Senior Software Engineer - Backend

Company Description Who we are... At Trustonic, we make smartphones affordable for the many, enabling global access to devices and digital finance through the world’s most secure smartphone locking technology. We partner with mobile carriers, retailers, and financiers across 30+ countries, powering device financing solutions that drive economic inclusion, profitability, and growth. We pride ourselves on living by the Trustonic culture code, a blueprint for our journey that recognises that great working environments don’t guarantee success, but bad ones almost always ensure failure. Working here, you’ll find a company that celebrates its diversity and is looking to do the right thing: for each other, the community and the planet. We believe in equal opportunities and take to heart the old African proverb ’If you only want to go fast, go alone. If you want to go far, go together’. We work flexibly when and where we’re at our best, but regardless of how you choose to work, we’ll make sure you feel like one of the team. Click here if you would like to find out more about Trustonic's culture code. If you would like to work in a fast-moving global technology company, with great ambition, then we’d love to hear from you! Job Description A bit about the team and what you'll deliver... As a Senior Software Engineer - Backend you'll join a collaborative, highly skilled engineering team responsible for developing and operating Trustonic's cloud platform, which underpins secure services used by millions of connected devices worldwide. Working closely with Product, QA, DevOps and fellow engineers, you'll help shape the technical direction of our backend services while contributing to a culture of continuous improvement, knowledge sharing and engineering excellence. In this role, you'll deliver scalable, secure and resilient cloud-native solutions that enable the rapid development of new platform capabilities. Your work will directly influence the reliability, performance and scalability of our AWS-based services, helping to ensure our customers receive robust, high-quality solutions that meet the demands of a global, enterprise-scale platform. Please note, this is a hybrid role with regular attendance required at our office in Winnersh. As a Senior Software Engineer - Backend, you will: • Design, build, debug, and deliver cloud-native features across the Trustonic platform from early development through production release. • Develop and enhance AWS-based microservices, with strong focus on AWS Lambda, SQS-driven workflows, API Gateway, and AppSync integrations. • Build reliable backend services in Python 3 (FastAPI/Flask) and support event-driven processing patterns for high-scale device operations. • Collaborate with QA and product engineering teams to improve release quality, performance, and resilience of ALPS services. • Lead or participate in architecture discussions, design reviews, and code reviews across multiple backend services. • Implement and promote SDLC best practices: requirements refinement, test strategy, CI/CD, observability, and production support. • Diagnose and resolve production defects, performance bottlenecks, and integration issues across distributed systems. • Support L3 operations, incident response, and post-incident improvements for business-critical AWS workloads. Who you are... • Team player • Energetic and passionate about delivering great software in a rapidly growing environment • Prepared to invest whatever effort is required to get the job done • Operate with integrity and transparency and conduct business in a proper manner • Good creative intelligence • Tenacious with a problem-solving approach • Organised, rigorous and autonomous What makes you, you... Skills • Python 3.10+ - strong proficiency including type hints, dataclasses, and async patterns. • AWS Lambda Powertools (Logger, Tracer, Metrics) for observability. • FastAPI or Flask for containerised microservices. • Hands-on AWS expertise: Lambda, SQS, SNS, Step Functions, AppSync (GraphQL), API Gateway, CloudWatch, X-Ray, IAM, S3, and VPC fundamentals. • PostgreSQL RDS - schema design, Alembic migrations, query optimisation. • Redis - caching, pub/sub, distributed locks and idempotency patterns. • Serverless Framework v3, Docker (container-based Lambdas), Terraform, Jenkins CI/CD. • Apache Airflow DAG authoring and AWS Glue with PySpark for batch ETL. • pytest and moto (offline AWS service mocking), Black formatter, ruff linter. • Datadog APM tracing and structured JSON logging with Lambda Powertools. • Strong debugging skills across async event flows, API behaviour, and distributed systems. • Good working knowledge of Linux, Git workflows, and infrastructure as code. Experience and Knowledge • A degree in computer science, software engineering, or equivalent experience • Proven commercial experience building Python-based AWS Lambda services in production. • Strong experience with PostgreSQL (schema design, Alembic migrations) and DynamoDB (access patterns, Streams). • Experience with event-driven architectures: SQS, SNS, Step Functions, DLQ and retry patterns. • Hands-on AWS infrastructure experience: Serverless Framework v3, Terraform, ECR, IAM. • Experience deploying Docker container-based Lambda functions. • Data engineering background with Airflow DAGs and PySpark/Glue ETL pipelines is an advantage. • Multi-tenant SaaS platform experience at scale is desirable. • Familiarity with telecom, OEM device management, or IoT platforms is a plus. • Experience with CDC (Change Data Capture) and real-time data sync patterns is a plus. • Experience reading or maintaining Java Spring Boot services is beneficial. • AWS certification is highly desirable but not essential Qualifications Additional Information What we can provide you in return for your investment... Competitive compensation • A base salary that reflects your expertise and impact. • Bonus scheme to share in our success. Financial security & wellbeing • Immediate participation in our pension scheme. • Private medical insurance for you and your family from day one. • Income protection and life insurance for peace of mind. Flexibility & work-life balance • Hybrid working arrangements to support your lifestyle. • An open holiday policy with no upper limit—take the time you need, when you need it. • Support for volunteering and causes that matter to you. Growth & development • Opportunities for professional development and career progression. • Exposure and interaction with global teams. Inclusive, supportive culture • A commitment to diversity, equity, and inclusion. • A collaborative environment where your voice is valued and your wellbeing is prioritised. Impact & purpose • The chance to work on technology that drives global economic inclusion and makes a real difference in people’s lives. #LI-Hybrid Trustonic is an equal opportunity employer. We do not discriminate on any grounds. We empower, engage, enable and value differences between people, including; different races, ethnicities, genders, ages, religions, disabilities and sexual orientations, with differences in education, backgrounds, skill sets, experiences and knowledge.