C# Software Engineer - Fixed Income Job at Harrington Starr (London)

Principal Quantitative Developer

Fidelity’s Asset Management Technology division is seeking a Senior Quantitative...

Location

United States , Jersey City; Merrimack

Salary:

97000.00 - 185000.00 USD / Year

Fidelity Investments

Expiration Date

Until further notice

Requirements

Bachelor’s degree in a quantitative field such as Financial Engineering, Physics, Applied Mathematics, Computer Science, or a closely related discipline
at least six (6) years of experience as a Senior Quant Developer or in a similar role
experience in quantitative analytics, ideally in the fixed income market, including interest rate modeling and interest rate derivatives
strong skills in quantitative finance, with an emphasis on applying numerical methodologies to financial problems, including finite-difference methods for PDE solvers, tree models, Monte Carlo simulation, and optimization techniques for curve fitting
deep understanding of probability theory, linear regression, and time-series analysis
expert-level software engineering skills in C++
proficiency in Python, shell scripting, SQL, and Linux (preferably in a command-line environment)
strong proficiency in object-oriented programming (OOP) principles and hands-on experience implementing design patterns in production code
full-stack software development knowledge and critical thinking skills to design optimal solutions for high-performance fixed income analytics
experience with cloud technologies, particularly AWS, and container orchestration platforms such as EKS

Job Responsibility

Gathering ideas, conceptualizing them through a programming language, and creating a packaged solution that can be used by investment professionals
building high quality, robust, efficient, and scalable analytical solutions that directly support portfolio construction, risk management, and alpha generation
improving the quality and time-to-market of Research initiatives through a combination of both analytical and software development skillsets

What we offer

Comprehensive health care coverage
emotional well-being support
market-leading retirement
generous paid time off and parental leave
charitable giving employee match program
educational assistance including student loan repayment, tuition reimbursement, and learning resources to develop your career

Fulltime

Quantitative Analyst

Citigroup Global Markets Inc. seeks a Quantitative Analyst for its New York, New...

Location

United States , New York

Salary:

160000.00 - 175000.00 USD / Year

Citi

Expiration Date

Until further notice

Requirements

Master’s degree, or foreign equivalent, in Mathematics, Computer Science, Operations Research and Information Engineering, Financial Engineering, or related field
2 years of experience as a Quantitative Analysis Program Analyst, or related position involving quantitative model development and risk management support in a global financial services institution
Using mathematical methods, including advanced calculus, statistics, probability and stochastic processes, in security pricing and financial modeling projects
Applying numerical analysis techniques to perform fast calculations on large datasets
Software development in Python and C++
Maintaining and implementing high performance time series analysis and processing tools using C++
Functional programming and objected oriented programming
Producing models and analytics using machine learning methods
Big data management including cleaning, storage and delivery of large unstructured datasets and creating and maintaining databases and pipelines
Fixed income and derivative securities pricing across multiple asset classes

Job Responsibility

Develop analytical libraries used for pricing, hedging, liquidity management and risk management
Create, implement and support quantitative models for the trading business
Develop optimization tools for constructing interest rate curves and computing single currency and cross currency asset swap spreads, optional-adjusted spreads and coupon adjusted spreads
Generate trading signals based on the spreads to select the optimal trades with rigorous back-tests and portfolio optimization
Carry out post-trade analyses on rebalancing and risk management methodologies
Develop and maintain a range of Excel and React based web tools to support the trading and sales desks to price, trade and hedge a range of fixed income securities
Develop and maintain monitoring tools to ensure the marks and computed risks are accurate and tradable
Conduct quality control and compliance checks to ensure the accuracy and completeness of the streaming intraday ticking market data and end-of-day data
Perform data processing tasks to collect, process, and analyze data from the macroeconomic data, fixed income market data, and publicly available fixed income trade records
Generate real-time alerts and reports to support the sales and trading business

What we offer

medical, dental & vision coverage
401(k)
life, accident, and disability insurance
wellness programs
paid time off packages, including planned time off (vacation), unplanned time off (sick leave), and paid holidays
discretionary and formulaic incentive and retention awards

Fulltime

Credit Quantitative Analyst

We are seeking a highly skilled and experienced VP Quantitative Analyst to join ...

Location

United States , New York

Salary:

175000.00 - 250000.00 USD / Year

Citi

Expiration Date

Until further notice

Requirements

A Master's degree or higher in a quantitative field such as Mathematics, Physics, Financial Engineering, or Computer Science is preferred
4-5 years of experience in a comparable quantitative modeling or analytics role, ideally focused on Fixed Income Products and Markets
Expert-level programming skills in C++ for a production environment
Strong proficiency in Python for analytics, tooling, and data analysis
Deep understanding of probability theory, stochastic calculus, and numerical methods used to evaluate complex financial instruments
Solid foundation in software design principles and best practices
Demonstrable knowledge of fixed income markets, products and conventions as well as quantitative methods
Consistently demonstrates clear and concise written and verbal communication skills, with the ability to be a team player and explain complex concepts to diverse audiences

Job Responsibility

Design, develop, and implement sophisticated mathematical models for credit contingent securities and numerical methods
Implement and maintain the models, robust and efficient numerical methods for pricing, valuation, and risk management within the existing C++ quantitative library
Enhance and maintain the analytics infrastructure, ensuring the high performance, accuracy, and scalability of all models
Collaborate closely with trading, structuring, and technology teams to understand business requirements and deliver cutting-edge quantitative solutions
Provide expert quantitative support to front-office teams on credit contingent securities and structures
Design and maintain Python-based tools and solutions to empower traders with new trade pricing, scenario analysis, and risk management capabilities
Conduct thorough model testing, validation, and documentation to meet rigorous internal standards and regulatory requirements
Work in close partnership with control functions such as Financial Control, Compliance, Model Validation, Market and Credit Risk, and Audit to ensure an appropriate governance and control infrastructure
Appropriately assess risk when business decisions are made, demonstrating particular consideration for the firm's reputation and safeguarding Citigroup, its clients, and assets
Drive compliance with applicable laws, rules, and regulations, adhering to all policies and applying sound ethical judgment

What we offer

medical, dental & vision coverage
401(k)
life, accident, and disability insurance
wellness programs
paid time off packages, including planned time off (vacation), unplanned time off (sick leave), and paid holidays

Fulltime

Software Engineer – Credit

Optiver is seeking Software Engineers specializing in US corporate bond and cred...

Location

United States , New York

Salary:

200000.00 USD / Year

Optiver

Expiration Date

Until further notice

Requirements

Strong engineering instincts and a deep understanding of computer science fundamentals
Programming experience across C++ or C with other object-oriented languages also considered
Experience optimizing high-throughput systems that must process and react in real-time to streams of pricing and trade data
Familiarity with the market microstructure and trading domain for US corporate credit markets, fixed income ETFs, and/or credit derivatives (CDS, CDX indices)
Experience with connectivity to electronic trading venues and FIX protocol for credit markets
Readiness to set technical direction, promote strong engineering principles and continuously seek ways to refine and optimize systems in a fast-moving, ever evolving environment
Excellent communication skills and the ability to work effectively in a fast-paced, collaborative environment with traders, researchers, and other technologists.

Job Responsibility

Help establish the vision and technical direction for major credit trading initiatives
Design, develop, support, and maintain large portions of our credit trading infrastructure, including request for quote (RFQ) trading platforms, create/redeem platforms, portfolio trading systems, order management systems (OMS), and execution management systems (EMS)
Contribute to our pricing, research and trading models that power our market-making and proprietary trading strategies
Collaborate deeply with traders and researchers to directly solve the trading problem and build the business
Be a part of 0 to 1.

What we offer

The opportunity to work alongside best-in-class professionals from over 40 different countries
Highly competitive compensation package
Global profit-sharing pool and performance-based bonus structure
Ownership over initiatives that directly solve business problems
401(k) match up to 50% and fully paid health insurance
25 paid vacation days alongside market holidays
Extensive office perks, including breakfast, lunch and snacks, regular social events, clubs, sporting leagues and more.

C#.NET Software engineer - Trading applications

Talan is seeking a proactive and skilled Full-Stack Application Developer to joi...

Location

United States , New York

Salary:

110000.00 - 160000.00 USD / Year

Talan

Expiration Date

Until further notice

Requirements

Bachelor’s in Computer Science, Engineering, Finance, or similar
5+ years of relevant experience in Front Office or financial services background
Knowledge of Fixed Income & Capital Markets
Exposure to pricing or risk analytics
Strong OOP and .NET/C# development
Solid grasp of design patterns, Dependency Injection, Entity Framework
Proficient in SQL and relational databases
Familiar with scripting (e.g., Python, PowerShell)
Experience with Git and CI/CD in Agile environments

Job Responsibility

Design, develop, and support real-time pricing and analytics tools for Fixed Income trading (full stack)
Act as a key point of contact for front-office users (traders, sales, quants)
Gather business requirements and translate them into technical specifications
Own software delivery, maintenance, and support across all levels (L1–L3)
Collaborate with global teams to adapt and deploy tools
Follow Agile methodologies and CI/CD best practices

What we offer

401(k) retirement plan with company matching
15 days of paid vacation per year at hire and up to 27 according to seniority (annual untaken vacation days are cashed out)
8 paid holidays + 5 sick days + 2 personal days per year
Company health, dental, and vision insurance plans + FSA
Voluntary STD and LTD
Commuter/transit benefits

Fulltime

C#.NET Software engineer - Trading applications

Talan is seeking a proactive and skilled Full-Stack Application Developer to joi...

Location

United States , New York City

Salary:

110000.00 - 160000.00 USD / Year

Talan

Expiration Date

Until further notice

Requirements

Bachelor’s in Computer Science, Engineering, Finance, or similar
5+ years of relevant experience in Front Office or financial services background
Knowledge of Fixed Income & Capital Markets
Exposure to pricing or risk analytics
Strong OOP and .NET/C# development
Solid grasp of design patterns, Dependency Injection, Entity Framework
Proficient in SQL and relational databases
Familiar with scripting (e.g., Python, PowerShell)
Experience with Git and CI/CD in Agile environments

Job Responsibility

Design, develop, and support real-time pricing and analytics tools for Fixed Income trading (full stack)
Act as a key point of contact for front-office users (traders, sales, quants)
Gather business requirements and translate them into technical specifications
Own software delivery, maintenance, and support across all levels (L1–L3)
Collaborate with global teams to adapt and deploy tools
Follow Agile methodologies and CI/CD best practices

What we offer

401(k) retirement plan with company matching
15 days of paid vacation per year at hire and up to 27 according to seniority (annual untaken vacation days are cashed out)
8 paid holidays + 5 sick days + 2 personal days per year
Company health, dental, and vision insurance plans + FSA
Voluntary STD and LTD
Commuter/transit benefits

Fulltime

Fixed Income eTrading Connectivity – Senior Developer

The Fixed Income Connectivity team globally supports connectivity and routing so...

Location

United Kingdom , London

Salary:

Not provided

Citi

Expiration Date

Until further notice

Requirements

Extensive hand-on coding expertise in C+++ and Core Java, Mult-threading and Concurrency
Strong focus on system performance tuning and experience with low latency programming techniques
Strong academic record, ideally with a Bachelors or Masters degree in Computer Science, engineering or related technical or quantitative discipline
Demonstrable success in designing and delivering complex applications
Strong software development fundamentals, data structures, design patterns, Object-Oriented programming, architecture, algorithms, and problem-solving skills
Solid understanding of service architecture and high performance, low latency, and multithreading techniques
Experience of developing market connectivity applications is highly desirable
Prior experience in building e-trading systems is highly desirable
Knowledge of any financial products like Interest Rates, Spread Products, FX, Equities or Futures (e.g. bonds, interest rate swaps, repos) is highly desirable
Technical skills include Java, Spring, FIX, Aeron, Solace, Chronicle, TDD, BDD, KDB, REST, Gradle, Git and Unix Scripting

Job Responsibility

Designing and developing front office eTrading applications for the trading business
Understanding of good design principles and ability to adhere to complex design
Development of common, reusable components and services utilizing Citi’s best practices
Responsible for creating high performance, low latency applications leveraging existing Citi frameworks
Ensuring strong reliability, scalability and performance of the core application components
Drive architecture and execute on our technical strategy while partnering with various technology teams and to continue to evolve technical architecture roadmap beyond near term objectives
Coordinate development with both internal technology teams and Traders, Sales, and Quants
Driving engineering standards and continuing to strive for best – whilst utilizing creativity and innovation to improve the technical capabilities of the platform and ensuring it remains stable, flexible, and maintainable
Troubleshooting challenging performance and scalability issues
Assisting in third line support during core trading hours while working with other e-Trading teams to manage and support the applications

What we offer

27 days annual leave (plus bank holidays)
A discretional annual performance related bonus
Private Medical Care & Life Insurance
Employee Assistance Program
Pension Plan
Paid Parental Leave
Special discounts for employees, family, and friends
Access to an array of learning and development resources

Fulltime

Applied AI Researcher

Location

Poland , Warszawa

Salary:

180.00 - 200.00 PLN / Hour

Devire

Expiration Date

Until further notice

Requirements

An advanced degree (MSc or PhD) in fields such as Computer Science, Machine Learning, Mathematics, Statistics, Physics, Engineering, Quantitative Finance, or comparable hands-on industry experience
At least 4 years of professional experience showcasing strong domain expertise
Significant background in building and maintaining software solutions that support quantitative investment processes across equities, fixed income, or multi-asset portfolios
Solid command of modern programming languages, including Python, C++, and Java
Excellent communication skills in English

Job Responsibility

Work closely with team members to enhance and scale live machine learning systems and related applications
Design, prototype, and evaluate AI/ML-driven solutions through research and experimentation
Write, validate, and support robust, production-grade software with a strong focus on quality
Provide technical direction by leading initiatives that span multiple teams
Build and maintain reusable libraries and frameworks that ensure system reliability and testability

What we offer

Private HealthCare
Sports card
Life insurance
Working for a leading corporation with a stable market position
Working in the international environment
Hybrid work (3 days a week office work) with supportive and positive environment

Fulltime

C# Software Engineer - Fixed Income

Harrington Starr

Location:
United Kingdom , London

Category:
IT - Software Development

Contract Type:
Not provided

Salary:

Job Description:

Job Responsibility:

Requirements:

Additional Information:

Job Posted:
March 01, 2026

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Location:United Kingdom , London

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Job Description:

Job Responsibility:

Requirements:

Additional Information:

Job Posted:March 01, 2026

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