Deepseek V4's 1M context window: the breaking point

Just ran to verify deepseek v4's context claim of 1M and ran it across three production codebases like 45k (microservice), 180k (monorepo backend) and 520k(full stack app). For the observation, tasks included dependency tracing, cross file refractors and bug isolation to see where recall keeps up under 150k Got a solid performance like at 45k tokens, function calls traced across 8 files maintain accurate path reconstruction.