Choreographic programming (CP) is a method to implement distributed systems that ensures communication deadlock freedom by design. To use CP, though, the number of processes and the network among them must be known statically. Often, that information is known only dynamically. Thus, existing CP languages cannot be used to implement process-parametric distributed systems. This paper introduces first-person choreographic programming (1CP) to support the implementation of process-parametric distributed systems while also ensuring communication deadlock freedom. We present both a design of 1CP (new calculus, formalised in Isabelle/HOL) and an implementation (new language and tooling, integrated in VS Code).