Lead Software Developer, Costar Group - London

CoStar Group, Inc.; Greater London; On-site; GBP 70,000 - 90,000; Full time

Job summary

A leading technology company in Greater London is seeking a Lead Software Developer to drive innovation in software development. The ideal candidate will have significant experience in .NET development and SQL Server, collaborating closely with cross-functional teams. The role includes mentoring junior developers and working on large-scale systems. This position offers comprehensive benefits, including 28 days of annual leave and a competitive pension.

Benefits

Full private medical coverage

28 days annual leave

Competitive pension

Qualifications

• 5+ years of .NET development (C#) with cross-platform communication.
• Experience with SQL Server including writing queries and data pipeline engineering.
• Hands-on experience with cloud-based databases.

Responsibilities

• Understand business drivers for software development.
• Design, architecture, and development activities for applications.
• Mentor other developers and foster knowledge sharing.

Skills

C#

.NET Framework

SQL Server

AWS

Python

API development

ETL/data pipeline engineering

Databricks

Education

Bachelor’s Degree or equivalent experience

Tools

Jupyter Notebook

NoSQL databases

Job description

Lead Software Developer, Costar Group - London

Overview

CoStar Group (NASDAQ: CSGP) is a leading global provider of commercial and residential real estate information, analytics, and online marketplaces. Included in the S&P 500 Index and the NASDAQ 100, CoStar is on a mission to digitize the world’s real estate, empowering people to discover properties, insights and connections that improve their businesses and lives. With over 35 years of experience, we create uniquely valuable offerings and continuously drive innovation for our customers, employees, and investors.

Responsibilities

• Deeply understand what drives the business for which you are building software.
• Hands‑on involvement in design, architecture, and development activities for applications across the Research Process.
• Work on large, distributed, API‑driven systems that handle massive data volumes and high transaction rates for tens of thousands of users, ensuring bullet‑proof, efficient, and maintainable code using C#, .NET Framework, Python, JSON, SQL Server, AWS and Databricks.
• Collaborate with QA resources to deliver fully tested, defect‑free software.
• Act as a key member of the product launch team and work closely with DevOps to resolve operational issues.
• Deliver work products that meet specifications and exhibit optimal performance.
• Mentor other developers and facilitate knowledge sharing.

Qualifications

• Bachelor’s Degree or equivalent experience.
• 5+ years of .NET development (C#) with cross‑platform communication technologies such as Web API.
• 3+ years with SQL Server, including writing queries, data matching/cleansing/enriching, and ETL/data pipeline engineering.
• Track record of building and launching successful products that leverage terabytes of data.
• Ability to analyze technical requirements and design new architectures, data models, and ETL strategies.
• Expertise in database design, complex T‑SQL programming, performance tuning, and index analysis.
• Hands‑on experience with cloud‑based relational and non‑relational databases.
• Facilitate discussions among developers to introduce innovative technologies.
• Evaluate emerging technologies for opportunities, trends, and best practices to strengthen CoStar’s platform.
• Experience with .NET Core, Python, Jupyter Notebook, AWS, and NoSQL databases.
• Experience with Databricks and Lakehouse architecture.

Benefits

• Full private medical, dental and life assurance coverage.
• 28 days annual leave and a competitive pension.
• Season ticket loans, enhanced maternity and paternity pay.
• Work culture of collaboration and innovation in our UK hubs, including the Blue Fin.

CoStar Group is an Equal Employment Opportunity Employer; we maintain a drug‑free workplace and perform pre‑employment substance abuse testing. All qualified applicants will receive consideration for employment without regard to race, color, religion, gender, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status.