Senior Platform & Data Engineer - Scale & Impact (Hybrid)

twentyAI; Greater London; Hybrid; GBP 70,000 - 110,000; Full time

Job summary

twentyAI is seeking a Senior Engineer to join its established financial markets technology team. You will design, build and enhance backend services and data platforms operating at scale, with a focus on reliability and automation.

The role spans software, data and distributed systems, and involves mentoring teammates. You will work in a hybrid environment, translating business requirements into robust engineering solutions and contributing to architecture, testing, and production reliability

Qualifications

• 5+ years of commercial software engineering experience.
• Strong backend development experience in a Java + Spring environment.
• Experience working with Python and/or the Microsoft technology ecosystem.
• Strong understanding of distributed systems and scalable application design.
• Strong experience with Apache Spark or PySpark.
• Experience designing modular applications, services or microservice-based architectures.
• Strong knowledge of software engineering principles, design patterns and clean code practices.
• Experience with automated testing across unit, integration and end-to-end environments.
• Good understanding of CI/CD, automated deployment and modern software delivery practices.
• Experience with event-driven architectures, messaging or streaming technologies such as Kafka.
• Exposure to high-volume data processing or distributed data platforms.
• Strong SQL and relational database experience.
• Experience supporting highly available, business-critical production systems.
• Comfortable investigating performance, reliability and production issues.
• Able to work independently while collaborating across technical and non-technical teams.
• Experience mentoring or providing technical guidance to other engineers.
• A degree in computer science, engineering or a related discipline is advantageous.

Responsibilities

• Design and develop backend applications, services and data-driven platforms.
• Build and enhance distributed systems handling high volumes of data.
• Assess technical approaches and contribute to architecture and design decisions.
• Translate business and technical requirements into robust engineering solutions.
• Produce clear technical designs and documentation.
• Develop automated testing across different stages of the software lifecycle.
• Contribute to CI/CD, release automation and improvements to engineering practices.
• Work closely with engineering, product, architecture and operational teams.
• Investigate and resolve complex issues affecting production systems.
• Support and mentor other engineers within the team.
• Help improve the performance, resilience and maintainability of existing platforms.

Skills

Backend development

Java + Spring

Python

Distributed systems

Spark (Spark/PySpark)

Microservices

CI/CD

Kafka

SQL / Relational DB

Production systems

Mentoring

Education

Degree in computer science, engineering or related

Job description

twentyAI is seeking a Senior Engineer to join its established financial markets technology team. You will design, build and enhance backend services and data platforms operating at scale, with a focus on reliability and automation.

The role spans software, data and distributed systems, and involves mentoring teammates. You will work in a hybrid environment, translating business requirements into robust engineering solutions and contributing to architecture, testing, and production reliability