Shift Left: Lessons Learned from 30 Years of Building With Dave North, Principal Engineer at Rewind How do you make cost part of engineering without slowing engineers down? Mike Weider talks with Dave North about how Rewind brings cost visibility and ownership into the software development lifecycle. Dave shares practical lessons on modeling costs before building, spotting inefficiencies in production, and getting engineers engaged through visibility and cost champions. They also explore how AI is changing the process, from building interactive cost simulators to automating code reviews, and why small changes to prompts, logs, and database records can have a meaningful impact at scale. About the guest Dave North is a Principal Engineer at Rewind, a SaaS backup company serving more than 25,000 companies worldwide. He brings over 30 years of engineering experience across large corporations and startups. At Rewind, he has built and led CloudOps, platform, security, and IT teams. Today, he focuses on complex problems that span engineering and the wider business. Key takeaways “You build it, you run it, you cost it.” Engineering teams own the cost of their applications, while the platform team supports infrastructure optimization.Model costs before writing code. Early estimates should establish the scale of expected spend, not predict every penny.Close the loop in production. Monthly cost reviews, tagging, and budget alerts help teams compare expectations with actual usage and investigate anomalies.Make costs visible and relevant. Dave describes a previous initiative where team-level reports and a leaderboard helped reduce development-environment costs by roughly 75%.Focus on material opportunities. Cost champions and clear priorities help engineers address meaningful waste without getting distracted by tiny savings.Use AI to explore tradeoffs. Rewind uses AI-built simulators to test worker counts, autoscaling settings, load, and cost before implementation.Optimize AI usage too. Dave reports reducing token usage by approximately 80% in one application through prompt changes that enabled caching.Keep humans involved where risk is high. Rewind’s AI review tool, Diff Vader, handles many pull requests, while sensitive security and backup-path changes still require human review.Small changes add up at scale. Shorter log messages reportedly reduced logging costs by about 20%. Smaller database records can also reduce consumption. Chapters 00:00 Introducing Dave North01:11 Dave’s role and Rewind’s major cost drivers02:47 What shifting left means in practice05:37 Cost ownership and modeling across the SDLC07:42 Catching waste with alerts and monthly reviews09:20 Breaking down costs by service, platform, and customer11:33 Engaging engineers through visibility and cost champions13:40 Balancing cost optimization with shipping speed15:29 AI-powered cost analysis and interactive simulators17:24 Managing AI spend and improving prompt caching19:16 Diff Vader: AI code reviews with human guardrails23:05 Practical savings from logs and database records Links RewindFrugal AIWatch on YouTubeListen on SpotifyListen on Apple Podcasts
