Flow reactions are described as the flow of reagents and products in and out of the reaction vessel continuously. The flow platform consists of a fluid delivery system, mixing tools, reactors, quenching units, pressure regulation units, and collection vessels. The fluid delivery is normally executed using either HPLC, syringe or peristatic pumps. A passive mixing stage where the reagents are introduced to the system through a Y or T connection is the most common approach observed for most flow reactions, more specialized mixing tools can be incorporated depending on the reaction requisites. The most common reactors used are either microfluidic chip or coil-based reactors for solution chemistry. Packed bed reactors are used when solid heterogenous catalysts are handled. Specialized reactors for electro and photochemical experiments have also been developed. Depending on the flow of the reaction mixture, flow reactions can be continuous or segmented (also known as slug). Segmented flow reactions present an efficient means to gather diverse data points by creating segmented or droplet flow within microfluidic reactors. Each droplet is carefully separated by either an antisolvent or an inert gas, thus providing every droplet with the functionality of an individual reactor. This segmentation ensures precise control over reactions and prevents interference between different reaction environments. Moreover, the ratios of reagents within these droplets are easily modulated using syringe pumps, providing users with a convenient means to collect data efficiently and coherently. This approach streamlines experimentation processes, enhances reproducibility, and facilitates the exploration of complex reaction spaces with unprecedented accuracy. Droplet microfluidics has emerged as a powerful tool across diverse scientific disciplines, with dedicated literature offering concepts behind the droplet formation . An example of a segmented flow droplet system was employed to screen a range of organic solvents for achieving optimal mono-alkylation of trans-1,2-diamino cyclohexane . The HTE methodology in combination with feedback DoE facilitated the rapid identification of prime solvents, notably DMSO, DMF, and pyridine, leading to enhanced yields of the mono-alkylated product. An experimental setup was developed for single-droplet studies of visible-light photo redox catalysis in this case using an oscillatory flow strategy . In an oscillatory reactor an alternating pressure gradient is applied within the reactor causing a back-and-forth oscillation of the reaction slugs, which leads to higher control in mixing and extended residence time of the reaction mixture. About 150 reaction conditions were explored using a total volume of 4.5 mL reaction mixture and the screening results are readily translated to continuous flow synthesis. The application of segmented flow or micro-slug reactor was demonstrated in the decarboxylative arylation cross-coupling reaction promoted by catalysts and light . The design allows the screening to be more material and time-efficient in the optimization of both continuous variables (e.g., temperature and residence time) and discrete variables (e.g., catalyst. base). Pieber et al. reported the application of a segmental flow reactor for heterogenous solid-liquid reactions. In their report, they described the reaction slugs as serial micro-batch reactors (SMBRs) separated through gas segments that incorporated liquid reagents and solid photocatalysts in a continuous flow. The slugs were generated by establishing a stable gas-liquid segmented-flow pattern using a Y-shaped mixer, followed by the suspension of the catalyst via a T-mixer. This technology was utilized to develop selective and efficient decarboxylative fluorination reactions. Recently, a slug flow platform was developed (Figure ) by injecting segments of gas as a separating medium for enhancing the optimization of the Buchwald-Hartwig amination intermediate, which is crucial for synthesizing the drug olanzapine . The reactor setup was integrated with spectroscopic and chromatographic in-line analytical tools, enabling the real-time monitoring of products and reaction intermediates. A detailed discussion on the optimization strategy is described in section 4 (Table , entry 19). Robochem a HTE platform was designed to streamline the screening of photochemical reactions, facilitating the rapid generation of diverse reaction mixtures each comprising 650 uL within a slug flow reactor . This innovative system features precise monitoring of the reaction slug through a dedicated array of phase sensors and an algorithm designed for detecting its passage. As a result, the workflow delivers a notable boost in productivity, surpassing traditional batch reactions by over 500-fold and outperforming flow reactions with a five-fold improvement. A fully integrated automated multistep chemical synthesizer (AutoSyn) was reported to autonomously synthesis milligram-to-gram-scale amounts of any organic molecules or drug-like molecules . The system comprised a flow chemistry synthesis platform, a reagent delivery system, a packed bed reactor, and process analytical tools. An integrated software control system that automates end-to-end process operations and monitoring. The system has been used to demonstrate the synthesis of at least 10 drug molecules autonomously and there is no closed-loop optimization framework is embedded.