Kristoffer focused on backend development for the flashbots/op-rbuilder and flashbots/rollup-boost repositories, delivering four features centered on stability and developer productivity. He upgraded Reth dependencies across both codebases, aligning them with the latest Rust ecosystem standards and improving compatibility with core crates. Kristoffer simplified test setups in op-rbuilder by removing redundant account initialization, which reduced CI noise and accelerated feedback cycles. He also refactored internal naming in OpPayloadBuilderCtx to clarify code intent, enhancing maintainability. His work demonstrated strong skills in Rust, dependency management, and code clarity, laying a foundation for smoother future integrations and more efficient development workflows.