Let's find the inflection points, we'll need to solve the equation for this
$$\frac{d^{2}}{d x^{2}} f{\left(x \right)} = 0$$
(the second derivative equals zero),
the roots of this equation will be the inflection points for the specified function graph:
$$\frac{d^{2}}{d x^{2}} f{\left(x \right)} = $$
the second derivative$$\frac{2^{\operatorname{atan}{\left(x \right)}} \left(- 2 x + \log{\left(2 \right)}\right) \log{\left(2 \right)}}{\left(x^{2} + 1\right)^{2}} = 0$$
Solve this equationThe roots of this equation
$$x_{1} = \frac{\log{\left(2 \right)}}{2}$$
Сonvexity and concavity intervals:Let’s find the intervals where the function is convex or concave, for this look at the behaviour of the function at the inflection points:
Concave at the intervals
$$\left(-\infty, \frac{\log{\left(2 \right)}}{2}\right]$$
Convex at the intervals
$$\left[\frac{\log{\left(2 \right)}}{2}, \infty\right)$$