Below are some papers from LocalSolver team members that detail local search approaches for diverse combinatorial optimization problems, with some focus on low-level implementation details:
T. Benoist, B. Estellon, F. Gardi, A. Jeanjean (2011). Randomized local search for real-life inventory routing. Transportation Science 45(3), pp. 381-398. pdf (extended version pdf)
F. Gardi, K. Nouioua (2011). Local search for mixed-integer nonlinear optimization: a methodology and an application. In Proceedings of EvoCOP 2011, the 11th European Conference on Evolutionary Computation in Combinatorial Optimisation (P. Merz, J.-K. Hao, eds.), Lecture Notes in Computer Science 6622, pp. 167-178. Springer, Berlin, Germany. pdf
B. Estellon, F. Gardi, K. Nouioua (2009). High-performance local search for task scheduling with human resource allocation. In Proceedings of SLS 2009, the 2nd International Workshop on Engineering Stochastic Local Search Algorithms (T. Stützle, M. Birattari, H.H. Hoos, eds.), Lecture Notes in Computer Science 5752, pp. 1-15. Springer, Berlin, Germany. pdf pdf
B. Estellon, F. Gardi, K. Nouioua (2008). Two local search approaches for solving real-life car sequencing problems. In Special Issue: The Car Sequencing Problem (C. Solnon, V.D. Cung, A. Nguyen, C. Artigues, eds.), European Journal of Operational Research 191(3), pp. 928-944. pdf
B. Estellon, F. Gardi, K. Nouioua (2006). Large neighborhood improvements for solving car sequencing problems. In Special Issue: Journées Francophones de Programmation par Contraintes 2005 (F. Fages, N. Jussien, C. Solnon, eds.), RAIRO Operations Research 40(4), pp. 355-379. pdf
These research works have inspired the development of LocalSolver.