Senior Software Engineer

The Role
We are seeking a talented Senior Software Engineer to help build and run the data services and platform behind Datalex's dynamic pricing and offer optimisation. This is a Python-first, backend and infrastructure-focused role: you will work on end-to-end solutions — from robust application code and data pipelines through to APIs, infrastructure-as-code, and production monitoring.
You will design and maintain the services that turn large volumes of pricing and offer data into fast, reliable, production-grade functionality, and you will help integrate machine learning and optimisation models into that pipeline. The role blends software engineering excellence, strong AWS and data-engineering skills, and a pragmatic eye for automation.
Experience in the travel, airline retailing, or e-commerce industry would be a distinct advantage.

Responsibilities

• Design, implement, and maintain Python services within our pricing platform, including data-processing logic and the integration of ML/optimisation models. Write clean, efficient, well-tested code for backend logic and data services.
• Build and optimise data pipelines on AWS to collect, transform, and serve large datasets. Work extensively with S3 (Hive-partitioned Parquet data lake), Athena for SQL querying and analysis, DynamoDB for low-latency caching, and Kinesis/SQS for streaming and queue-based integration — including customer-facing "bring your own stream" pipelines.
• Develop robust RESTful APIs and services (FastAPI) that expose pricing and data functionality. Ensure they are secure, well-documented, and performant at scale.
• Write and maintain comprehensive tests using PyTest. Ensure new features have proper coverage and meet quality standards before deployment.
• Own infrastructure as code using Terraform. Containerise applications with Docker and work across our CI/CD tooling — Bitbucket Pipelines and Jenkins — to automate build, test, and deployment.
• Deploy services into production and keep them healthy. Build observability with Datadog and CloudWatch, investigate data-quality issues (typically via Athena), and diagnose infrastructure problems using CloudTrail/CloudWatch.
• Work closely with data scientists to productionise pricing and optimisation models, and implement monitoring to track model performance, accuracy, and reliability post-deployment.
• Contribute to architectural decisions — for example, weighing in-process logic against extracted microservices — and proactively suggest improvements to systems and processes.
• Provide technical guidance and mentorship to junior engineers.

• Bachelor's degree in Computer Science, Engineering, or a related field (or equivalent work experience).
• At least 8 years' experience as a Software Engineer on large, production software applications.
• Strong Python engineering skills, including dependency and environment management with Poetry.
• Hands-on experience with AWS, particularly S3, Athena, DynamoDB, Kinesis, SQS, ECS, and CloudWatch.
• Experience building RESTful APIs and services with FastAPI.
• Hands-on experience with Infrastructure as code with Terraform.
• Containerisation with Docker.
• Data-engineering fundamentals: working with Parquet, Hive-partitioned datasets, and SQL against large tables (Athena/Presto). Solid working knowledge of the PyData stack — pandas and NumPy for data manipulation, Jupyter for experimentation, matplotlib/Seaborn for visualisation — and experience troubleshooting data-quality issues.
• Testing discipline with PyTest and a commitment to meaningful coverage.
• Experience with observability tooling (Datadog).
• Knowledge of design patterns and software architecture.
• Strong problem-solving and analytical skills.
• Good presentation and teamwork skills.
• Comfortable working in both Agile and Waterfall methodologies.

• Familiarity with ML/optimisation frameworks used to productionise pricing models.
• Git for version control, with Bitbucket for collaboration, and experience configuring CI/CD pipelines (Bitbucket Pipelines and/or Jenkins).
• Exposure to AWS security and networking services (e.g. WAF), and to cross-account S3 replication.
• Experience in travel, airline retailing, or e-commerce.

About Datalex 
 
Datalex is a market leader in airline e-commerce solutions. Datalex's Stellex product suite, launched in 2024, gives airlines the tools they need to drive revenue and profit as digital retailers. Datalex has a strong track record working with some of the most innovative airline brands worldwide, such as Air China, Air Macau, Air Transat, Aer Lingus, easyJet, and Edelweiss. The Group is headquartered in Dublin, Ireland, and maintains offices across Europe, the Americas, and Asia. Learn more at www.datalex.com