Atomically thin transition metal dichalcogenides (TMDs) have attracted recent interest due to their unique excitonic properties. Lateral confinement of excitons to generate two-dimensional exciton arrays may open up new avenues for quantum optoelectronics such as topological photonics and quantum emitter arrays. Realizing such emitter arrays, however, requires the development of new methods to engineer the excitonic energy landscape at the nanoscale. In this talk, I will focus on how to use twisted TMD bilayers to engineer the coherence and relaxation properties of excitons. I will discuss lattice reconstruction effects in the moiré pattern and correlating their importance in determining the excitonic behaviors. Finally I will discuss prospects of realizing tunable exciton arrays in twisted heterostructures for exploring novel optoelectronics and many-body states.