Title: Principal Software Engineer Company: Rocket Tech Location: Newbury, United Kingdom

Location: Newbury, United Kingdom Employment: Full time

It's fun to work in a company where people truly BELIEVE in what they're doing!

Job Description Summary: The Infrastructure Modernization business unit is seeking a highly experienced Principal Software Engineer to join our engineering organization and provide deep technical leadership across our COBOL development ecosystem and our Enterprise Server application replatforming products. This is a hands-on, strategic role focused on designing, building, and evolving mission-critical infrastructure used by global enterprises running high-volume, high-reliability systems.

In this role, you will influence architecture across multiple product lines, guide engineering best practices, and help define the future of our platform as customers modernize decades-old workloads into more agile, distributed and environments. You will partner closely with senior engineering leaders, product managers, and domain experts to drive innovation at scale.

What You’ll Do

Technical Leadership

Architect, design, and implement core components within our COBOL development tools, runtime environments, and mainframe replatforming infrastructure.
Provide technical direction across multiple engineering teams building compilers, runtimes, middleware, and large-scale distributed systems.
Drive modernization strategies for legacy application ecosystems, including cloud migration, workload transformation, and hybrid deployment scenarios.

Hands-On Engineering

Own complex technical domains end-to-end, from design through production, balancing long-term architecture with immediate product needs.
Build highly reliable, scalable, and secure infrastructure software used in mission-critical enterprise environments.
Conduct deep code reviews, troubleshoot production issues, and mentor engineers in system-level design and performance optimization.

Cross-Functional Impact

Collaborate with product management to shape roadmap priorities and translate customer challenges into technical solutions.
Work with System Test, DevOps, and release engineering to ensure high-quality, low-risk releases across a diverse product portfolio.
Introduce and champion engineering excellence practices, including automated testing, performance benchmarking, observability, and maintainability.

What We’re Looking For

Required Experience

10+ years of professional software engineering experience, including leadership over complex, multi-team technical initiatives.
Deep expertise in systems-level software development, such as compilers, runtimes, operating systems, or infrastructure-level platforms.
Strong background in mission-critical, high-availability software (e.g., financial services, telecom, government, or core enterprise platforms).
Demonstrated experience with COBOL, PL/I, C, or C++—or significant experience in other lower-level languages with a willingness to dive into COBOL domain internals.
Proven track record building or modernizing enterprise-grade tooling, middleware, or distributed systems.
Ability to decompose legacy architectures, assess modernization paths, and design scalable solutions.

Preferred Qualifications

Experience with mainframe-to-cloud migration, workload replatforming, or runtime compatibility layers.
Familiarity with Azure, AWS, or hybrid cloud architectures.
Understanding of static and dynamic language runtimes, compiler pipelines, and virtual machine internals.
Prior technical mentorship or architectural leadership spanning multiple scrum teams.
Strong diagnostic skills for debugging low-level performance, memory, concurrency, or runtime issues.

Who You Are

A pragmatic engineer who balances ideal architecture with real-world constraints.
Passionate about long-term maintainability and operational excellence.
Comfortable working with legacy systems and excited about evolving them for the future.
A collaborator who elevates teams through mentorship and cross-functional alignment.
Someone who thrives in a technically rich, complex domain where your expertise has large-scale impact.

Why Join Us?

Influence the future of mission-critical modernization technologies used worldwide.
Work with a highly experienced engineering organization with deep domain expertise.
Opportunity to shape architecture and product direction across multiple major portfolios.
A culture that values technical depth, thoughtful engineering, and long-term product stewardship.

Rocket Software Inc. is committed to creating a diverse environment and is proud to be an equal opportunity employer. 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. Rocket Software Inc. is also committed to compliance with all fair employment practices regarding citizenship and immigration status.

At Rocket Software, we believe AI is a critical enabler of innovation and productivity. All Rocketeers are expected to actively leverage AI-powered tools and technologies, where appropriate, to enhance efficiency, improve decision-making, and deliver greater impact in their roles. Embracing continuous learning and the responsible use of AI is an essential part of how we work.

As part of our commitment to a safe and trustworthy workplace, we include background and reference checks in our hiring process.

Rocket is committed to working with and providing reasonable accommodation to individuals with physical and mental disabilities. If you need special assistance or an accommodation while seeking employment, please call: recruiter contact or send an email to recruiter contact. We will make a determination on your request for reasonable accommodation on a case-by-case basis.

If you like wild growth and working with happy, enthusiastic over-achievers, you'll enjoy your career with us!