customers while minimizing risk using practices like A/B tests, blue-green deployments, and feature toggles

Stay on top of Algorithms, Data Structures and Design Patterns and love the challenge of building highly scalable systems that can support thousands of transactions/sec.

Have a mindset of test first development and are experienced in modern test frameworks. We believe in testing and that quality is everyone’s job.

Are data-driven and can measure, collect and use data to make decisions. We understand the value of intuition and the need to balance decisions accordingly.

Have strong communication skills and technical expertise to drive and participate in meaningful discussions.

The Skills You Bring

  • Strong knowledge of HTTP based APIs, Networking and how the internet works.
  • Strong .Net/C# based applications expertise desired
  • Strong experience with application frameworks
  • Experience with Azure DevOps or GitHub repository/pipelines & tools
  • Experience with performance tuning & memory utilization of desktop applications
  • Comfortable with Visual Design & Rapid Prototyping
  • Expert at one IDE of choice (Visual Studio, WebStorm)
  • Unit testing & Automation Tools/Frameworks (MS Unit, NUnit, xUnit)
  • API Design & Development, MicroServices Architecture.
  • DevOps, Automated Testing and Continuous Delivery

How Your Work Impacts the Organization

We believe that diversity in background and experience will foster an inclusive and engaging work environment for our employees. This ultimately enables us to deliver a better product for our customers.

Being technically competent is only telling half the story. We believe that delivering the best possible customer experience requires an artful blend of human ingenuity and technology. While we value smart technologists, we are fanatics about our culture that promotes autonomy and leadership at all levels. People who are great cultural fits demonstrate curiosity to learn, are unafraid to break things, step up and take the lead, take ownership of their projects, and thrive by sharing knowledge.

Our culture code is simple

  • We share knowledge to empower and connect everyone
  • We live outside our comfort zone.
  • We believe life is too short to not love what you do
  • We know amazing people create great opportunities
  • We are customers.
  • We favor autonomy and take ownership

Certifications:

Category:

Information Technology

Most roles at Fidelity are Hybrid, requiring associates to work onsite every other week (all business days, M-F) in a Fidelity office. This does not apply to Remote or fully Onsite roles.

Please be advised that Fidelity’s business is governed by the provisions of the Securities Exchange Act of 1934, the Investment Advisers Act of 1940, the Investment Company Act of 1940, ERISA, numerous state laws governing securities, investment and retirement-related financial activities and the rules and regulations of numerous self-regulatory organizations, including FINRA, among others. Those laws and regulations may restrict Fidelity from hiring and/or associating with individuals with certain Criminal Histories.

Company overview

At Fidelity, we are passionate about making our financial expertise broadly accessible and effective in helping people live the lives they want! We are a privately held company that places a high degree of value in creating and nurturing a work environment that attracts the best talent and reflects our commitment to our associates. We are proud of our diverse and inclusive workplace where we respect and value our associates for their unique perspectives and experiences. For information about working at Fidelity, visit FidelityCareers.com. Fidelity Investments is an equal opportunity employer. Fidelity will reasonably accommodate applicants with disabilities who need adjustments to complete the application or interview process.

If you would like to request an accommodation, please contact us at:

accommodations@fmr.com

Apply

Join us

At Fidelity, you’ll find endless opportunities to build a meaningful career that positively impacts peoples’ lives, including yours. You can take advantage of flexible benefits that support you through every stage of your career, empowering you to thrive at work and at home. Honored with a Glassdoor Employees’ Choice Award, we have been recognized by our employees as a top 10 Best Place to Work in 2024. And you don’t need a finance background to succeed at Fidelity—we offer a range of opportunities for learning so you can build the career you’ve always imagined.

Fidelity's working model blends the best of working offsite with maximizing time together in person to meet associate and business needs. Currently, most hybrid roles require associates to work onsite all business days of one assigned week per four-week period (beginning in September 2024, the requirement will be two full assigned weeks).

We invite you to Find Your Fidelity at fidelitycareers.com.

Fidelity Investments is an equal opportunity employer. We believe that the most effective way to attract, develop and retain a diverse workforce is to build an enduring culture of inclusion and belonging.

Fidelity will reasonably accommodate applicants with disabilities who need adjustments to participate in the application or interview process. To initiate a request for an accommodation, contact the HR Accommodation Team by sending an email to accommodations@fmr.com, or by calling 800-835-5099, prompt 2, option 3.

At Fidelity, we value honesty, integrity, and the safety of our associates and customers within a heavily regulated industry. Certain roles may require candidates to go through a preliminary credit check during the screening process. Candidates who are presented with a Fidelity offer will need to go through a background investigation and may be asked to provide additional documentation as requested. This investigation includes but is not limited to a criminal, civil litigations and regulatory review, employment, education, and credit review (role dependent). These investigations will account for 7 years or more of history, depending on the role. Where permitted by federal or state law, Fidelity will also conduct a pre-employment drug screen, which will review for the following substances: Amphetamines, THC (marijuana), cocaine, opiates, phencyclidine.

Benefits
Learning & development
Culture

Benefits that adapt to everything life sends your way

401(k) with company match

Medical, dental, vision and prescription drug coverage

16-week maternity leave & 12-week parental leave

Student loan assistance

Fidelity is invested in you

Committed to Professional Development

At Fidelity, we are constantly adapting to the changing needs of our customers, new technologies, and better ways of working. And we empower our employees to do the same, with an emphasis on developing skills and connections that will help propel you forward in your career while being able to make an impact for Fidelity’s customers around the world.

We offer a wide range of options for professional development including online, in-person, and mentor driven solutions. Special interest and networking groups are also part of our culture of empowerment, personal and professional enrichment, diversity and inclusion, and knowledge sharing.

Continuing Education & Training

  • Assess, build, and align your development plan through resources like our skill-building classroom and online courses.
  • Video-based training for technology, leadership, management & more.
  • Ongoing skills development and coaching opportunities.
  • Paid training with a facilitator who is dedicated to your onboarding and will track and evaluate your progress, giving you strategies to improve.
  • A range of talent development programs to support career mobility.

Mentoring

  • Utilize the skills of experienced leaders to enrich your career.
  • Dedicated mentors to help you grow into new areas of Fidelity’s business as you develop new skills.
  • An open atmosphere of knowledge sharing and collaboration.
  • Opportunities to pay it forward, sharing the knowledge you develop and as you help others define how they want their career to take shape.

Our Commitment

Discover opportunities to build a fulfilling career within a supportive culture that celebrates individuality. We empower our associates to pursue career paths that align with their unique goals and personalities.

Giving back to our communities

Throughout Fidelity, you’ll find a genuine commitment to social responsibility – where we strive to make an impact for customers, while also making an impact on the world.

Fidelity Cares

  • Provides associates with opportunities to actively volunteer and share their talents.
  • Hosts numerous company-wide volunteer events (in-person and virtual).
  • Partners with nonprofit organizations to support our local communities.
  • More than 12,500 associates donate time annually – from interns to SVPs.
  • Impact includes refurbishing schools, donating books and supplies, and teaching financial literacy.

Fidelity Charitable®

  • Created to make it easy for people to support charitable organizations they care about.
  • Helped deliver $14.9billion in donor-recommended grants to charity in 2024.
  • Supported more than 433,000 unique charities around the world.
  • Since its inception, more than $100 billion has been given to public charities.

Technology careers at Fidelity

Imagine and create the next generation of financial products and tools.

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