Mellum2 is an open-source 12B model released under Apache 2.0 and designed from scratch for software engineering workflows. JetBrains says it is especially suited for routing, summarization, Q&A, intermediate reasoning, and fast sub-agents.
The model is meant to solve latency, throughput, and cost problems that show up once AI systems move beyond demos. If it performs as advertised, teams can use it to split agent pipelines into smaller, more efficient steps instead of forcing a single large model to do everything.
Try Mellum2 in a local or self-hosted setup if you need private AI for code-heavy workflows. It is most useful when you want a fast routing layer, a lightweight sub-agent, or a model that can sit inside a larger orchestration system.
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