For May 2026, golang/go delivered a significant enhancement to big integer arithmetic by introducing a new Int.Divide API and rounding-mode semantics in math/big. This enables precise quotient and remainder calculations for big.Int values with configurable rounding strategies, addressing a common need in financial, scientific, and systems software where exact control over rounding is required. The change also adds RoundingMode aliases (Trunc, Floor, Round, Ceil) to unify and simplify usage across codebases. Key work included a dedicated commit (8f7f951965120878db5158f543b88b8c0cd2323d) that adds Int.Divide and the rounding-mode aliases, plus accompanying tests and documentation. The work fixes issue #76821 and is tracked under golang/go#76820. Review and integration involved core maintainers Robert Griesemer, Damien Neil, and Peter Weinberger, with successful cross-team collaboration leading to a stable API surface in the standard library. Overall impact: expands Go's numerical capabilities, reduces edge-case division bugs in bigInt-heavy code, and strengthens the library for financial and systems applications. This aligns with business value by enabling safer, more predictable integer arithmetic in performance-critical code. Technologies/skills demonstrated: API design for math/big, Go review and integration process, test-driven development with rounding-mode coverage, cross-team collaboration, and documentation/PR hygiene.