Commercialization of lignins for high-value products should dramatically improve the biorefinery economy and help the growing industry to overcome current economical challenges. However, this requires lignin engineering to obtain products with optimized characteristics for specific applications. This paper reviews important issues of lignin engineering, such as developments in lignin structural analysis, application of small-scale high throughput methods to evaluate lignin performance as well as new achievements in valorization of biorefinery lignins (lignin-cellulose synergism, green and cost efficient methods to upgrade crude biorefinery lignins). These recent developments allow a reconsideration of biorefinery lignins as highvalue products for different applications.