I am working with asterisk more then 18 years.
Have at least 15 years of extensive DEVELOPMENT work.
My primary services are VoIP systems design, billing for VOIP, web for VoIP/reporting interfaces.
I have compleated some autodiallers, including one with 20k concurrent calls, proved I can do complex modules for freepbx/trixbox, have done some a2billing contributions.
Also I have experience with multi-server VoIP clusters end virtualized VoIP services, including ones in amazon ec2.
-small and large VOIP system based on SIP protocol
-general VoIP architecture design
-web and billing for VoIP
-support for asterisk, FreePBX/trixbox and a2billing, openser/kamailio/opensips.
-modules and addons for asterisk, freepbx, a2billing
-load-balance using openser/kamailio/opensips
-virtualization with openvz, xen, amazon ec2 service.
-support for linux systems and supply services for voip.
-create network storage clusters, mysql replicated setup, mysql-clustered experience
-per hour support and consulting for all above
every finished project have free limited 10 day support&bugfixes.
note, I have near zero aborted projects, most of them from client-side. I have NO "work-in-progress-forever" list like a lot of users have. so the completion rate is REAL.
The only thing I not do is graphical design work, I'm sorry, but it is hard to be professional in VoIP and design in the same time. I have choosed to be best in VOIP