Looking for magento 2 - performance turning (Non functional expert) -- 2

Calling magento 2 expert to tune my magento 2 site to be load less than 300ms for both front end and back end. Total sku about 9000. I only have a basic vps. centos linux. > spec as below Memory: total used free shared buff/cache available Mem: 4194304 2772056 697768 131048 724480 1291184 Swap: 524288 524288 0 Disk: Filesystem Size Used Avail Use% Mounted on /dev/ploop23232p1 449G 25G 406G 6% / none 2.0G 0 2.0G 0% /sys/fs/cgroup none 2.0G 0 2.0G 0% /dev tmpfs 2.0G 0 2.0G 0% /dev/shm tmpfs 2.0G 116K 2.0G 1% /run tmpfs 410M 0 410M 0% /run/user/0 =================================== CPU Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian CPU(s): 4 On-line CPU(s) list: 0-3 Thread(s) per core: 1 Core(s) per socket: 4 Socket(s): 1 Vendor ID: GenuineIntel CPU family: 6 Model: 79 Model name: Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz Stepping: 1 CPU MHz: 2353.271 BogoMIPS: 4200.35 Virtualization: VT-x Hypervisor vendor: Parallels Virtualization type: container L1d cache: 32K L1i cache: 32K L2 cache: 256K L3 cache: 20480K Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu cpuid_faulting pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid dca sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowprefetch epb cat_l3 cdp_l3 invpcid_single intel_ppin intel_pt ssbd ibrs ibpb stibp tpr_shadow vnmi flexpriority ept vpid fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 erms invpcid rtm cqm rdt_a rdseed adx smap xsaveopt cqm_llc cqm_occup_llc cqm_mbm_total cqm_mbm_local dtherm ida arat pln pts md_clear spec_ctrl intel_stibp flush_l1d