Senior Developer

Cognizant; Greater London; Hybrid; GBP 90,000 - 120,000; Full time

Job summary

Cognizant in London is seeking a Lead Developer to design, implement and optimize Python and cloud-based solutions using AWS and PySpark for data-intensive, regulatory-focused applications. Hybrid day shift model in Stratford London (3 days a week).

You will own end-to-end technical delivery, ensure code quality and performance, and guide the team on secure coding and scalable architectures. The role emphasizes collaboration with stakeholders and delivering compliant data workflows.

Qualifications

• Experience designing and delivering Python-based solutions for data-intensive and regulatory-focused applications.
• Strong knowledge of AWS services and cloud architectures.
• Proven ability to optimize performance and ensure code quality in delivery pipelines.

Responsibilities

• Design scalable Python applications for complex data sets and regulatory requirements.
• Develop secure, efficient AWS-based data processing pipelines.
• Create and optimize PySpark jobs for large-scale transformations.
• Write robust PL/SQL procedures and queries supporting data integrity and reporting.
• Collaborate with product owners to translate governance needs into technical deliverables.
• Review code and drive secure coding practices across Python services and AWS configurations.

Skills

Python

AWS

PySpark

PL SQL

Job description

Role: Lead Developer

Location: Stratford London (3 days a week)

Employment: Fulltime

Purpose of the role:

Lead Developer role for a global organization, responsible for designing, implementing and optimizing Python and cloud based solutions using AWS and PySpark for data intensive and regulatory focused applications. The role requires strong experience in PL SQL and AWS services, owning end to end technical delivery, code quality and performance in a hybrid day shift model with no travel.

Responsibilities:

• Design scalable Python applications that process complex business and regulatory data sets, ensuring robustness, maintainability and clear modular structure for long term reuse and evolution.
• Develop secure and efficient solutions on AWS cloud that leverage core services to support highly available data processing pipelines and transaction workflows aligned with enterprise standards.
• Implement optimized PySpark jobs for large scale data transformations, ensuring efficient resource usage, predictable performance and alignment with agreed data models and quality rules.
• Create and refine PL SQL procedures and queries that support data integrity, regulatory reporting demands and high volume operations while maintaining consistent performance across environments.
• Coordinate with product owners and business stakeholders to translate regulatory and governance needs into clear technical requirements and deliverables that directly support compliance objectives.
• Review and refine code contributions from the development team, ensuring adherence to Python coding standards, AWS best practices and database optimization guidelines for consistent quality.
• Provide detailed technical estimates and task breakdowns for Python, AWS and data engineering work, enabling accurate planning of sprints and transparent communication of delivery timelines.
• Guide the adoption of secure coding patterns, encryption and access control mechanisms across Python services and AWS configurations to protect sensitive data in regulatory contexts.
• Collaborate with cloud operations and security teams to validate deployment configurations, monitoring coverage and incident response procedures for critical applications running on AWS.
• Analyze production issues related to Python services, data pipelines or PL SQL routines, identifying root causes and implementing durable fixes that minimize repeat incidents and downtime.
• Document solution architectures, service interactions and data flows in clear technical design records that support audit needs and knowledge transfer for governance and compliance programs.
• Drive continuous improvement in build and deployment automation using Python tooling and AWS native capabilities to reduce manual effort, accelerate releases and improve reliability of changes.
• Align daily development activities with the organization purpose by building trustworthy systems that help clients meet regulatory obligations and contribute to more transparent and compliant markets.

Certifications Required

• Preferred certifications include AWS Certified Developer Associate or AWS Certified Solutions Architect Associate and a Python programming certification.