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$$\frac{\left(- \frac{4 x}{x^{2} + 1} + 1 + \frac{2 \left(\frac{4 x^{2}}{x^{2} + 1} - 1\right)}{x^{2} + 1}\right) e^{x}}{x^{2} + 1} = 0$$
Solve this equationThe roots of this equation
$$x_{1} = 1$$
$$x_{2} = - \frac{\sqrt[3]{6} \sqrt[3]{9 + \sqrt{87}}}{3} + \frac{6^{\frac{2}{3}}}{3 \sqrt[3]{9 + \sqrt{87}}} + 1$$
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
$$\left(-\infty, - \frac{\sqrt[3]{6} \sqrt[3]{9 + \sqrt{87}}}{3} + \frac{6^{\frac{2}{3}}}{3 \sqrt[3]{9 + \sqrt{87}}} + 1\right] \cup \left[1, \infty\right)$$
Convex at the intervals
$$\left[- \frac{\sqrt[3]{6} \sqrt[3]{9 + \sqrt{87}}}{3} + \frac{6^{\frac{2}{3}}}{3 \sqrt[3]{9 + \sqrt{87}}} + 1, 1\right]$$