Continuous Delivery: Solving the Talent Problem - Walmart

Summary

Brent Pendergraft and Brian Finster, from a small retailer in Northwest Arkansas, discuss their journey to solve the talent problem and achieve continuous delivery. They highlight the transformation of their development culture, moving from a legacy system to microservices and Kubernetes, which drastically reduced deployment times. The talk emphasizes overcoming technical debt, fostering a learning culture, and the importance of quality and testing. They also share insights on retaining talent by providing a development environment that encourages growth and innovation.

Takeaways

• 🛒 Walmart's Scale: The company serves 250 million customers weekly and operates 11,000 stores across 28 countries, highlighting the need for a robust supply chain.
• 🚀 Distribution System Challenge: The challenge of deploying updates to 300 distribution centers with minimal outages, which was initially a daunting task due to legacy systems.
• 🔧 Modernization Efforts: A transition from legacy systems to a modern environment with microservices, on-demand deployments, and piloting Kubernetes clusters to streamline the supply chain.
• 🔄 Continuous Integration as a Lever: The use of continuous integration as a tool for change, emphasizing the importance of integrating with master branches daily to improve deployment speed.
• 🛠️ Technical Debt and Instability: The struggle with aged systems and technical debt that led to instability, necessitating a focus on quality and a single automated path to production.
• 📊 Metrics for Stability: The adoption of test coverage as a metric for product stability and quality, and the realization that a holistic approach to quality measurement is necessary.
• 💡 Test-Driven Culture: The importance of fostering a test-driven culture where testing is a daily habit and an integral part of the development process.
• 🌟 Domain-Driven Design: The shift towards domain-driven design to decompose the monolith and create logical separation of business concerns, enhancing maintainability.
• 🤝 Cross-Team Collaboration: The benefits of breaking down organizational silos and encouraging collaboration across different teams to expedite the development process.
• 🌱 Learning and Growth: The transformation of the development culture that promotes learning, growth, and a love for development, making the work environment more attractive.
• 🔑 Empowering Developers: The empowerment of developers with the freedom to improve and innovate, leading to a more engaged and productive team.

Q & A

What is the challenge that Brent and Brian were given by management in 2014 regarding the distribution systems?

Brent and Brian were challenged to deploy their distribution systems every two weeks with no outages. This was a significant task considering the legacy systems they were working with at the time.

How many distribution centers does Walmart support, and what is the volume of cases handled per hour?

Walmart supports nearly 300 distribution centers with a volume of 3 million cases per hour.

What is the annual banana volume handled by Walmart's distribution system, and how does it compare to the weight of blue whales?

Walmart handles about a billion pounds of bananas annually, which is equivalent to the weight of 11.2 blue whales per day.

What changes did the team implement to move from a legacy system to a more modern, agile deployment system?

The team transitioned to building microservices, piloting Kubernetes clusters, and enabling on-demand deployments with no outages for application changes, significantly reducing deployment times from weeks or months to hours.

What were the main pain points discussed by Brent and Brian that they had to overcome during their transformation?

The main pain points included extended cycle times, organizational silos, and the challenge of moving quickly in a volatile retail space.

How did the team address the issue of organizational silos and the impact on speed?

They leveraged relationships built over time to bypass organizational friction, created enterprise deployment tooling for all teams, modernized their tech stack, and set a defined goal for continuous integration.

What role did continuous integration play in the transformation process, and how did they implement it?

Continuous integration served as a lever for change. They defined it, held themselves accountable to it, and used it to break down larger problems into smaller, more manageable ones.

What was the team's approach to dealing with technical debt and the need for quality improvements?

They created a single automated path to production, established metrics for stability and quality (like test coverage), and emphasized the importance of a testing culture.

How did the team ensure that their architecture was flexible and could adapt to changing business needs?

They adopted domain-driven design to isolate business capabilities, tied these to teams, and ensured that the architecture could be split at any point, allowing for microservices to be handed out to smaller teams as needed.

What impact did the transformation have on the team's culture and the way they approached development?

The transformation led to a more engaging and enjoyable development culture, with a focus on learning, problem-solving, and close collaboration with users, ultimately making the area more attractive for talent internally and externally.

How did the team ensure that their development practices were sustainable and not just a temporary change?

They emphasized the importance of a testing culture, continuous learning, and the use of metrics to measure quality and stability, ensuring that these practices were integrated into their daily work.