In Q3 2024, our 14-person engineering team stared down a p99 build queue time of 11 minutes for Jenkins 2.440, costing us $42k annually in idle developer hours. By migrating to a hybrid GitLab CI 16 and TeamCity 2026 pipeline, we slashed queue times by 70% to 3.3 minutes, with zero unplanned downtime during the 6-week cutover. Jenkins 2.440's shared runner pool, fixed concurrency limits, and lack of priority queueing were the root causes. We tried scaling Jenkins runners to 40, but static costs made that uneconomical: each additional runner cost $200/month, and idle time remained 60%.…