Senior Software Engineer

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Xpansiv®, a trailblazer in the energy and environmental commodities market, operates the integrated, open, and neutral market platform designed to accelerate the global energy transition. Xpansiv provides thousands of market participants and intermediaries with access to the widest possible range of energy transition markets, through its suite of solutions, including the world's largest environmental commodities trading platform, where billions of assets cross per year. Xpansiv's end-to-end technology platform services the entire life cycle of environmental commodities, connecting diverse markets and market participants across the world and enabling stakeholders to deliver transparent and trusted environmental claims to address the growing demand for energy transition. Leveraging its extensive industry knowledge and proven technology portfolio, Xpansiv assists companies seeking to identify and mitigate risk, streamline the management of their environmental assets, and comply with regulations, caps and commitments.

Position Summary:

We are seeking a Senior Software Engineer with experience in both Microsoft (modern and legacy) technologies and PHP. In this hybrid support/development role, you'll be the go-to expert for maintaining, troubleshooting, and extending mission-critical financial systems built on older tech stacks-while also interfacing with modern infrastructure. You will own this particular project and the team that maintains the development function for this application.

Essential functions:

• Develop secure, performance optimized and scalable code that is well tested and documented
• Provide ongoing support, maintenance, and debugging for legacy applications in production.
• Collaborate with development and DevOps teams to ensure stable deployment and operation of all systems.
• Investigate and resolve performance, stability, and integration issues.
• Write and optimize advanced SQL Server queries, stored procedures, and indexing strategies.
• Contribute to basic cloud administration.
• Understand and work within complex financial domain requirements, including compliance and security.
• Take ownership of the product and mentor junior staff.
• Participate in engineering efforts across the business as needed, primarily supporting PHP applications.

Required Qualifications:

• B.S./M.S. in Computer Science or equivalent relevant experience
• 5+ years experience building web applications
• Strong proficiency with .NET Framework and modern .NET.
• Strong proficiency with Entity Framework.
• Proficiency with ASP.NET Web Forms and ASP.NET Web API.
• Experience with PHP
• Experience writing and debugging JavaScript
• Experience mentoring and leading a small team of development engineers.
• Expertise with SQL Server and PostgreSQL, including advanced features such as:
• Query optimization
• Indexing strategies
• Views, triggers, functions, and stored procedures

Preferred Qualifications:

• Experience with modern frameworks such as .Net Core, ASP.NET Core and Entity Framework Core, as well as DevExtreme
• Experience with basic cloud infrastructure (preferably GCP, but AWS or Azure acceptable).
• Experience with Vue.js and DevExpress
• Familiarity with CI/CD workflows and deployment pipelines is a plus.
• Finance industry experience and understanding of financial products, regulations, or transaction workflows is a major advantage

What can you expect throughout the interview process:

Step 1- Shortlisting of resume + recruiter screening

Step 2- Technical take-home Assessment

Step 3- Technical Interview with Engineers

Step 4- Final interview with key stakeholders

Base Salary

Compensation for this role will vary among specific regions due to geographic differentials in the labor market, actual pay will be determined considering factors such as relevant skills and experience, knowledge, education and training. However, compensation in the following regions is expected to be as follows:

London: Compensation is expected to be between

£85,000-£100,000

Here at Xpansiv, we cultivate diversity, celebrate individuality, and believe unique perspectives are key to our collective success in building trust and transparency in global efforts toward net-zero future. Xpansiv is committed to equal employment opportunity regardless of race, color, religion, gender, sexual orientation, gender identity or expression, national origin, age, disability, genetic information, protected veteran status, or any status protected by applicable federal, state, or local law.

Note to Recruiters: Xpansiv does not accept unsolicited resumes or referrals from placement agencies, staffing vendors or other external parties seeking recruiting fees without a signed formal agreement.

We may use artificial intelligence (AI) tools to support parts of the hiring process, such as reviewing applications, analyzing resumes, or assessing responses. These tools assist our recruitment team but do not replace human judgment. Final hiring decisions are ultimately made by humans. If you would like more information about how your data is processed, please contact us.