Senior Software Engineer I

About the role

Thought Machine is replacing legacy banking systems with modern, cloud-native core and payments technology. We are seeking a senior engineer to manage ambiguous, complex technical challenges and influence our long-term architectural roadmap. In this capacity, you will own the design and execution of critical platform components that underpin financial workflows. You will partner closely with product and engineering teams to translate business objectives into resilient technical strategies. The role requires you to navigate evolving requirements while maintaining a clear vision for sustainable software architecture. You will be instrumental in shaping the standards that define how our services perform, secure, and scale in production. Your work will directly impact the reliability and innovation velocity of the core banking ecosystem.

Key facts

What you'll do

• Architect solutions for intricate problems while setting standards for performance, security, and scalability across distributed systems.
• Oversee the end-to-end delivery of high-complexity projects that may span multiple departments and require cross-functional coordination.
• Drive the adoption of new technologies and AI tools to improve developer velocity, code quality, and operational insights.
• Investigate and resolve complex production issues across clusters and services to improve operational processes and reduce risk.
• Mentor senior engineers and conduct technical interviews for subject matter experts and leadership candidates to uphold engineering excellence.
• Align technical strategy with company objectives while managing expectations across senior leadership and external stakeholders.
• Collaborate with product managers to refine requirements and translate business needs into technical specifications that guide implementation.
• Evaluate existing codebases and infrastructure to identify opportunities for optimization, refactoring, and long-term maintainability.
• Facilitate design discussions that balance trade-offs between speed, robustness, and scalability in line with business priorities.
• Contribute to the definition of best practices, coding standards, and engineering guidelines that ensure consistency across teams.
• Support the deployment and monitoring of releases to ensure smooth transitions and minimal disruption to banking operations.
• Analyze system metrics and feedback to inform decisions that enhance the stability and performance of critical services.
• Act as a technical advisor to peers and stakeholders, providing clarity on feasibility, risk, and implications of proposed solutions.
• Champion continuous improvement initiatives that foster a culture of learning, experimentation, and accountability within the engineering organization.

Requirements

• Proficiency in modern backend programming languages, specifically Go or Python, with demonstrated ability to write clean, efficient, and maintainable code.
• Experience building and maintaining large-scale, cloud-native systems that operate reliably in distributed environments.
• Proven track record of technical leadership and mentoring peers through code reviews, design discussions, and knowledge sharing.
• Ability to solve undefined, high-complexity problems and influence departmental strategy through analytical thinking and clear communication.
• Extensive background in managing production operations across multiple environments, including development, staging, and live systems.
• Exceptional communication skills for stakeholder management, translating technical concepts into actionable insights for non-technical audiences.
• Strong understanding of software development lifecycle practices, including version control, testing, and deployment pipelines.
• Commitment to inclusive collaboration, ensuring diverse perspectives are considered in technical decisions and team dynamics.

Nice to have

• Experience with financial services technology or regulated environments, providing insight into compliance and risk considerations.
• Familiarity with AI-assisted development tools and frameworks that enhance engineering productivity and code quality.
• Background in open source contributions or community engagement, demonstrating a proactive approach to learning and collaboration.
• Exposure to performance optimization, debugging complex systems, and conducting post-incident reviews.
• Willingness to mentor junior engineers and support career development through coaching and constructive feedback.

Practical notes

• This is a full-time position based in the United Kingdom, London.
• The office environment offers flexible working hours to support focus and productivity.
• Weekly food pop-ups are available, along with a range of snacks and drinks provided on-site.
• Additional perks include a pension plan with up to 5 percent matching, life insurance at three times annual salary, and 25 days of holiday plus bank holidays.
• Parental leave includes six months fully paid maternity leave, four weeks fully paid paternity leave, and shared parental leave.
• We encourage applications from all backgrounds and abilities, including those with ADHD, autism, dyslexia, or dyspraxia.
• Benefits also encompass a cycle-to-work scheme, electric car scheme, season ticket loan, and two charity days per year.
• Applications will be reviewed on an ongoing basis until the role is filled.
• Relocation support may be available for candidates relocating to London, subject to business needs and eligibility criteria.