Paper on CIEL, a distributed dataflow engine, at USENIX NSDI 2011. This work led by Derek G Murray introduced a universal execution engine that, unlike previous systems, enables data-dependent control-flow decisions for computing iterative and recursive algorithms. We also developed Skywriting, a Turing-complete scripting language that runs directly on CIEL with transparent fault tolerance and distribution. The system was deployed on cloud platforms and demonstrated scalable performance for both iterative and non-iterative algorithms, addressing a key limitation of earlier MapReduce-style systems.