David Silveiro
Orpington,Orpington
Summary
Senior Software Engineer with extensive experience building scalable, secure, and high-performance applications across web, cloud, and networking domains. Skilled in Python, Django, AWS, Docker, and modern front-end technologies, with a strong background in designing complex systems, mentoring teams, and improving operational efficiency. Comfortable bridging technical strategy with hands-on development, and always looking for smart, practical ways to solve challenging problems.
Overview
13
13
years of professional experience
Work history
Senior software engineer
Sky
London
12.2022 - Current
- Led end-to-end design, architecture, and delivery of a cutting-edge broadband network simulation platform — modelling large-scale UK-wide failures with NetworkX, Celery, GCP, FastAPI, React, Redis, MongoDB, and Python — optimising computational performance for heavy-scale graph analysis and directing cross-functional teams to deliver high-quality results on time.
- Delivered high-impact tooling that significantly improved operational decision-making and network resilience planning at a national scale.
- Designed and implemented algorithms controlling IP address allocation for the entire UK Sky network, ensuring efficient utilisation, compliance, and seamless scalability.
- Designed and implemented graph-powered solutions using Neo4j to model and query complex relational data at scale.
- Mentored junior engineers to senior-level proficiency, fostering a culture of technical excellence and peer-led growth.
- Engineered secure, high-performance APIs with Django, PostgreSQL, and Django REST Framework, ensuring compliance with security best practices and data protection requirements.
- Identified and remediated critical software vulnerabilities, safeguarding systems against potential exploitation and strengthening overall security posture.
Senior Software Engineer
JPMorgan
London
04.2022 - Current
- Developed and deployed scalable microservices using AWS Lambda and Python, optimising for performance, cost-efficiency, and maintainability.
- Managed and orchestrated containerised applications with Kubernetes, ensuring high availability and streamlined deployments.
- Designed and implemented new features in Django, aligning with business requirements and best practices.
- Refactored legacy functionality into modern, standards-compliant REST APIs, improving interoperability and maintainability.
- Provided hands-on guidance and mentoring to junior and mid-level developers, accelerating skill growth and improving team delivery.
- Enhanced front-end user experience with optimised CSS, JavaScript, and HTML5, improving usability and visual appeal.
Senior Software Developer
Accenture
London
07.2019 - 04.2022
- Maintained and enhanced a legacy Django application for Deutsche Bank, ensuring stability, performance, and compliance in a regulated environment.
- Served as Lead Developer for 2 years on a highly sensitive security application for Lloyds Banking Group, overseeing architecture, delivery, and security best practices.
- Migrated critical on-premise applications to AWS, improving scalability, resilience, and cost efficiency.
- Reviewed specifications and architected technology solutions in Django for 3 major projects, consistently meeting or exceeding performance and reliability targets.
- Transitioned CI/CD pipelines from GitLab to Bitbucket, streamlining workflows and improving build reliability.
- Introduced AWS CloudFormation into a penetration testing platform, enabling rapid, secure scaling in confidential and sensitive environments.
- Refactored and modernised legacy codebases, improving maintainability, reducing operational costs, and enhancing functionality.
- Containerised a legacy Django application with Docker, simplifying deployment and improving development workflows.
- Worked extensively with PostgreSQL and MySQL for robust, performant data storage and retrieval.
Automation Developer
AXA
Bournemouth
09.2018 - 08.2019
- Collaborated with developers, product owners, and junior testers to introduce structured testing procedures, significantly reducing post-deployment system outages.
- Developed large-scale C# integration tests spanning multiple applications, cutting pricing errors and data discrepancies.
- Contributed to cross-functional Agile projects, ensuring quality and delivery alignment across teams.
- Created automated REST API tests using IronPython, C#, and SoapUI, improving coverage and reliability.
- Developed API endpoints to precise specifications, ensuring performance and maintainability.
- Integrated SonarQube into the CI/CD pipeline, enabling continuous code quality monitoring.
- Introduced BDD practices via SpecFlow, making test scenarios more accessible to product owners and junior testers, and improving communication around requirements.
Software Developer in Test
Kognitiv
Bournemouth
09.2016 - 09.2018
- Developed automated test scripts to eliminate repetitive testing tasks, increasing efficiency and consistency in QA workflows.
- Provided actionable recommendations to developers, improving software performance, usability, and overall quality.
- Implemented Selenium automation across dozens of unique travel websites to detect front-end rendering issues with flight times, prices, and user flows — ensuring a seamless booking experience for travellers.
- Integrated Applitools AI-powered visual testing, detecting design deviations and front-end errors missed by traditional functional tests.
- Paired with junior developers on front-end tasks, providing mentorship and improving delivery quality.
- Discovered and exploited multiple RCE vulnerabilities, demonstrating risks using custom-built Visual Basic shells to drive remediation efforts.
Junior Python Developer
A2ZCloud
Salisbury
09.2015 - 02.2016
- Built VOIP systems for office administrative tasks using Twilio in Python, streamlining communication workflows.
- Developed backend features in Python with Twisted, enabling efficient, event-driven networking capabilities.
- Administered and hardened Linux hosts, improving security posture and operational reliability.
- Introduced Splunk to centralise and analyse logs across multiple hosts, enhancing visibility, troubleshooting speed, and incident response.
Junior Web Developer
Graftene
Bournemouth
01.2014 - 02.2015
- Applied JavaScript and Object-Oriented Programming principles to design effective, maintainable web solutions.
- Built responsive website interfaces using HTML and CSS, delivering user-friendly experiences.
- Developed intuitive page layouts and navigation tools, consistently meeting or exceeding user expectations.
- Integrated dynamic data retrieval from PHP and SQL databases via JavaScript, populating front-end elements in real time.
Junior Linux System Administrator
UK Local News
Bournemouth
01.2013 - 01.2014
- Interacted directly with users to diagnose and resolve critical system issues, ensuring smooth daily operations.
- Introduced and deployed Lubuntu on legacy on-premise systems, improving performance and extending hardware lifespan.
- Installed and partitioned Linux hosts, implementing secure configurations and optimising system resources.
- Implemented host-level security policies using IPTABLES and group management, strengthening system protection.
- Trained office users on Linux-based productivity tools, including open-source alternatives to Excel and Word, driving adoption and improving efficiency.
Education
Diploma of Higher Education - Electrical Engineering
Bournemouth And Poole College
06-2013
Skills
Programming & Development:
- Python (Django, Flask, Twisted, NetworkX)
- C
- JavaScript, HTML5, CSS3
- SQL (PostgreSQL, MySQL)
- NoSQL (MongoDB)
- Visual Basic (for scripting and security testing)
- Celery
- RabbitMQ
- Redis
Web & API Development:
- REST API design and development (Django REST Framework, FastAPI)
- Front-end development and UX enhancements
- API testing
- BDD/SpecFlow
- Cypress
- Selenium
Cloud & DevOps:
- AWS (Lambda, CloudFormation, general cloud migrations)
- Docker containerisation
- CI/CD pipelines (GitLab, Bitbucket, Jenkins)
- Redis
- Splunk (log aggregation and monitoring)
- Celery (task queues and background processing)
- Terraform
- Ansible
- Security (OWASP)
Testing & Quality Assurance:
- Automated testing frameworks (Pytest, Selenium, Applitools)
- Large-scale integration and regression testing
- SonarQube for code quality
- Security testing and vulnerability identification (RCE, penetration testing)
Networking & Systems:
- IP allocation algorithms and network resilience modelling
- Linux administration and hardening (Lubuntu, security policies, IPTABLES)
- VOIP systems (Twilio)
- System performance optimisation and troubleshooting
Collaboration & Leadership:
- Mentoring and training junior/mid-level developers
- Agile/Scrum methodologies
- Cross-functional team collaboration (developers, testers, product owners)
- Technical leadership and project architecture
Other Tools & Technologies:
- Neo4j (graph databases)
- Twilio, event-driven programming (Twisted)
- Cloud and local deployment orchestration
Accomplishments
- Discovered and responsibly disclosed multiple zero-day vulnerabilities in widely-used Linux utilities and web applications, contributing to improved security across the open-source and enterprise communities
Timeline
Senior software engineer
Sky
12.2022 - Current
Senior Software Engineer
JPMorgan
04.2022 - Current
Senior Software Developer
Accenture
07.2019 - 04.2022
Automation Developer
AXA
09.2018 - 08.2019
Software Developer in Test
Kognitiv
09.2016 - 09.2018
Junior Python Developer
A2ZCloud
09.2015 - 02.2016
Junior Web Developer
Graftene
01.2014 - 02.2015
Junior Linux System Administrator
UK Local News
01.2013 - 01.2014
Diploma of Higher Education - Electrical Engineering
Bournemouth And Poole College
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