Leo Wheelan

Email: [email protected] | LinkedIn: https://www.linkedin.com/in/lwheelan

Professional Summary

Software Developer with 8+ years of experience building scalable and user-focused software solutions, primarily in startup and scale-up environments. Expertise in distributed systems, event-driven architecture, and observability. Passionate about designing impactful software products and mentoring teams for technical and professional growth.

Professional Experience

Senior Software Engineer

Onfido (June 2024 – Present)
Onfido provides identity verification services across industries.

• Cost Optimization: Partnered with multiple teams to devise and implement cost-reduction strategies for service operations.
• Data-Driven Decision-Making: Designed and conducted A/B tests to validate new user experience hypotheses.
• Feature Deployment: Increased roll-out of critical features while ensuring stable clearance rates.

Staff Software Engineer

Birdie (April 2019 – June 2024)
Birdie delivers digital solutions to enhance care quality for homecare agencies.

• Payroll/Invoicing Platform: Designed and developed an event-sourced invoicing and payroll system using F#, NodeJS, EventStoreDB, PostgreSQL, Kafka, and React.
• Database Reliability: Led a PostgreSQL migration initiative, improving service reliability through isolated database instances.
• Observability Leadership: Built dashboards with Grafana, Prometheus, DataDog, and Honeycomb to monitor SLOs/SLAs. Established observability best practices and coached engineers on deployment strategies and alarm tuning.
• Team Enablement: Implemented CI/CD pipelines to enable teams to deploy rapidly with confidence to production.
• Mentorship: Guided junior engineers in career progression through actionable goals and personalized development plans.
• Knowledge Sharing: Conducted workshops on technical and architectural topics to upskill team members.

Software Engineer

Heed Software (January 2017 – March 2019)
Heed delivers a real-time communication platform tailored for actionable notifications.

• Real-Time Systems: Built a real-time messaging application leveraging NodeJS, RabbitMQ, MongoDB, and WebSockets.
• Workflow Automation: Developed a workflow product to automate custom responses for system events.
• GraphQL Implementation: Designed and deployed a GraphQL API to improve efficiency and minimize overfetching.
• Desktop Application: Created a premium client-side Electron app extending SaaS functionality for enterprise clients.
• Mobile Alerts: Built a mobile application for time-sensitive user notifications.

Education

MPhys (Hons), The University of Manchester

Upper Second Class Honours (68.5%)

A-Levels, Petroc College, North Devon

• Mathematics: A*
• Physics: A
• Chemistry: B

Technical Skills

• Programming Languages: NodeJS + TypeScript, Go, F#, Python
• Technologies: PostgreSQL, Kafka, MongoDB, EventStoreDB, RabbitMQ, React, Electron
• Observability Tools: Grafana, Kibana, Prometheus, DataDog, Honeycomb
• Methodologies: Event-Driven Architecture, Microservices, CI/CD, Agile, TDD
• DevOps: Docker, Kubernetes

Additional Achievements

• Spearheaded cost-saving initiatives, reducing service operating expenses significantly.
• Improved organizational reliability metrics through robust database and observability solutions.
• Recognized as a key mentor and coach for junior engineers across multiple teams.