This paper describes the development of a fast, robust, and tunable synthetic gene oscillator in *Escherichia coli*. The oscillator is designed using a previously modeled network architecture with linked positive and negative feedback loops, which allows for precise control of oscillatory periods as short as 13 minutes. The design principles, including the importance of time delays in the negative feedback loop, are discussed. The robustness and persistence of oscillations are demonstrated through experiments using a microfluidic platform, where individual cells exhibit large-amplitude fluorescence oscillations. The oscillatory period can be tuned by altering inducer levels, temperature, and media source. Computational modeling reveals that the key to robustness lies in the time delay in the negative feedback loop, which can arise from cellular processes involved in forming functional transcription factors. The positive feedback loop enhances robustness and tunability. The authors also construct a simplified oscillator without positive feedback, confirming the computational predictions. The findings highlight the importance of considering intermediate steps in gene circuit design to achieve robust and tunable oscillations.This paper describes the development of a fast, robust, and tunable synthetic gene oscillator in *Escherichia coli*. The oscillator is designed using a previously modeled network architecture with linked positive and negative feedback loops, which allows for precise control of oscillatory periods as short as 13 minutes. The design principles, including the importance of time delays in the negative feedback loop, are discussed. The robustness and persistence of oscillations are demonstrated through experiments using a microfluidic platform, where individual cells exhibit large-amplitude fluorescence oscillations. The oscillatory period can be tuned by altering inducer levels, temperature, and media source. Computational modeling reveals that the key to robustness lies in the time delay in the negative feedback loop, which can arise from cellular processes involved in forming functional transcription factors. The positive feedback loop enhances robustness and tunability. The authors also construct a simplified oscillator without positive feedback, confirming the computational predictions. The findings highlight the importance of considering intermediate steps in gene circuit design to achieve robust and tunable oscillations.