Katara: synthesizing CRDTs with verified lifting

Conflict-free replicated data types (CRDTs) are a promising tool for designing scalable, coordination-free distributed systems. However, constructing correct CRDTs is difficult, posing challenge even seasoned developers. As result, CRDT development still largely the domain of academics, with new designs often awaiting peer review and manual proof correctness. In this paper, we present Katara, program synthesis-based system that takes sequential type implementations automatically synthesizes verified from them. Key to process formal definition correctness combines reference lightweight ordering constraint resolves conflicts between non-commutative operations. Our follows tradition work in lifting, including an encoding into SMT logic using synthesized inductive invariants hand-crafted grammars state runtime. Katara able synthesize wide variety scenarios, reproducing classic synthesizing novel based on specifications existing literature. Crucially, our fully, verified, eliminating entire classes common errors reducing producing painstaking paper specification.